OPERATING GUIDE

GPIB DC POWER SUPPLIES

Agilent Technologies Models
664xA, 665xA, 667xA, 668xA, and 669xA

Agilent Part No. 5964-8267 Printed in Malaysia

Microfiche Part No. 5964-8268 March, 2002
 Certification
Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory.
Agilent Technologies further certifies that its calibration measurements are traceable to the United States National
Institute of Standards and Technology, to the extent allowed by the Institute's calibration facility, and to the calibration
facilities of other International Standards Organization members.

Warranty
This Agilent Technologies hardware product is warranted against defects in material and workmanship for a period of three
years from date of delivery. Agilent Technologies software and firmware products, which are designated by Agilent
Technologies for use with a hardware product and when properly installed on that hardware product, are warranted not to
fail to execute their programming instructions due to defects in material and workmanship for a period of 90 days from date
of delivery. During the warranty period Agilent Technologies will, at its option, either repair or replace products which
prove to be defective. Agilent Technologies does not warrant that the operation of the software, firmware, or hardware shall
be uninterrupted or error free.

For warranty service, with the exception of warranty options, this product must be returned to a service facility designated
by Agilent Technologies. Customer shall prepay shipping charges by (and shall pay all duty and taxes) for products returned
to Agilent Technologies for warranty service. Except for products returned to Customer from another country, Agilent
Technologies shall pay for return of products to Customer.

Warranty services outside the country of initial purchase are included in Agilent Technologies' product price, only if
Customer pays Agilent Technologies international prices (defined as destination local currency price, or U.S. or Geneva
Export price).

If Agilent Technologies is unable, within a reasonable time to repair or replace any product to condition as warranted, the
Customer shall be entitled to a refund of the purchase price upon return of the product to Agilent Technologies.

Limitation of Warranty
The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer,
Customer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the environmental
specifications for the product, or improper site preparation and maintenance. NO OTHER WARRANTY IS EXPRESSED
OR IMPLIED. Agilent Technologies SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

Exclusive Remedies
THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER'S SOLE AND EXCLUSIVE REMEDIES. AGILENT
TECHNOLOGIES SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.

Assistance
The above statements apply only to the standard product warranty. Warranty options, extended support contracts, product
maintenance agreements and customer assistance agreements are also available. Contact your nearest Agilent
Technologies Sales and Service offices for further information on Agilent Technologies' full line of Support Programs.

2
Safety Summary
The following general safety precautions must be observed during all phases of operation, service, and repair of
this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual
violates safety standards of design, manufacture, and intended use of the instrument. Agilent Technologies
assumes no liability for the customer's failure to comply with these requirements.

GENERAL
Any LEDs used in this product are Class 1 LEDs as per IEC 825-l.
This ISM device complies with Canadian ICES-001. Cet appareil ISM est conforme à la norme NMB-001 du Canada.

ENVIRONMENTAL CONDITIONS

With the exceptions noted, all instruments are intended for indoor use in an installation category II1, pollution degree 2
environment. They are designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters.
Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range.
Exceptions: Agilent Technologies Models 6680A, 6681A, 6682A, 6683A, 6684A, 6690A, 6691A and 6692A are intended
for use in an installation category III2 environment.
1
Category II - Local level for connection to household outlets for 120 V, 230 V, etc.
2
Category III - Distribution level or cases where the reliability and availability of the equipment are subject to special requirements.

BEFORE APPLYING POWER

Verify that the product is set to match the available line voltage and the correct fuse is installed.

GROUND THE INSTRUMENT.

This product is a Safety Class 1 instrument (provided with a protective earth terminal). To minimize shock hazard, the
instrument chassis and cabinet must be connected to an electrical ground. The instrument must be connected to the ac mains
through a three-conductor power cable, with the third wire firmly connected to an electrical ground (safety ground) at the
power outlet. For instruments designed to be hard-wired to the ac power lines (supply mains), connect the protective earth
terminal to a protective conductor before any other connection is made. Any interruption of the protective (grounding)
conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal
injury. If the instrument is to be energized via an external autotransformer for voltage reduction, be certain that the
autotransformer common terminal is connected to the neutral (earthed pole) of the ac power lines (supply mains).

FUSES
Only fuses with the required rated current, voltage, and specified type (normal blow, time delay, etc.) should be used. Do
not use repaired fuses or short circuited fuseholders. To do so could cause a shock or fire hazard.

DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE

Do not operate the instrument in the presence of flammable gases or fumes.

KEEP AWAY FROM LIVE CIRCUITS

Operating personnel must not remove instrument covers. Component replacement and internal adjustments must be made by
qualified service personnel. Do not replace components with power cable connected. Under certain conditions, dangerous
voltages may exist even with the power cable removed. To avoid injuries, always disconnect power, discharge circuits and
remove external voltage sources before touching components.

DO NOT SERVICE OR ADJUST ALONE

Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is
present.
DO NOT EXCEED INPUT RATINGS
This instrument may be equipped with a line filter to reduce electromagnetic interference and must be connected to a
properly grounded receptacle to minimize electric shock hazard. Operation at line voltages or frequencies in excess of those
stated on the data plate may cause leakage currents in excess of 5.0 mA peak.
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT
Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized
modification to the instrument. Return the instrument to an Agilent Technologies Sales and Service Offices for service and
repair to ensure that safety features are maintained.
Instruments which appear damaged or defective should be made inoperative and secured against unintended operation until
they can be repaired by qualified service personnel.

3
 Safety Symbol Definitions
Symbol Description Symbol Description
Direct current Terminal for Line conductor on permanently
installed equipment
Alternating current Caution, risk of electric shock

Both direct and alternating current Caution, hot surface

Three-phase alternating current Caution (refer to accompanying documents)

Earth (ground) terminal In position of a bi-stable push control

Protective earth (ground) terminal Out position of a bi-stable push control

Frame or chassis terminal On (supply)

Terminal for Neutral conductor on Off (supply)

permanently installed equipment
Terminal is at earth potential(Used for Standby (supply). Units with this symbol are not
measurement and control circuits designed to completely disconnected from ac mains when this switch is
be operated with one terminal at earth off. To completely disconnect the unit from ac mains,
potential.) either disconnect the power cord or have a qualified
electrician install an external switch.

The CAUTION sign denotes a hazard. It calls

The WARNING sign denotes a hazard. It
attention to an operating procedure, or the like, which, if not correctly
calls attention to a procedure, practice, or the like, which, if
performed or adhered to, could result in damage to or destruction of part
not correctly performed or adhered to, could result in
or all of the product. Do not proceed beyond a CAUTION sign until the
personal injury. Do not proceed beyond a WARNING sign
indicated conditions are fully understood and met.
until the indicated conditions are fully understood and met.

Printing History
The edition and current revision of this manual are indicated below. Reprints of this manual containing minor corrections
and updates may have the same printing date. Revised editions are identified by a new printing date. A revised edition
incorporates all new or corrected material since the previous printing date. Changes to the manual occurring between
revisions are covered by change sheets shipped with the manual. In some cases, the manual change applies only to specific
instruments. Instructions provided on the change sheet will indicate if a particular change applies only to certain
instruments.
 Copyright 2001 Agilent Technologies Inc. Edition 1 - July, 2001
Update - March, 2002
This document contains proprietary information protected by copyright. All rights are reserved. No part of this document
may be photocopied, reproduced, or translated into another language without the prior consent of Agilent Technologies.
Information contained in this document is subject to change without notice.

Herstellerbescheinigung

Diese Information steht im Zusammenhang mit den Anforderungen der Maschinenläminformationsverordnung vom 18
Januar 1991. * Schalldruckpegel Lp <70 dB(A) * Am Arbeitsplatz * Normaler Betrieb * Nach EN 27779 (Typprufung).

Manufacturer's Declaration

This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 January
1991. * Sound Pressure Lp <70 dB(A) *At Operator Position * Normal Operation * According to EN 27779 (Type Test).

4
Declarations

DECLARATION OF CONFORMITY
According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014

Responsible Party Alternate Manufacturing Site

Manufacturer’s Name: Agilent Technologies, Inc. Agilent Technologies (Malaysia) Sdn. Bhd
Manufacturer’s Address: 140 Green Pond Road Malaysia Manufacturing
Rockaway, New Jersey Bayan Lepas Free Industrial Zone, PH III
07866 11900 Penang,
U.S.A Malaysia
declares that the Products:
Product Names: a) Single Output 200 Watt System dc Power Supplies
b) Single Output 200 Watt Manually Controlled dc Power Supplies
c) Single Output 500 Watt System dc Power Supplies
d) Single Output 500 Watt Manually Controlled dc Power Supplies
e) Single Output 500 Watt Solar Array Simulator

Model Numbers: a) 6641A, 6642A, 6643A, 6644A, 6645A

b) 6541A, 6542A, 6543A, 6544A, 6545A
c) 6651A, 6652A, 6653A, 6654A, 6655A
d) 6551A, 6552A, 6553A, 6554A, 6555A
e) E4350A, E4350B, E4351B

Product Options: This declaration covers all options and customized products based on the above products.

Conforms with the following European Directives:

The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive
89/336/EEC (including 93/68/EEC) and carries the CE Marking accordingly.

EMC information:
The product herewith complies with the requirements of the EMC Directive 89/336/EEC (including 93/68/EEC)
and carries the CE Marking accordingly (European Union).

As detailed in Electromagnetic Compatibility (EMC) Certificate of Conformance Number CC/TCF/00/074

based on Technical Construction File (TCF) HPNJ1, dated Oct. 27, 1997

Assessed by: Celestica Ltd, Appointed Competent Body

Westfields House, West Avenue
Kidsgrove, Stoke-on-Trent
Straffordshire, ST7 1TL
United Kingdom
Safety information:
The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and carries the CE-
marking accordingly.

Supplemental information
The product conforms to the following safety standards:
IEC 1010-1:1990+A1+A2 / EN 61010-1:1993 +A2
UL 3111-1:1994, UL 1244
CSA C22.2 No. 1010.1:1993

April 10, 2001

Date Hank Kowalla / Quality Manager at PPPGU

For further information, please contact your local Agilent Technologies sales office, agent or distributor.
Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Straβe 130, D71034 Böblingen, Germany

5
 DECLARATION OF CONFORMITY
According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014

Responsible Party Alternate Manufacturing Site

Manufacturer’s Name: Agilent Technologies, Inc. Agilent Technologies (Malaysia) Sdn. Bhd
Manufacturer’s Address: 140 Green Pond Road Malaysia Manufacturing
Rockaway, New Jersey Bayan Lepas Free Industrial Zone, PH III
07866 11900 Penang,
U.S.A Malaysia
declares that the Products:
Product Names: a) Single Output 2,000 Watt System dc Power Supplies
b) Single Output 2,000 Watt Manually Controlled dc Power Supplies
c) Single Output 5,000 Watt System dc Power Supplies
d) Single Output 6,670 Watt System dc Power Supplies

Model Numbers: a) 6671A, 6672A, 6673A, 6674A, 6675A

b) 6571A, 6572A, 6573A, 6574A, 6575A
c) 6680A, 6681A, 6682A, 6683A, 6684A
d) 6690A, 6691A, 6692A

Product Options: This declaration covers all options and customized products based on the above products.

Conforms with the following European Directives:

The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive
89/336/EEC (including 93/68/EEC) and carries the CE Marking accordingly.

EMC information:
The product herewith complies with the requirements of the EMC Directive 89/336/EEC (including 93/68/EEC)
and carries the CE Marking accordingly (European Union).

As detailed in Electromagnetic Compatibility (EMC) Certificate of Conformance Number CC/TCF/00/075

based on Technical Construction File (TCF) HPNJ2, dated Oct. 29, 1997

Assessed by: Celestica Ltd, Appointed Competent Body

Westfields House, West Avenue
Kidsgrove, Stoke-on-Trent
Straffordshire, ST7 1TL
United Kingdom
Safety information:
The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and carries the CE-
marking accordingly.

Supplemental information
The product conforms to the following safety standards:
IEC 1010-1:1990+A1+A2 / EN 61010-1:1993 +A2
UL 3111-1:1994, UL 1244
CSA C22.2 No. 1010.1:1993

July, 2001
Date Hank Kowalla / Quality Manager at PPPGU

For further information, please contact your local Agilent Technologies sales office, agent or distributor.
Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Straβe 130, D71034 Böblingen, Germany

6
Table of Contents
Certification 2
Safety Summary 3
Printing History 4
Declarations 5
Table of Contents 7

GENERAL INFORMATION 11
Introduction 11
Safety Considerations 12
Instrument Identification 12
Options 12
Accessories 13
Description 13
Front Panel Programming 14
Remote Programming 14
Analog Programming 14
Output Characteristic 15
General 15
Downprogramming 15
Specifications and Supplemental Characteristics 15

INSTALLATION 43
Inspection 43
Damage 43
Packaging Material 43
Items Supplied 43
Location and Temperature 44
Bench Operation 44
Rack Mounting 44
Temperature Performance 44
Input Power Source 45
Installing the Series 664xA and 665xA Power Cord 45
Installing the Series 667xA Power Cord 45
Installing the Series 668xA Power Cord 47
Installing the Series 669xA Power Cord 48

TURN-ON CHECKOUT 51
Introduction 51
Preliminary Checkout (All Models) 51
Power-On Checkout (All Models) 52
Using the Keypad (All Models) 52
Shifted Keys 52
Backspace Key 52
Output Checkout (All Models) 52
Checking the Voltage Function 53
Checking the Current Function 54
Checking the Save and Recall Functions (All Models) 55
Determining the GPIB Address (All Models) 55
In Case of Trouble 55
Line Fuse 55
Series 664xA and 665xA Supplies 56
Series 667xA Supplies 56

7
 Series 668xA Supplies 57
Series 669xA Supplies 57
Error Messages (All Models) 57
Selftest Errors 57
Power-On Error Messages 57
Checksum Errors. 58
Runtime Error Messages 58

USER CONNECTIONS 59
Rear Panel Connections (All Models) 59
Load Wire Selection (All Models) 59
Analog Connector (All Models) 60
Digital Connector (All Models) 60
Connecting Series 664xA and 665xA Power Supplies to the Load 61
Output Isolation 61
Load Considerations 61
Local Voltage Sensing 62
Remote Voltage Sensing 63
Connecting One Supply to the Load 64
Connecting Supplies in Auto-Parallel 65
Connecting Supplies in Series 67
External Voltage Control 67
Connecting Series 667xA Power Supplies to the Load 68
Output Isolation 68
Load Considerations 69
Local Voltage Sensing 70
Remote Voltage Sensing 70
Connecting One Power Supply to a Single Load 72
Connecting One Power Supply To Multiple Loads 72
Connecting Supplies in Auto-Parallel 73
Connecting Supplies in Series 74
External Voltage Control 75
Connecting Series 668xA and 669xA Power Supplies to the Load 76
Output Isolation 76
Load Considerations 76
Local Voltage Sensing 77
Remote Voltage Sensing 77
Connecting One Power Supply to a Single Load 79
Connecting One Power Supply to Multiple Loads 79
Connecting Supplies in Auto-Parallel 80
Connecting Supplies in Series 81
External Voltage Control 82
Controller Connections 83
Stand-Alone Connections 83
Linked Connections 83

FRONT PANEL OPERATION 85

Introduction 85
Getting Acquainted 85
Programming the Output 88
Establishing Initial Conditions 88
Programming Voltage 89
Programming Overvoltage Protection 89
Programming Current 90
Programming Overcurrent Protection 91
CV Mode vs. CC Mode 91

8
 Unregulated Operation 92
Saving and Recalling Operating States 92
Turn-On Conditions 92
Setting the GPIB Address 93
Types of Power Supply GPIB Addresses 93
Changing the Power Supply GPIB Address 93

CALIBRATION 95
Introduction 95
Equipment Required 95
General Procedure 95
Parameters Calibrated 95
Test Setup 96
Front Panel Calibration 96
Entering the Calibration Values 96
Saving the Calibration Constants 96
Disabling the Calibration Mode 96
Changing the Calibration Password 96
Recovering From Calibration Problems 99
Calibration Error Messages 99
Calibration Over the GPIB 100
Calibration Language Dictionary 100
CAL:CURR 100
CAL:CURR:LEV 100
CAL:CURR:MON (Series 668xA/669xA only) 101
CAL:PASS 101
CAL:SAVE 101
CAL:STAT 101
CAL:VOLT 102
CAL:VOLT:LEV 102
CAL:VOLT:PROT 102
Agilent BASIC Calibration Program 102

OPERATION VERIFICATION 105

Introduction 105
Test Equipment Required 105
List of Equipment 105
Current Monitoring Resistor 105
Performing the Tests 107
General Measurement Techniques 107
Programming the Power Supply 107
Order of Tests 107
Turn-on Checkout 107
Voltage Programming and Readback Accuracy 107
Current Programming and Readback Accuracy 108

LINE VOLTAGE CONVERSION 119

Series 664xA and 665xA Power Supplies 119
Series 667xA Power Supplies 120
Series 668xA/669xA Power Supplies 121

DIGITAL PORT FUNCTIONS 123

Digital Connector 123
Fault/Inhibit Operation 123
Changing the Port Configuration 126

9
 Digital I/O Operation 126
Relay Link Operation 127

CURRENT LOOP COMPENSATION (SERIES 668XA ONLY) 129

Introduction 129
Function of Loop Compensation 129
Setting The Loop Compensation Switch 132

USING AGILENT 668XA/669XA SERIES POWER SUPPLIES IN AUTOPARALLEL 133

Introduction 133

OUTPUT BUS BAR OPTIONS 135

Option 601 Installation 135
Option 602 Installation 136

INDEX 137

10
 1
General Information

Introduction
Two guides are shipped with your power supply - an Operating Guide (this document) and a Programming Guide. You will
find information on the following tasks in these guides:
1
Quick Document Orientation
Topic Location
Calibrating the power supply Appendix A - this guide
Compatibility programming language Appendix B - Programming Guide
Configuring the digital port Appendix D - this guide
Line voltage:
Connecting ac power source Chapter 2 - this guide
Converting the ac source voltage Appendix B - this guide
Source current, frequency, and power ratings Chapter 1- this guide
Operator replaceable parts Chapter 1- this guide
Operator troubleshooting Chapter 3 - this guide
Output impedance characteristics Chapter 1- this guide
Power supply accessories Chapter 1- this guide
Power supply operating characteristics Chapter 1- this guide
Power supply options Chapter 1- this guide
Power supply performance specifications Chapter 1- this guide
Programming
discrete fault inhibit (DFI) operation Chapter 4 - Programming Guide
from the analog port Chapter 4 - this guide
from the front panel Chapter 5 - this guide
over the GPIB Chapter 2 - Programming Guide
remote inhibit (RI) operation Chapter 4 - Programming Guide
status registers Chapter 4 - Programming Guide
Quick operating checkout (without load) Chapter 3 - this guide
Rack mounting Chapter 2 - this guide
SCPI programming language Chapter 3 - Programming Guide
Wiring
analog programming port Chapter 4 - this guide
discrete fault indicator (DFI) operation Appendix D - this guide
digital port Appendix D - this guide
GPIB controller Chapter 4 - this guide
load or loads Chapter 4 - this guide
local sensing Chapter 4 - this guide
remote inhibit (RI) operation Chapter 4 - this guide
remote sensing Chapter 4 - this guide
1
See the Table of Contents for complete list of topics.

General Information 11
Safety Considerations
This power supply is a Safety Class 1 instrument, which means it has a protective earth terminal. That terminal must be
connected to earth ground through a power source equipped with a 3-wire ground receptacle. Refer to the Safety Summary
page at the beginning of this guide for general safety information. Before installation or operation, check the power supply
and review this guide for safety warnings and instructions. Safety warnings for specific procedures are located at
appropriate places in the guide. warning

Instrument Identification
The power supply is identified by a unique serial number that provides the following information:
US = The letter indicates the country of manufacture, where US = USA; MY = Malaysia.
33430177 = The first four digits indicate the year and week of manufacture or last significant design change. Add 1960 to
the first two digits to determine the year. For example, 32=1992, 33=1993, etc. The third and forth digits
specify the week of the year (43 = the 43rd week). The last four digits is the number assigned to each unit.

Options

Option Description Used with Agilent Series

664xA 665xA 667xA 668xA 669xA
100 Input power 87-106 Vac, with power cord x x
120 Input power 104-127 Vac, with power cord x x
220 Input power 191-233 Vac, with power cord x x
240 Input power 209-250 Vac, with power cord x x
200 Input power 174-220 Vac, without power cord x
230 Input power 191-250 Vac, without power cord x
208 Input power 180-235 Vac, 3-phase, without power cord x x
400 Input power 360-440 Vac, 3-phase, without power cord x x
601 Output connector kit required for bench applications x x
602 Bus bar spacers for paralleling power supplies x x
831 Power cord, 12 AWG, UL listed, CSA certified, without plug x
2
832 Power cord, 4mm , harmonized, without plug x
834 Power cord, 10 AWG, UL listed, CSA certified, without plug x
841 Power cord, 12 AWG, UL listed, CSA certified, with NEMA x
6-20P 20A/250V plug
842 Power cord, 4mm2, harmonized, with IEC309 32A/220V plug x
843 Power cord, 12 AWG, UL listed, CSA certified, with JIS x
C8303 25A/250V plug
844 Power cord, 10 AWG, UL listed, CSA certified, with NEMA x
L6-30P-30A/250V locking plug
861 Power cord, 10 AWG, 4-wire, 300V, 25A, 90°C, UL listed, x
CSA certified, without plug
Power cord, 8 AWG, 4-wire, 300 V, 35A, 90°C, UL listed, x
CSA certified, without plug
862 Power cord, 2.5mm2, 4-wire, 450V, 20A, 70°C, harmonized, x x
without plug

12 General Information
 List of Options (continued)
Option Description Used with Agilent Series
664xA 665xA 667xA 668xA 669xA
908 Rack mount kit (Agilent 5062-3974) x
Rack mount kit (Agilent 5062-3977) x x
Support rails (E3663AC) are required.
Rack mount kit (Agilent 5062-3977 & 5062-3974) x x
Support rails (E3663AC) are required.
909 Rack mount kit with handles (Agilent 5062-3975) x
Rack mount kit with handles (Agilent 5062-3983) x x
Support rails (E3663AC) are required.
Rack mount kit with handles (Agilent 5062-3983 & x x
5062-3974)
Support rails (E3663AC) are required.

Accessories

Description Agilent No.

Fuse replacement kit for Series 668xA
16 AM for 360-440 Vac, 3-phase line 5060-3512
30 AM for 180-235 Vac, 3-phase line 5060-3513
Fuse replacement kit for Series 669xA
16 AM for 360-440 Vac, 3-phase line 2110-1077
30 AM for 180-235 Vac, 3-phase line 2110-1078
GPIB cable (all models)
0.5 meters (1.6 ft) 10833D
1.0 meter (3.3 ft) 10833A
2.0 meters (6.6 ft) 10833B
4.0 meters ( 13 .2 ft) 10833C
Serial link cable (all models)
2.0 meters (6.6 ft) 5080-2148
Slide mount kit
heavy duty, for Series 667xA/668xA/669xA 1494-0058
standard, for Series 665xA 1494-0059
standard, for Series 664xA 1494-0060

Description
These units form a family of unipolar, GPIB programmable power supplies organized as follows:

Family Power Agilent Models

Series 664xA 200 W 6641A, 6642A, 6643A, 6644A, 6645A
Series 665xA 500 W 6651A, 6652A, 6653A, 6654A, 6655A
Series 667xA 2000 W 6671A, 6672A, 6673A, 6674A, 6675A
Series 668xA 5000 W 6680A, 6681A, 6682A, 6683A, 6684A
Series 669xA 6670 W 6690A, 6691A, 6692A

Each power supply is programmable locally from the front panel or remotely via a rear-panel analog control port.

General Information 13
Operational features include:

n Constant voltage (CV) or constant current (CC) output over the rated output range.
n Built-in overvoltage (OV), overcurrent (OC), and overtemperature (OT) protection.
n Automatic turn-on selftest.
n Pushbutton nonvolatile storage and recall of up to 5 operating states (4 in Series 668xA/669xA supplies).
n Local or remote sensing of output voltage.
n Auto-parallel operation for increased total current.
n Series operation for increased total voltage.
n Analog input for remote programming of voltage and current.
n Voltage output for external monitoring of output current.
n User calibration from the front panel.

Front Panel Programming

The front panel has both rotary (RPG) and keypad controls for setting the output voltage and current. The panel display
provides digital readouts of the output voltage and current. Other front panel controls permit:

n Enabling or disabling the output.

n Setting the overvoltage protection (OVP) trip voltage.
n Enabling or disabling the overcurrent protection (OCP) feature.
n Saving and recalling operating states.
n Setting the GPIB address.
n Reading GPIB error message codes.
n Calibrating the power supply, including changing the calibration protection password.

Remote Programming

The power supply may be remotely programmed via the GPIB bus and/or from an analog input port. GPIB programming is
with SCPI (Standard Commands for Programmable Instruments) commands that make the power supply programs
compatible with those of other GPIB instruments. (A software-controlled Compatibility Mode also permits programming in
the command set of the Agilent 6030xA Autoranging Series.) In addition to control functions, SCPI programming permits
writing to the front panel LCD and complete calibration functions. Power supply status registers permit remote monitoring
of the following conditions:

n Overvoltage, overcurrent, overtemperature, and unregulated states.

n Operating mode (constant voltage or constant current).
n State of the RI (remote inhibit) input signal.
n Power-on status (PON).
n Status of the output queue (QYE).
n Pending triggers (WTG).
n GPIB interface programming errors (CME, DDE, and EXE).
n Calibration state (enabled or disabled).

The status registers can be programmed to generate an output fault signal (FLT) upon the occurrence of one or more
selected status events.

Analog Programming
The power supply has an analog port for remote programming. The output voltage and/or current of the power supply may
be controlled by individual dc programming voltages applied to this port. The port also provides a monitor output that
supplies a dc voltage proportional to the output current.

14 General Information
Output Characteristic

General
The power supply can operate in either CV (constant voltage) or CC (constant current) over its voltage and current ratings
(see Table 1-l). The operating locus is shown by the Output Characteristic Curve in Table 1-2. The operating point is
determined by the voltage setting (Vs), the current setting (Is), and the load impedance. Two operating points are shown.
Point 1 is defined by the load line cutting the operating locus in the constant-voltage region. This region defines the CV
mode. Point 2 is defined by the load line cutting the operating locus in the constant-current region. This region defines the
CC mode.

Downprogramming
The power supply can sink current for more rapid down programming in the CV mode. For Series 664xA and 665xA
supplies, this capability is defined by the second quadrant area (-Is) of the Output Characteristic Curve. These supplies can
sink about 20% of their maximum rated positive output current. For Series 667xA, 668xA, and 669xA power supplies, this
is an uncharacterized current-sinking area that provides a limited downprogramming capability.

Specifications and Supplemental Characteristics

Tables 1-1 through 1-4 list the specifications and supplemental characteristics for the Series 664xA, 665xA, 667xA, 668xA,
and 669xA power supplies. The organization is as follows:

Series Specifications Characteristics

6641A-6645A Table l-la Table l-lb
6651A-6655A Table 1-2a Table 1-2b
6671A-6675A Table 1-3a Table 1-3b
6680A-6684A Table 1-4a Table 1-4b
6690A-6692A Table 1-5a Table 1-5b

Specifications are performance parameters warranted over the specified temperature range.

Supplemental Characteristics are not warranted but are descriptions of performance determined either by design or type
testing.

General Information 15
 1
Table 1-1a. Performance Specifications for Series 664xA
Parameter Agilent Model Number
6641A 6642A 6643A 6644A 6645A
Output Ratings
Voltage: 0-8V 0 - 20 V 0 - 35 V 0 - 60 V 0 - 120 V
Current:@ 40°C 0 - 20 A 0 - 10 A 0-6A 0 - 3.5 A 0 - 1.5 A
Current:@ 50°C 0 - 18 A 0-9A 0 - 5.4 A 0 - 3.2 A 0 - 1.4 A
Current:@ 55°C 0 - 17 A 0 - 8.5 A 0 - 5.1 A 0 - 3.0 A 0 -1.4 A

Programming Accuracy (@ 25 ± 5 °C)

Voltage: 0.06% + 5 mV 10 mV 15 mV 26 mV 51 mV

Current: 0 . l5 % + 26 mA 13 mA 6.7 mA 4.1 mA 1.7 mA

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Voltage: rms 300 µV 300 µV 400 µV 500 µV 700 µV
Constant Voltage: p-p 3 mV 3 mV 4 mV 5 mV 7 mV
Constant Current: rms 10 mA 5 mA 3 mA 1.5 mA 1 mA

Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ±:5 °C)
Voltage: 0.07% + 6 mV 15 mV 25 mV 40 mV 80 mV
+Current 0.15% + 18 mA 9.1 mA 5 mA 3 mA 1.3 mA
-Current 0.35% + 40 mA 20 mA 12 mA 6.8 mA 2.9 mA

Load Regulation (change in output voltage or current for any load change within ratings)
Voltage 1 mV 2 mV 3 mV 4 mV 5 mV
Current: 1 mA 0.5 mA 0.25 mA 0.25 mA 0.25 mA

Line Regulation (change in output voltage or current for any line change within ratings
Voltage: 0.5 mV 0.5 mV 1 mV 1 mV 2 mV
Current: 1 mA 0.5 mA 0.25 mA 0.25 mA 0.25 mA

Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.

< 100 µs
AC Input Ratings (selectable via internal switching - see Appendix B)
Nominal line voltage
100,120,220,240 Vac: -13%, +6 %
230 Vac: -10%, +10%
Frequency range: 47-63 Hz

Output Terminal Isolation ±240 Vdc (maximum, from chassis ground)

Notes: 1For Supplemental Characteristics, see Table 1-1b.

16 General Information
 1
Table 1-1b. Supplemental Characteristics for Series 664xA
Parameter Agilent Model Number
6641A 6642A 6643A 6644A 6645A
Output Programming Range (maximum programmable values)

Voltage: 8.190 V 20.475 V 35.831 V 61.425 V 122.85 V

Current: 20.475 A 10.237 A 6.142 A 3.583 A 1.535 A
Overvoltage Protection (OVP): 8.8 V 22.0 V 38.5 V 66.0 V 132.0 V

Average Resolution
Voltage: 2 mV 5 mV 10 mV 15 mV 30 mV
Current: 6 mA 3 mA 2 mA 1.2 mA 0.5 mA
Overvoltage Protection (OVP): 13 mV 30 mV 54 mV 93 mV 190 mV

Accuracy
Overvoltage Protection (OVP): 160 mV 400 mV 700 mV 1.2 V 2.4 V
Analog Programming (VP):*
0.36% + 6 mV 15 mV 27 mV 45 mV 90 mV
Analog Programming (IP):*
7.6% + 18 mA 9.2 mA
1.5% + 5.5 mA 3.2 mA 1.4 mA
Current Monitor (+IM):*
7.7% + 65 mA 32 mA
1.6 % + 8.1 mA 7.1 mA 1.8 mA
*Referenced to supply output
Drift Temperature Stability (following a 30-minute warmup, change in output over 8 hours under constant line, load,
and ambient temperature)

Voltage: 0.02% + 0.4 mV 1 mV 2 mV 3 mV 6 mV

Current: 0.02% + 16 mA 6 mA 3 mA 2 mA 1 mA
Temperature Coefficients (change per °C)

Voltage: 60 ppm + 0.1 mV 0.2 mV 0.3 mV 0.5 mV 1.1 mV

+Current: 95 ppm + 0.82 mA 0.41 mA 0.18 mA 0.12 mA 0.04 mA
Voltage Readback: 60 ppm + 0.2 mV 0.5 mV 0.75 mV 1.3 mV 2.6 mV
+Current Readback: 95 ppm + 1.2 mA 0.62 mA 0.33 mA 0.20 mA 0.08 mA
--Current Readback: 110 ppm + 1.2 mA 0.62 mA 0.33 mA 0.20 mA 0.08 mA
Overvoltage Protection (OVP):
200 ppm + 1.6 mV 3.3 mV 5 mV 13 mV 24 mV
Analog Programming (VP):
60 ppm + 0.1 mV 0.25 mV 0.4 mV 0.7 mV 1.25 mV
Analog Programming (IP):
90 ppm + 0.56 mA 0.28 mA 0.17 mA 0.1 mA 0.04 mA
Current Monitor (+IM):
75 ppm + 0.61 mA 0.3 mA 0.06 mA 0.06 mA 0.02 mA
Maximum Input Power: 480 VA; 400 W, 60 W with no load
1
Notes: For Performance Specifications, see Table 1-la.

General Information 17
 1
Table 1-lb. Supplemental Characteristics for Series 664xA (continued)
Parameter Agilent Model Number
6641A 6642A 6643A 6644A 6645A
Maximum AC Line Current Ratings
100 Vac nominal: 4.4 A rms
120 Vac nominal: 3.8 A rms
220 Vac nominal: 2.2 A rms
230 Vac nominal: 2.1 A rms
240 Vac nominal: 2.0 A rms
Maximum Reverse Bias Current: With AC input power applied and the dc output reverse
biased by an external dc source, the supply will continuously
withstand without damage a current equal to its output
current rating (see Table 1- 1a).
Remote Sensing Capability
Voltage Drop Per Lead: Up to 1/2 of rated output voltage.

Load Regulation: Add 3 mV to spec (see Table l-la) for each l-volt change in
the + output lead due to load current changes.

Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply
is connected directly to the GPIB Bus):
20 ms
Downprogrammer Current Capability (± 15%):
5.8 A 2.5 A 1.5 A 0.9 A 0.75 A
Output Voltage Programming Response Time
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):

<15 ms
Settling Time (time for output change to settle within 1 LSB (0.025% x rated voltage) of its final value):

<60 ms
Monotonicity: Output is monotonic over entire rated voltage, current, and
temperature range.
Auto-Parallel Configuration: Up to 3 identical models

Analog Programming (IP & VP)

Input Signal:* 0 to -5 V
Input Impedance: 10 kΩ, nominal
*Signal source must be isolated.
Current Monitor Output (+IM): 0 to -5 V represents zero to full-scale current output

Savable States
Nonvolatile Memory Locations: 5 ( 0 through 4)
Nonvolatile Memory Write Cycles: 40,000, typical
Prestored State (factory default): Location 0

Notes: lFor Performance Specifications, see Table l-la.

18 General Information
 1
Table 1-1b. Supplemental Characteristics for Series 664xA (continued)
Parameter All Models
Digital Port Characteristics (see Table 1-5)

GPIB Interface Capabilities (see Table 1-5)

Serial Link Capabilities (see Table 1-5)

Recommended Calibration Interval: 1 year

Safety Compliance
Complies with: CSA 22.2 No.231,IEC 348
Designed to comply with: UL 1244

RFI Suppression (complies with): CISPR-ll, Group 1, Class B

Dimensions
Width: 425.5 mm (16.75 in)
Height (including removable feet): 88.1 mm (3.5 in)
Depth (including safety cover): 439 mm (17.3 in)

Note 1: For Performance Specifications, see Table l-la.:

Weight
Net: 14.2 kg (31.4 lb)
Shipping: 16.3 kg (36 lb)

Output Characteristic Curve:

Notes: lFor Performance Specifications, see Table l-la.

General Information 19
 1
Table 1-1b. Supplemental Characteristics for Series 664xA (continued)
Parameter All Models
Output Impedance Curves (Typical):

Notes: lFor Performance Specifications, see Table l-la.

20 General Information
 1
Table 1-2a. Performance Specifications for Series 665xA
Parameter Agilent Model Number
6651A 6652A 6653A 6654A 6655A
Output Ratings
Voltage: 0-8V 0 - 20 V 0- 35 V 0 - 60 V 0 - 120 V
Current:@ 40°C 0 - 50 A 0 - 25 A 0 - 15 A 0-9A 0-4A
Current:@ 50°C 0 - 45 A 0 - 22.5 A 0 - 13.5 A 0 - 8.1 A 0 - 3.6 A
Current:@ 55°C 0 - 42.5 A 0 - 21.3 A 0 - 12.8 A 0 - 7.7 A 0 -3.4 A

Programming Accuracy (@ 25 ± 5 °C)

Voltage: 0.06% + 5 mV 10 mV 15 mV 26 mV 51 mV

Current: 0 . l5 % + 60 mA 25 mA 13 mA 8 mA 4 mA

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Voltage: rms 300 µV 300 µV 400 µV 500 µV 700 µV
Constant Voltage: p-p 3 mV 3 mV 4 mV 5 mV 7 mV
Constant Current: rms 25 mA 10 mA 5 mA 3 mA 2 mA

Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ± 5 °C)
Voltage: 0.07% + 6 mV 15 mV 25 mV 40 mV 80 mV
+Current 0.15% + 67 mA 26 mA 15 mA 7 mA 3 mA
-Current 0.35% + 100 mA 44 mA 24 mA 15 mA 7 mA

Load Regulation (change in output voltage or current for any load change within ratings)
Voltage: 1 mV 2 mV 3 mV 4 mV 5 mV
Current: 2 mA 1 mA 0.5 mA 0.5 mA 0.5 mA

Line Regulation (change in output voltage or current for any line change within ratings
Voltage: 0.5 mV 0.5 mV 1 mV 1 mV 2 mV
Current: 2 mA 1 mA 0.75 mA 0.5 mA 0.5 mA

Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.

< 100 µs
AC Input Ratings (selectable via internal switching - see Appendix B)
Nominal line voltage
100,120,220,240 Vac: -13%, +6 %
230 Vac: -10%, +10%
Frequency range: 47-63 Hz

Output Terminal Isolation ±240 Vdc (maximum, from chassis ground)

Notes: 1For Supplemental Characteristics, see Table 1-2b.

General Information 21
 1
Table 1-2b. Supplemental Characteristics for Series 665xA
Parameter Agilent Model Number

6651A 6652A 6653A 6654A 6655A

Output Programming Range (maximum programmable values)

Voltage: 8.190 V 20.475 V 35.831 V 61.425 V 122.85 V

Current: 51.188 A 25.594 A 15.356 A 9.214 A 4.095 A
Overvoltage Protection (OVP): 8.8 V 22.0 V 38.5 V 66.0 V 132.0 V

Average Resolution
Voltage: 2 mV 5 mV 10 mV 15 mV 30 mV
Current: 15 mA 7 mA 4 mA 2.5 mA 1 mA
Overvoltage Protection (OVP): 13 mV 30 mV 54 mV 93 mV 190 mV

Accuracy
Overvoltage Protection (OVP):* 160 mV 400 mV 700 mV 1.2 V 2.4 V
Analog Programming (VP):*
0.36% + 6 mV 15 mV 27 mV 45 mV 90 mV
Analog Programming (IP):*
7% + 75 mA 31 mA 16 mA 8 mA 5 mA
Current Monitor (+IM):*
7% + 730 mA 400 mA 120 mA 80 mA 75 mA
*Referenced to supply output
Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,
load, and ambient temperature)

Voltage: 0.02% + 0.4 mV 1 mV 2 mV 3 mV 6 mV

Current: 0.02% + 40 mA 15 mA 8 mA 5 mA 2.5 mA
Temperature Coefficients (change per °C)

Voltage: 60 ppm + 0.1 mV 0.2 mV 0.3 mV 0.5 mV 1.1 mV

+Current: 90 ppm + 1.4 mA 0.7 mA 0.3 mA 0.2 mA 0.2 mA
Voltage Readback: 60 ppm + 0.2 mV 0.5 mV 0.75 mV 1.3 mV 2.6 mV
+Current Readback: 90 ppm + 1.7 mA 0.9 mA 0.5 mA 0.3 mA 0.2 mA
-Current Readback: 105 ppm + 1.7 mA 0.9 mA 0.5 mA 0.3 mA 0.2 mA
Overvoltage Protection (OVP):
200 ppm + 1.6 mV 3.3 mV 5 mV 13 mV 24 mV
Analog Programming (VP):
60 ppm + 0.1 mV 0.25 mV 0.4 mV 0.7 mV 1.25 mV
Analog Programming (IP):
90 ppm + 1.4 mA 0.7 mA 0.3 mA 0.2 mA 0.15 mA
Current Monitor (+IM):
80 ppm + 1.4 mA 0.7 mA 0.3 mA 0.2 mA 0.15 mA
Maximum Input Power 1380 VA; 1100 W, 120 W with no load
1
Notes: For Performance Specifications, see Table 1-2a.

22 General Information
 1
Table 1-2b. Supplemental Characteristics for Series 665xA (continued)
Parameter Agilent Model Number
6651A 6652A 6653A 6654A 6655A
Maximum AC Line Current Ratings
100 Vac nominal: 12 A rms (15 AM fuse)
120 Vac nominal: 10 A rms (12 AM fuse)
220 Vac nominal: 5.7 A rms (7 AM fuse)
230 Vac nominal: 5.5 A rms (7 AM fuse)
240 Vac nominal: 5.3 A rms (7 AM fuse)
Maximum Reverse Bias Current: With AC input power applied and the dc output reverse
biased by an external dc source, the supply will continuously
withstand without damage a current equal to its output
current rating (see Table 1- 2a) .
Remote Sensing Capability
Voltage Drop Per Lead: Up to 1/2 of rated output voltage.

Load Regulation: Add 3 mV to spec (see Table l-2a) for each l-volt change in
the + output lead due to load current changes.

Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply
is connected directly to the GPIB Bus):
20 ms
Downprogrammer Current Capability (± 15%):
11.6 A 5A 3A 1.8 A 1.5 A
Output Voltage Programming Response Time
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):

<15 ms
Settling Time (time for output change to settle within 1 LSB (0.025% x rated voltage) of its final value):

<60 ms
Monotonicity: Output is monotonic over entire rated voltage, current, and
temperature range.
Auto-Parallel Configuration: Up to 3 identical models

Analog Programming (IP & VP)

Input Signal:* 0 to -5 V
Input Impedance: 10 kΩ, nominal
*Signal source must be isolated.
Current Monitor Output (+IM): 0 to -5 V represents zero to full-scale current output.

Savable States
Nonvolatile Memory Locations: 5 ( 0 through 4)
Nonvolatile Memory Write Cycles: 40,000, typical
Prestored State (factory default): Location 0

Notes: lFor Performance Specifications, see Table l-2a.

General Information 23
 1
Table 1-2b. Supplemental Characteristics for Series 665xA (continued)
Parameter All Models
Digital Port Characteristics (see Table 1-5)

GPIB Interface Capabilities (see Table 1-5)

Serial Link Capabilities (see Table 1-5)

Recommended Calibration Interval: 1 year

Safety Compliance
Complies with: CSA 22.2 No.231,IEC 348
Designed to comply with: UL 1244

RFI Suppression (complies with): CISPR-ll, Group 1, Class B

Dimensions
Width: 425.5 mm (16.75 in)
Height (including removable feet): 132.6 mm (5.22 in)
Depth (including safety cover): 497.8 mm (19.6 in)

Weight
Net: 25 kg (54 lb)
Shipping: 28 kg (61 lb)

Output Characteristic Curve:

Notes: lFor Performance Specifications, see Table l-2a.

24 General Information
 1
Table 1-2b. Supplemental Characteristics for Series 665xA (continued)
Parameter All Models
Output Impedance Curves (Typical):

Notes: lFor Performance Specifications, see Table l-2a.

General Information 25
 1
Table 1-3a. Performance Specifications for Series 667xA
Parameter Agilent Model Number
6671A 6672A 6673A 6674A 6675A
Output Ratings
Voltage: 0-8V 0 - 20 V 0- 35 V 0 - 60 V 0 - 120 V
Current:@ 0 to 55°C 0 - 220 A 0 - 100 A 0 - 60 A 0 - 35 A 0 - 18 A
Programming Accuracy (@ calibration temperature* ± 5 °C)

Voltage: 0.04% + 8 mV 20 mV 35 mV 60 mV 120 mV

Current: 0.l%+ 125 mA 60 mA 40 mA 25 mA 12 mA

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Voltage: rms 650 µV 750 µV 800 µV 1.25 mV 1.9 mV
Constant Voltage: p-p 7 mV 9 mV 9 mV 11 mV 16 mV
Constant Current: rms 200 mA 100 mA 40 mA 25 mA 12 mA

Readback Accuracy (from front panel or over GPIB with respect to actual output @ calibration temp1 ± 5 °C)
Voltage: 0.05% + 12 mV 30 mV 50 mV 90 mV 180 mV
±Current: 0.1% + 150 mA 100 mA 60 mA 35 mA 18 mA
Load Regulation (change in output voltage or current for any load change within ratings)
Voltage: 0.002% + 300 µV 650 µV 1.2 mV 2 mV 4 mV
Current: 0.005% + 10 mA 7 mA 4 mA 2 mA 1 mA
Line Regulation (change in output voltage or current for any line change within ratings
Voltage: 0.002% + 300 µV 650 µV 1.2 mV 2 mV 4 mV
Current: 0.005% + 10 mA 7 mA 4 mA 2 mA 1 mA
bisep>
Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.

< 900 µs
AC Input Ratings (selectable via internal switching - see Appendix B)
Nominal line voltage
200 Vac:* 174-220 Vac
*below 185 Vac, derate output voltage 7.8 V 18.0 V 31.5 V 56.5 V 108 V
linearly to :
230 Vac: 191-250 Vac
Frequency range: 47-63 Hz

Output Terminal Isolation ±240 Vdc (maximum, from chassis ground)

Notes: 1For Supplemental Characteristics, see Table 1-3b.

26 General Information
 1
Table 1-3b. Supplemental Characteristics for Series 667xA
Parameter Agilent Model Number

6671A 6672A 6673A 6674A 6675A

Output Programming Range (maximum programmable values)

Voltage: 8.190 V 20.475 V 35.831 V 61.425 V 122.85 V

Current: 225.23 A 102.37 A 61.43 A 35.83 A 18.43 A
Overvoltage Protection (OVP): 10.0 V 24.0 V 42.0 V 72.0 V 144.0 V

Typical Resolution
Voltage: 2 mV 5 mV 10 mV 15 mV 30 mV
Current: 55 mA 25 mA 15 mA 8.75 mA 4.5 mA
Overvoltage Protection (OVP): 15 mV 35 mV 65 mV 100 mV 215 mV

Accuracy ( @ calibration temp ±5 °C)*

Overvoltage Protection (OVP):* 200 mV 500 mV 900 mV 1.15 V 3.0 V
Analog Programming (VP): ± 0.3%
Analog Programming (IP): ± 7%
Current Monitor (+IM): ±7%
*Calibration temp = 25° C
Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,
load, and ambient temperature)

Voltage: 0.02% + 0.24 mV 0.6 mV 1 mV 1.8 mV 3.6 mV

Current: 0.02% + 69 mA 35 mA 20 mA 10 mA 6 mA
Temperature Coefficients (change per °C after 30-minute warmup)

Voltage: 50 ppm + 0.04 mV 0.2 mV 0.7 mV 1.2 mV 2.4 mV

Current: 75 ppm + 25 mA 12 mA 7 mA 4 mA 2 mA
Voltage Readback: 60 ppm + 0.1 mV 0.3 mV 1 mV 1.2 mV 3 mV
±Current Readback: 85 ppm + 30 mA 15 mA 9 mA 5 mA 2.5 mA
Overvoltage Protection (OVP):
200 ppm + 1.8 mV 5 mV 8 mV 13 mV 25 mV
Analog Programming (VP):
60 ppm + 0.1 mV 0.3 mV 0.5 mV 0.7 mV 1.5 mV
Analog Programming (±IP):
275 ppm + 26 mA 14 mA 9 mA 5 mA 3 mA
Current Monitor (+IM):
50 ppm + 3 mA 2 mA 1 mA 0.6 mA 0.3 mA
Maximum Input VA and Power 3800 VA; 2600 W, 100 W with no load
Maximum AC Line Current Ratings
200 Vac 19 A rms (25 AM fuse)
nominal:
230 Vac 19 A rms (25 AM fuse)
nominal:
Maximum Reverse Bias Current: With AC input power applied and the dc output reverse biased by an
external dc source, the supply will continuously withstand without damage a
current equal to its output current rating (see Table 1-3a).
1
Notes: For Performance Specifications, see Table 1-3a.

General Information 27
 1
Table 1-3b. Supplemental Characteristics for Series 667xA (continued)
Parameter Agilent Model Number
6671A 6672A 6673A 6674A 6675A
Remote Sensing Capability
Voltage Drop Per Lead: Up to 1/2 of rated output voltage.
Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.

Load Regulation:
Degradation due to load lead drop in--output: ∆mV (regulation) = Vdrop(Rsense- )/k
Degradation due to load lead drop in + output:
∆mV (regulation) = Vdrop(Rsense +)/k + 2Vdrop(Vrating)/(Vrating + 10 V)
where Rsense - and Rsense + are resistances of respective sense leads and k is the following model-dependent
value:
6671A=1; 6672A=1.82; 6673A=4.99; 6674A=10; 6675A=16.2

Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply
is connected directly to the GPIB Bus):
20 ms
Output Voltage Programming Response Time**
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):***

30 ms 60 ms 130 ms 130 ms 195 ms

Full-load programming speed up/down time (time for output to settle within 4 LSBs of the final value):***

85 ms 190 ms 380 ms 380 ms 600 ms

No-load downprogrammiug discharge time (time for output to fall to 0.5 V when programmed from full voltage to
zero volts):
130 ms 250 ms 350 ms 600 ms 600 ms
** All values exclude command processing time.
*** With full resistive load = VRATED/IRATED.
Monotonicity: Output is monotonic over entire rated voltage, current, and
temperature range.
Auto-Parallel Configuration: Up to 3 identical models

Analog Programming (IP & VP)

Input Signal:*
VP Input Signal:** (0 to ) -4.72 V -4.24 V -4.25 V -4.24 V -3.97 V
VP Input Impedance: 60 kΩ, nominal
IP to -IP Differential Input Signal: (0 to ) +7.79 V +6.81 V +6.81 V =7.01 V +6.34 V
*Signal source must be isolated.
** Referenced to output signal common.
Current Monitor Output (+IM):
Output Signal:* (-0.25 to ) +9.05 V +7.70 V +7.70 V +7.93 v +7.15 V
Output Impedance: 490 Ω
* Corresponds to 0% to 100% output current.
Savable States
Nonvolatile Memory Locations: 5 ( 0 through 4)
Nonvolatile Memory Write Cycles: 40,000, typical
Prestored State (factory default): Location 0

Notes: lFor Performance Specifications, see Table l-3a.

28 General Information
 1
Table 1-3b. Supplemental Characteristics for Series 667xA (continued)
Parameter All Models
Digital Port Characteristics (see Table 1-5)

GPIB Interface Capabilities (see Table 1-5)

Serial Link Capabilities (see Table 1-5)

Recommended Calibration Interval: 1 year

Safety Compliance
Complies with: CSA 22.2 No.231,IEC 348
Designed to comply with: UL 1244

RFI Suppression (complies with): CISPR-ll, Group 1, Class B

Dimensions
Width: 425.5 mm (16.75 in)
Height (including removable feet): 145.1 mm (5.71 in)
Depth (including safety cover): 640 mm (25.2 in)

Weight
Net: 27.7 kg (61 lb)
Shipping: 31.4 kg (69 lb)

Output Characteristic Curve:

Notes: lFor Performance Specifications, see Table l-3a.

General Information 29
 1
Table 1-3b. Supplemental Characteristics for Series 667xA (continued)
Parameter All Models
Output Impedance Curves (Typical):

Notes: lFor Performance Specifications, see Table l-3a.

30 General Information
 1
Table 1-4a. Performance Specifications for Series 668xA
Parameter Agilent Model Number
6680A 6681A 6682A 6683A 6684A
Output Ratings
Voltage: 0-5V 0-8V 0- 21 V 0 - 32 V 0 - 40 V
Current:* 0 - 875 A 0 - 580 A 0 - 240 A 0 - 160 A 0 - 128 A
*Derated linearly 1%/°C from 40 ° C to 55 °C

Programming Accuracy (@ 25 ± 5 °C)

Voltage: 0.04% + 5 mV 8 mV 21 mV 32 mV 40 mV
Current: 0.l%+ 450 mA 300 mA 125 mA 85 mA 65 mA

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Voltage: rms 1.5 mV 1.5 mV 1.5 mV 1.0 mV 1.0 mV
Constant Voltage: p-p 10 mV 10 mV 10 mV 10 mV 10 mV

Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ± 5 °C)
Voltage: 0.05% + 7.5 mV 12 mV 32 mV 48 mV 60 mV
±Current 0.1% + 600 mA 400 mA 165 mA 110 mA 90 mA

Load Regulation (change in output voltage or current for any load change within ratings)
Voltage 0.002% + 190 µV 300 µV 650 µV 1.1 mV 1.5 mV
Current: 0.005% + 65 mA 40 mA 17 mA 12 mA 9 mA

Line Regulation (change in output voltage or current for any line change within ratings)
Voltage: 0.002% + 190 µV 300 µV 650 µV 1.1 mV 1.5 mV
Current: 0.005% + 65 mA 40 mA 17 mA 12 mA 9 mA

Transient Response Time (for the output voltage to recover to within 150 mV following any step change from 100% to
50% or 50% to 100% of the rated output current): < 900 µs

AC Line Input * (selectable - see Appendix C)

Range 1
Ac input phase-to-phase voltage: 3-phase 180-235 Vac
Ac input frequency: 47-63 Hz *
Range 2
Ac input phase-to-phase voltage: 3-phase 360-440 Vac
Ac input frequency: 47-63 Hz *
* Power source can be DELTA or WYE.
* For 47 to 53 on Range 1 only, derate output voltage linearly from 100% at 200 Vac to 95% at 180 Vac.

Notes: 1For Supplemental Characteristics, see Table 1-4b.

General Information 31
 1
Table 1-4b. Supplemental Characteristics for Series 668xA
Parameter Agilent Model Number

6680A 6681A 6682A 6683A 6684A

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Current:** rms 290 mA 190 mA 40 mA 28 mA 23 mA
**With load inductance > 5µH.

Output Programming Range (maximum programmable values)

Voltage: 5.125 V 8.190 V 21.50 V 32.8 V 41.0 V
Current: 895 A 592 A 246 A 164 A 131 A
Overvoltage Protection (OVP): 6.25 V 10.0 V 26.3 V 40.0 V 50.0 V

Typical Resolution
Voltage: 1.35 mV 2.15 mV 5.7 mV 8.6 mV 10.8 mV
Current: 235 mA 155 mA 64 mA 43 mA 34 mA
Overvoltage Protection (OVP): 30 mV 45 mV 120 mV 180 mV 225 mV

Accuracy ( @ 25 ±5 °C)*
Overvoltage Protection (OVP): 120 mV 180 mV 470 mV 720 V 900 V
Analog Programming (VP): ±0.3%± 10 mV 20 mV 50 mV 75 mV 100 mV
Analog Programming (IP):±2% ± 8A 4A 2A 1.5 A 1A
Current Monitor (IM):±2%± 8A 4A 2A 1.5 A 1A

Analog Programming (VP & IP)

Input Signal (source must be isolated)
VP Input Signal:* 0 to -5.0 V
+ IP Input Signal:** 0 to +5.0 V
Input Impedance
VP and IP Inputs: > 30 kΩ
*Referenced to common ↓P. ** Referenced to -IP differential input signal
Current Monitor (IM) Output Signal: -0.125 V to +5 V

Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,
load, and ambient temperature)
Voltage: 0.02% + 0.15 mV 0.24 mV 0.63 mV 0.96 mV 1.2 mV
Current: 0.02% + 315 mA 170 mA 71 mA 47 mA 38 mA

Temperature Coefficients (change per °C after 30-minute warmup)

Voltage: 50 ppm + 0.05 mV 0.08 mV 0.21 mV 0.32 mV 0.40 mV

Current: 75 ppm + 110 mA 62 mA 26 mA 17 mA 14 mA
Voltage Readback: 60 ppm + 0.075 mV 0.1 mV 0.25 mV 0.40 mV 0.50 mV
±Current Readback: 85 ppm + 135 mA 90 mA 37 mA 25 mA 20 mA
Overvoltage Protection (OVP):
200 ppm + 1.25 mV 1.8 mV 4.7 mV 7.2 mV 9.0 mV
Typical Common Mode Noise Current*
rms: 1.5 mA 1.5 mA 3 mA 3 mA 3 mA
peak-to-peak: 10 mA 10 mA 20 mA 20 mA 20 mA
* Referenced to signal ground binding post.

Output Float Voltage (maximum from output signal ground): ±60 Vdc
1
Notes: For Performance Specifications, see Table 1-4a.

32 General Information
 1
Table 1-4b. Supplemental Characteristics for Series 668xA (continued)
Parameter Agilent Model Number
6680A 6681A 6682A 6683A 6684A
Remote Sensing Capability
Voltage Drop Per Lead: Up to 1/2 of rated output voltage.

Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.
Load Regulation:
Degradation due to load lead drop in--output: ∆mV (regulation) = Vdrop(Rsense -)
Degradation due to load lead drop in + output:
∆mV (regulation) = Vdrop(Rsense +) + 2Vdrop(Vrating)/(Vrating + 10 V)
where Rsense _ and Rsense + are resistances of respective sense leads.

Maximum Reverse Voltage Current Sink Capability: *

With ac input power applied and the dc output reverse biased
by an external dc source, the supply will continuously
withstand without damage a current equal to its output
current rating.
* Current must be limited by user's external dc source.
Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.

Maximum Input Power: 7350 VA,

6000 W,
160 W (with no load)
Maximum AC Line Current Ratings
Range 1
Rms line current: 21.4 A (27.7 A) ***
Line fuse: 30 AM
Range 2
Rms line current: 10.7 A (14.4 A) ***
Line fuse: 16 AM
*** Includes 5% unbalanced voltage phase condition.
Output Voltage Programming Response Time**
Programming Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total
excursion):***
9 ms 12 ms 45 ms 60 ms 60 ms
Full-load programming speed up/down time (time for output to settle within 4 LSBs of the final value):***

27 ms 35 ms 140 ms 185 ms 185 ms

No-load downprogrammiug discharge time (time for output to fall to 0.5 V when programmed from full voltage to
zero volts):
90 ms 100 ms 475 ms 650 ms 575 ms
** All values exclude command processing time.
*** With full resistive load = VRATED/IRATED

Notes: lFor Performance Specifications, see Table l-4a.

General Information 33
 1
Table 1-4b. Supplemental Characteristics for Series 668xA (continued)
Parameter All Models
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply is
connected directly to the GPIB Bus): 20 ms
Monotonicity: Output is monotonic over entire rated voltage, current, and
temperature range.
Auto-Parallel Configuration: Up to 3 identical models

Nonvolatile Storage
State storage & recall locations: 4
Prestored turn-on state: Location 0
Maximum memory write cycles: 40,000, typical

Digital Port Characteristics (see Table 1-5)

GPIB Interface Capabilities (see Table 1-5)

Serial Link Capabilities (see Table 1-5)

Recommended Calibration Interval: 1 year

Safety Compliance
Complies with: CSA 22.2 No.231,
Designed to comply with: IEC 1010 (carries CE mark)
UL 1244
RFI Suppression (complies with): CISPR-ll, Group 1, Class B
Dimensions
Width: 425.5 mm (16.75 in)
Height
including removable feet 234.2 mm (9.25 in)
excluding removable feet 221.5 mm (8.75 in)
Depth (without output safety cover): 674.7 mm (25.56 in)

Weight
Net: 51.3 kg (113 lb)
Shipping: 63.6 kg (140 lb)
Output Characteristic Curve:

Notes: lFor Performance Specifications, see Table l-4a.

34 General Information
 1
Table 1-4b. Supplemental Characteristics for Series 668xA (continued)
Parameter All Models
Output Impedance Curves (Typical):
CV MODE CV MODE
CC MODE CC MODE
20 20 *
*
10 10

OUTPUT IMPEDANCE (MILLIOHMS)

5 5
OUTPUT IMPEDANCE (MILLIOHMS)

** **
2.5 2.5

1.25 1.25

0.625 0.625

0.312 0.312

0.156 0.156

0.078 0.078

0.039 0.039

0.0195 0.195
30 100 1K 10K 50K 100 50K
30 1K 10K

FREQUENCY (HZ) FREQUENCY (HZ)

Agilent 6680A Agilent 6681A

CV MODE CV MODE
CC MODE CC MODE
* *
4040 80
** **
20 40
OUTPUT IMPEDANCE (MILLIOHMS)

10
20
OUTPUT IMPEDANCE (MILLIOHMS)

5
10

2.5 5

1.25 2.5

0.625
1.25

0.312
0.625

0.156
0.312

0.0781
0.156
0.0391
0.0781
30 100 1K 10K 50K
30 100 1K 10K 50K
FREQUENCY (HZ) FREQUENCY (HZ)

Agilent 6682A Agilent 6683A

CV MODE
CC MODE
80
** *
* ALL COMPENSATION SWITCHES OPEN
** ALL COMPENSATION SWITCHES CLOSED 40

20
OUTPUT IMPEDANCE (MILLIOHMS)

10

2.5

1.25

O.625

O.312

0.156

0.0781
30 100 1K 10K 50K

FREQUENCY ( HZ )

Agilent 6684A

Notes: lFor Performance Specifications, see Table l-4a.

General Information 35
 1
Table 1-5a. Performance Specifications for Series 669xA
Parameter Agilent Model Number
6690A 6691A 6692A
Output Ratings
Voltage: 0 - 15 V 0 - 30 V 0- 60 V
Current:* 0 - 440 A 0 - 220 A 0 – 110 A
*Derated linearly 1%/°C from 40 ° C to 55 °C

Programming Accuracy (@ 25 ± 5 °C)

Voltage: 0.04% + 15 mV 30 mV 60 mV
Current: 0. l % + 230 mA 125 mA 65 mA

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Voltage: rms 2.5 mV 2.5 mV 2.5 mV
Constant Voltage: p-p 15 mV 25 mV 25 mV

Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ± 5 °C)
Voltage: 0.05% + 22.5 mV 45 mV 90 mV
±Current 0.1% + 300 mA 165 mA 80 mA

Load Regulation (change in output voltage or current for any load change within ratings)
Voltage 0.002% + 650 µV 1.1 mV 2.2 mV
Current: 0.005% + 40 mA 17 mA 9 mA

Line Regulation (change in output voltage or current for any line change within ratings)
Voltage: 0.002% + 650 µV 650 µV 650 µV
Current: 0.005% + 40.5 mA 17 mA 9 mA

Transient Response Time (for the output voltage to recover to within 150 mV following any step change from 100% to
50% or 50% to 100% of the rated output current): < 900 µs

AC Line Input * (selectable - see Appendix C)

Range 1
Ac input phase-to-phase voltage: 3-phase 180-235 Vac
Ac input frequency: 47-63 Hz *
Range 2
Ac input phase-to-phase voltage: 3-phase 360-440 Vac
Ac input frequency: 47-63 Hz *
* Power source can be DELTA or WYE.

Notes: 1For Supplemental Characteristics, see Table 1-5b.

36 General Information
 1
Table 1-5b. Supplemental Characteristics for Series 669xA
Parameter Agilent Model Number

6690A 6691A 6692A

Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)
Constant Current:** rms 200 mA 50 mA 30 mA
**With load inductance > 5µH.

Output Programming Range (maximum programmable values)

-Max Power 6.67KW
Voltage: 15.375 V 30.75 V 61.5 V
Current: 450 A 225 A 112 A
Overvoltage Protection (OVP): 18 V 36 V 69 V

Typical Resolution
Voltage: 4.1 mV 8.1 mV 16 mV
Current: 118.5 mA 59 mA 30 mA
Overvoltage Protection (OVP): 90 mV 170 mV 330 mV

Accuracy ( @ 25 ±5 °C)*
Overvoltage Protection (OVP): 350 mV 675 mV 1.3 V
Analog Programming (VP): 0.3% + 40 mV 75 mV 150 mV
Analog Programming (IP): 2% + 3A 2A 1A
Current Monitor (IM): 2% + 3A 2A 1A

Analog Programming (VP & IP)

Input Signal (source must be isolated)
VP Input Signal:* 0 to -5.0 V
+ IP Input Signal:** 0 to +5.0 V
Input Impedance
VP and IP Inputs: > 30 kΩ
*Referenced to common ↓P. ** Referenced to -IP differential input signal
Current Monitor (IM) Output Signal: -0.125 V to +5 V

Drift Temperature Stability

(following a 30-minute warmup, change in output over eight hours under constant line, load, and ambient temperature)
Voltage: 0.02% + 0.45 mV 0.90 mV 1.8 mV
Current: 0.02% + 130 mA 65 mA 33 mA

Temperature Coefficients (change per °C after 30-minute warmup)

Voltage: 50 ppm + 0.30 mV 0.30 mV 0.60 mV
Current: 75 ppm + 48 mA 24 mA 12 mA
Voltage Readback: 60 ppm + 0.20 mV 0.4 mV 0.75 mV
±Current Readback: 85 ppm + 70.5 mA 40 mA 17 mA
Overvoltage Protection (OVP):
200 ppm + 3.6 mV 6.5 mV 13 mV
Typical Common Mode Noise Current*
rms: 3 mA 3.5 mA 4 mA
peak-to-peak: 20 mA 20 mA 25 mA
* From 20Hz to 2MHz; Referenced to signal ground binding post.

Output Float Voltage (maximum from output signal ground): ±60 Vdc
1
Notes: For Performance Specifications, see Table 1-5a.

General Information 37
 1
Table 1-5b. Supplemental Characteristics for Series 669xA (continued)
Parameter Agilent Model Number
6690A 6691A 6692A
Remote Sensing Capability
Voltage Drop Per Lead: Up to 1/2 of rated output voltage.

Load Voltage: Subtract voltage drop in load leads from specified output
voltage rating.
Load Regulation:
Degradation due to load lead drop in--output: ∆mV (regulation) = Vdrop(Rsense -)
Degradation due to load lead drop in + output:
∆mV (regulation) = Vdrop(Rsense +) + 2Vdrop(Vrating)/(Vrating + 10 V)
where Rsense _ and Rsense + are resistances of respective sense leads.

Maximum Reverse Voltage Current Sink Capability: *

With ac input power applied and the dc output reverse biased
by an external dc source, the supply will continuously
withstand without damage a current equal to its output
current rating.
* Current must be limited by user's external dc source.
Maximum Input Power: 9000 VA,
7950 W,
175 W (with no load)
Maximum AC Line Current Ratings
Range 1
Rms line current: 26 A ***
Line fuse: 40 AM
Range 2
Rms line current: 13 A***
Line fuse: 20 AM

Output Voltage Programming Response Time**

Programming Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total
excursion):***
45 ms 60 ms 100 ms
Full-load programming speed up/down time (time for output to settle within 4 LSBs of the final value):***

150 ms 185 ms 280 ms

No-load downprogrammiug discharge time (time for output to fall to 0.5 V when programmed from full voltage
to zero volts):
340 ms 650 ms 870 ms
** All values exclude command processing time.
*** With full resistive load = VRATED/IRATED

Notes: lFor Performance Specifications, see Table l-5a.

38 General Information
 1
Table 1-5b. Supplemental Characteristics for Series 669xA (continued)
Parameter All Models
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply is
connected directly to the GPIB Bus): 20 ms
Monotonicity: Output is monotonic over entire rated voltage, current, and
temperature range.
Auto-Parallel Configuration: Up to 3 identical models

Nonvolatile Storage
State storage & recall locations: 4
Prestored turn-on state: Location 0
Maximum memory write cycles: 40,000, typical

Digital Port Characteristics (see Table 1-6)

GPIB Interface Capabilities (see Table 1-6)

Serial Link Capabilities (see Table 1-6)

Recommended Calibration Interval: 1 year

Safety Compliance
Complies with: CSA 22.2 No.231,
Designed to comply with: IEC 1010 (carries CE mark)
UL 1244
RFI Suppression (complies with): CISPR-ll, Group 1, Class B
Dimensions
Width: 425.5 mm (16.75 in)
Height
including removable feet 234.2 mm (9.25 in)
excluding removable feet 221.5 mm (8.75 in)
Depth (without output safety cover): 674.7 mm (25.56 in)

Weight
Net: 51.3 kg (113 lb)
Shipping: 63.6 kg (140 lb)
Output Characteristic Curve:
Output Characteristic Curve:

Vout CV operating
line Maximun Rated Output
Vmax
Agilent
Vout Iout
Vset Model

1 6690A 15V 440A

2

6691A 30V 220A

CC operating line

0 6692A 60V 110A

Iout
Iset Imax

Notes: lFor Performance Specifications, see Table l-4a.

General Information 39
 1
Table 1-5b. Supplemental Characteristics for Series 669xA (continued)
Parameter All Models
Output Impedance Curves (Typical):
CC mode
CV mode
Agilent 6690A 1000

*
100

Magnitude (in milliohms)

**
10

0.1

0.01
10 100 1000 10000 100000
Frequency (in Hz)
CC mode
CV mode
Agilent 6691A 1000

*
100
Magnitude (in milliohms)

**
10

0.1

0.01
10 100 1000 10000 100000
Frequency (in Hz)
CC mode
CV mode
Agilent 6692A 1000 *

**
100
Magnitude (in milliohms)

10

1
* All compensation switches open
** All compensation switches closed

0.1
10 100 1000 10000 100000
Frequency (in Hz)

Notes: lFor Performance Specifications, see Table l-4a.

40 General Information
 -
Table 1-6. Supplemental GPIB Characteristics for All Models
Parameter All Models

Digital Port Characteristics

Maximum ratings: 16.5 Vdc between terminals 1 & 2; 3 & 4; and from 1 or 2 to
chassis ground
FLT/INH Operation
FLT/INH Terminals 1 & 2
Iol (low-level output current) 1.25 mA maximum
Vol (low-level output voltage) 0.5 V maximum
FLT/INH Terminals 3 & 4
Vil (low-level input voltage) 0.8 V maximum
Vih (high-level input voltage) 2.0 V minimum
Iil (low-level input current) 1 mA
tw (pulse width) 100 µs, minimum
td (time delay) 4 ms, typical

Digital I/O Operation

Digital OUT Port 0,1,2 - Open Collector:
Ioh (high-level output leakage @ 16.5 V) 100 µA (ports 0,1); 12.5 mA (port 2)
Ioh (high-level output leakage @ 5.25 V) 100 µA (ports 0,1); 250 µA (port 2)
Iol (low-level output sink current @ 0.5 V) 4 mA
Iol (low-level output sink current @ l V) 250 mA

Digital IN Port 2 - Internal 4.64 k Pullup:

Iil (low-level input current @ 0.4 V) 1.25 mA
Iih (high-level input current @ 5.25 V) 250 µA
Vil (low-level input voltage) 0.8 V maximum
Vih (high-level input voltage) 2.0 V minimum

GPIB Interface Capabilities

Languages: SCPI (default); Compatibility
Interface: AH1, C0, DC1, DT1, E1, LE4, PP0, RL1, SH1, SR1, TE6

Serial Link Capabilities (multiple supplies sharing one GPIB primary address)
Maximum number of supplies: 16
Maximum number of linked supplies: 15
Maximum total chain cable length: 30 m (100 ft)

Table 1-7. Operator Replaceable Parts List

Description Agilent Part No.
(Unless otherwise specified, parts apply to all models.)

Cable assembly, GPIB (See “Accessories”)

Cable assembly, serial link (See “Accessories”)
Collar, rotary output control 5040-l700
Cover, ac input safety
Series 667xA, w/strain relief connector & rubber boot 5040-1676
Series 668xA, w/strain relief connector & rubber boot 5060-3237
Series 669xA, w/strain relief connector & rubber boot 5002-1592
Cover, dc output
Series 664xA and 665xA 0360-2191
Series 667xA 5040-1674
Series 668xA 5040-1692
Series 669xA 5040-1692

General Information 41
 Table 1-7. Operator Replaceable Parts List (continued)
Description Agilent Part No.
(Unless otherwise specified, parts apply to all models.)
Flatwasher, ac input safety cover (Series 667xA, 668xA) 3050-1053
Foot, cabinet 5041-8801
Fuse, power
Series 664xA
100 Vac line voltage, 6 AM 2110-0056
120 Vac line voltage, 5 AM 2110-0010
220/230/240 Vac line voltage, 3 AM 2l10-0003
Series 665xA
100 Vac line voltage, 15 AM 2110-0054
120 Vac line voltage, 12 AM 2110-0249
220/230/240 Vac line voltage, 7 AM 21l0-06l4
Series 667xA*
*This is an internal fuse not replaceable by the operator.
Series 668xA
16 AM for 360-440 Vac line (set of 3) 5060-3512
30 AM for 180-235 Vac line (set of 3) 5060-3513
Series 669xA
20 AM for 360-440 Vac line (set of 3) 5065-6935
40 AM for 180-235 Vac line (set of 3) 5065-6934
Knob, rotary output control 0370-1091
Lockwasher, ac input safety cover (Series 667xA and 668xA) 2190-0484
Lockwasher, output bus bar, 1/4 spring (Series 667xA only) 3050-1690
Manual
Agilent 59510A/11 Relay Accessories 5957-6382
Series 603xA Operating 5959-3301
Series 664xA and 665xA Service 5959-3376
Series 664xA, 665xA, 667xA, 668xA, and 669xA Programming Guide 5964-8269
Series 667xA Service 5959-3384
Nut, output bus bar, hex 1/4-20x1/2 (Series 667xA) 2950-0084
Nut, power ground, hex w/lw 3/8x32 (Series 667xA) 0590-0305
Nut, power input cable (Series 668xA) 0535-0082
Nut, power input cable (Series 669xA) 0535-0038
Plug, analog connector 1252-3698
Plug, digital connector 1252-1488
Power cord assembly (See "Options" )
Rack mount kit (See "Options")
Resistor, calibration (See Appendix A)
Screw, ac input safety cover, M4.0 x 60 mm long (Series 667xA, 668xA) 0515-0156
Screw, ac input safety cover, M4.0 x 60 mm long (Series 669xA) 0515-0380
Screw, carrying strap, M5x0.8x10 mm 0515-1384
Screw, dc output cover (Series 664xA and 665xA) 0360-219l
Screw, output bus bar
Series 665xA 0515-1085
Series 667xA, 1/4-20x1/2 2940-0103
Screw, outer cover, M5 x 0.8 mm 0515-0073
Screw, output sense terminal, M3x0.5x8mm (Series 667xA, 668xA, 669xA) 0515-0104
Slide mount kit ( “See Accessories” )
Standoff, GPIB 0380-0643
Terminal, crimp, ac power cord (Series 667xA only)
L or N terminal 0362-0681
Gnd terminal 0362-0207

42 General Information
 2
Installation

Inspection

Damage

When you receive your power supply, inspect it for any obvious damage that may have occurred during shipment. If there is
damage, notify the shipping carrier and the nearest Agilent Sales and Support Office immediately. Warranty information is
printed in the front of this guide.

Packaging Material

Until you have checked out the power supply save the shipping carton and packing materials in case the power supply has to
be returned to Agilent Technologies. If you return the power supply for service, attach a tag identifying the model number
and the owner. Also include a brief description of the problem.

Items Supplied

In addition to this manual, check that the following items in Table 2-1 are included with your power supply (see Table 1-6
for part numbers):

Table 2-1. Items Supplied

Power cord Series 664xA and 665xA
Your power supply was shipped with a power cord for the type of outlet specified for your location. If
the appropriate cord was not included, contact your nearest Agilent Sales and Support Offices (see end
of this guide) to obtain the correct cord. Caution: Your power supply cannot use a standard power cord.
The power cords supplied by Agilent Technologies have heavier gauge wire.

Series 667xA, 668xA, 669xA

Your power supply was shipped with a power cord appropriate for your location. The cord may or may
not be terminated in a power plug (see "Options" in Chapter 1). If the cord is not included, contact your
nearest Agilent Sales and Support Office (see end of this guide ) to obtain the correct cord. These
models also include a power input safety cover with strain relief connector. It is required to secure the
power cord to the power supply.

Analog A 7-terminal analog plug (see Table 1-6) that connects to the back of the supply. Analog connections are
connector described in Chapter 4.

Digital A 4-terminal digital plug (see Table 1-6) that connects to the back of the supply. Digital connections are
connector described in "Appendix D - Digital Port Functions"

Serial cable A 2-meter cable (see “Accessories” in Chapter 1) that connects to the control bus (next to the GPIB
connector). This cable is used to serially connect multiple supplies as described under "Controller
Connections" in Chapter 4.

Installation 43
 Table 2-1. Items Supplied (continued)
Output Series 667xA only
hardware Output hardware (screws with nuts and lockwashers) for securing your load wires to the output bus bars
(see Table 1-6).

Guide change If applicable, change sheets may be included with this guide. If there are change sheets, make the
page indicated corrections in this guide.

Cleaning
To prevent electric shock, unplug the unit before cleaning.
Use a dry cloth or one slightly dampened with water to clean the external case parts. Do not attempt to clean internally.

Location and Temperature

Bench Operation

The “Supplemental Characteristics” in Chapter 1 give the dimensions of your power supply. The cabinet has plastic feet that
are shaped to ensure self-alignment when stacked with other Agilent System II cabinets. The feet may be removed for rack
mounting. Your power supply must be installed in a location that allows sufficient space at the sides and rear of the cabinet
for adequate air circulation. Minimum clearances are 1 inch (25 mm) along the sides. Do not block the fan exhaust at the
rear of the supply.

Rack Mounting

Series 668xA and 669xA supplies weigh 51.3 kg (113 lb). Obtain adequate help when mounting the
supply in the rack.

The power supply can be mounted in a standard l9-inch rack panel or cabinet. Rack mounting kits are available as Option
908 or 909 (with handles). Installation instructions are included with each rack mounting kit.

Series 667xA, 668xA, &669xA

Series 667xA, 668xA, 669xA supplies require instrument support rails for non-stationary installations.
These are normally ordered with the cabinet and are not included with the rack mounting kits.

Temperature Performance

A variable-speed fan cools the supply by drawing air through the sides and exhausting it out the back. Using Agilent rack
mount or slides will not impede the flow of air. The temperature performance is as follows:

Series 664xA & 665xA Operates without loss of performance within the temperature range of 0 °C to 40 °C and with
derated output from 40 °C to 55 °C.

Series 667xA, 668xA, &669xA Operates without loss of performance within the temperature range of 0 °C to 55 °C.

It a Series 664xA or 665xA power supply is operated at full output current for several hours, the sheet
metal immediately under the transformer (near the right front) can get very hot. Do not touch this area of
the cabinet. The line cord also can become quite warm. Both of these conditions are normal.

44 Installation
Input Power Source
Refer to the applicable paragraphs below for information on the input power source. Do not apply power to the power
supply until directed to do so in Chapter 3.

Check the line RATING label on the rear of your supply and verify that the voltage shown there
corresponds to the nominal line voltage of your power source. If it does not, see "Appendix C - Line
Voltage Conversion" for instructions on changing the power supply's line voltage configuration.

Installing the Series 664xA and 665xA Power Cord

The supplied cord connects to the power receptacle on the rear panel ( 2, Figure 2-l).

n You can operate your supply from a nominal l00 V, 120 V, 220 V, 230 V, or 240 V single-phase ac power source as
indicated on the rear panel line RATING label 1.
n See "AC Input Ratings" in Table l-la or Table 1-2a for the voltage and frequency range for each type of power source.
"Maximum AC Line Current Ratings" in Table l-lb or Table 1-2b show the maximum load current.
n The line fuse is located in a fuseholder on the rear panel 3. The rear panel label 1 shows the fuse value used in the
power supply and Table 1-6 identifies the replacement fuse.

Figure 2-1. Series 664xA and 665xA Power Connection

Installing the Series 667xA Power Cord

Note This product requires single-phase input voltage.

You can operate your supply from a nominal 200 V or 230 V, single-phase power source, or from the line-to-line voltage of
a 208-volt, 3-phase source. The proper source is indicated on the rear line RATING label ( 4, Figure 2-2). See "AC Input
Ratings" in Table 1-3a for the voltage and frequency range for each type of power source.

Note The power source must be a dedicated line with no other devices drawing current from it.

The line fuse is located inside the power supply. Table 1-6 identifies the replacement fuse. See "In Case of Trouble" in
Chapter 3 for instructions on fuse replacement.

Installation of the power cord must be done by a qualified electrician and in accordance with local
electrical codes.

Installation 45
The power cord supplied with power supply may or may not include a power plug (see "Options" in Chapter l) at one end of
the cord. Terminating connections and a ground lug are attached to the other end of the cord.

See Figure 2-2 and proceed as follows:

1. If they are not already in place, position the strain relief connector ), safety cover , rubber boot , and connector
nut on the power cord .
2. Secure the ground wire to the chassis earth ground stud.
3. For single-phase operation, connect the neutral wire to the N input terminal and the line wire to the L input
terminal (this line is fused inside the supply).
4. For line-to-line operation from a three-phase source as shown in Figure 2-3, connect one phase to the N input terminal
and another phase to the L input terminal (this line is fused inside the supply).

Note The N terminal is not internally grounded.

5. Position the safety cover over the power input terminals and tighten the cover screws and strain relief connector
screws .

Figure 2-2. Connecting the Series 667xA Power Cord

Figure 2-3. 667xA Connection to a 3-Phase Line

46 Installation
Installing the Series 668xA Power Cord
The Series 668xA power supply requires a 3-phase power source that provides 7350 VA (6000 W) maximum. The supply
has a delta input (no neutral connection) and will accept power from either delta (triangle) or wye (star) sources. Two
voltage ranges are available (see "AC Input Ratings" in Table 1-4a). In order to maintain phase current balancing, the
power source should be a dedicated line with only Agilent Technologies Series 668xA/669xA supplies drawing current from
it. A disconnect box located near the power supply (see Figure 2-4) is recommended for all installations and is mandatory
for direct-wired installations.

• 3-phase Mains (delta or wye)

‚ AC Safety Disconnect (required for direct-wired installations
ƒ Series 668xA/669xA Power Supply

Figure 2-4. Series 668xA/669xA Overall Wiring Diagram.

Installation of the power cord must be done by a qualified electrician and in accordance with local
electrical code.

The power cords supplied with the power supply do not include a power plug (see "Options" in Chapter l) at one end of the
cord. Terminating connectors and a ground lug are attached to the other end of the cord.

See Figure 2-5 and proceed as follows:

l. Check the line fuses ( , Figure 2-5) as follows:
a. Examine the LINE RATING label on the rear panel.
b. Unscrew the line fuse caps ( from the rear panel and verify that all fuses are as specified on the label. Replace the
fuses.
2. Open the line clamp and insert the line cord through the opening.
3. Position the line cord so that the clamp is near the end of the outside insulating sheath. Tighten the screws securing
the clamp.
4. Secure the three ac lines to the ac power strip as follows:
* Phase 1 to L1. Phase 2 to L2. Phase 3 to L3.
5. Secure the ground wire to the chassis earth ground stud.

Do not connect anything to the terminal marked "DO NOT USE".

6. Slip the safety cover over the fuses and terminal strip and secure the cover with the four capscrews.
7. If required, wire the appropriate power plug to the other end of the power cord.

Note For user-made cable , strip back sheath 100 mm (3.9 in).

Installation 47
 Figure 2-5. Connecting the Series 668xA Power Cord

Installing the Series 669xA Power Cord

The Series 669xA power supply requires a 3-phase power source that provides 9000 VA (7950 W) maximum. The supply
has a delta input (no neutral connection) and will accept power from either delta (triangle) or wye (star) sources. Two
voltage ranges are available (see "AC Input Ratings" in Table 1-4a). In order to maintain phase current balancing, the
power source should be a dedicated line with only Agilent Technologies Series 668xA/669xA supplies drawing current from
it. A disconnect box located near the power supply (see Figure 2-4) is recommended for all installations and is mandatory
for direct-wired installations.

Installation of the power cord must be done by a qualified electrician and in accordance with local
electrical code.

The power cords supplied with the power supply do not include a power plug (see "Options" in Chapter l) at one end of the
cord. Wires are partially stripped back and a ground lug is attached to the other end of the cord.

See Figure 2-6 and proceed as follows:

l. Check the line fuses ( , Figure 2-6) as follows:
a. Examine the LINE RATING label on the rear panel to make sure the correct voltage and fuses are indicated.
b. Pull back on the lever located on each fuseholder and verify that all fuses are as specified on the label.
c. Make sure that the fuse indicator pin located in the center of the fuse is facing OUT, not IN
d. Close the fuseholder.
e. Check to make sure that the red flag does not appear in the fuse holder window after you close the fuseholder .

When installing the fuses, make sure that the fuse indicator pin located in the center of the fuse is facing
OUT, not IN.

2. Open the line clamp . Position the insulating sheath over the end of the line cord. where it passes through the
cable clamp. Insert the through the cable clamp making sure that the sheath is between the cord and the cable clamp.
3. Tighten the screws securing the clamp .

48 Installation
4. Insert the line cord with the cable clamp into one of the two openings on the safety cover. (The illustration shows the line
cord istalled in the bottom opening.) Tighten the cable clamp to the safety cover.
5. Remove the insulation from the pre-striped end of the three ac lines. Secure the lines in the top of each fuse holder as
follows:
Phase 1 to L1. Phase 2 to L2. Phase 3 to L3.
6. Secure the ground wire to the chassis earth ground stud.
7. Position the safety cover over the fuses and secure the cover with the four cover screws.
8. Place the metal cap into the opening of the safety cover that is not being used by the line cord.
9. Wire the appropriate power plug to the other end of the power cord.

Note For user-provided cable, remember to position the insulating sheath over the end of the wires where
they pass through the cable clamp.

LINE RATING DIG CNTL J1 J2

1 7

6
INTERNAL FUSES WARNING:
For continued protection against
fire hazard replace fuse with the
same type and rating. 5
L1 L2 L3 FUSES
UNDER
COVER

4
FUSES BLOWN
WHEN RED FLAG

3 IS IN WINDOW

10 11

Figure 2-6. Connecting the Series 669xA Power Cord

Installation 49
 3
Turn-On Checkout

Note This chapter provides a preliminary introduction to the power supply front panel. See "Chapter 5 - Front
Panel" for more details.

Introduction
Successful tests in this chapter provide a high degree of confidence that the power supply is operating properly. For
verification tests, see “Appendix B - Operation Verification”. Complete performance tests are given in the service manual
(see Table 1-5 in Chapter 1). Do not apply ac power to the power supply until told to do so.

Preliminary Checkout (All Models)

1. Make certain that the front panel switch is off.

2. Examine the Line Voltage Rating or Line And Fuse Rating label (see "Chapter 2 - Installation" )
a. Verify that the line voltage rating agrees with your power source. If it does not, see "Appendix C - Line Voltage
Conversion".
b. Series 664xA/665xA - Use a screwdriver to remove the line fuse from the fuseholder (3, Figure 2-1). Verify that the
fuse is as specified on the label. Replace the fuse.
c. Series 668xA - Unscrew the fuse caps from the rear panel (2, Figure 2-4). Verify that the fuse is as specified on the
label. Replace the fuse.
d. Series 669xA - Flip open the fuseholder located under the ac line safety cover on the rear panel. Verify that the fuse
is as specified on the label. Replace the fuse.

3. Check the sense wiring as follows:

a. Series 664xA/665xA - The SENSE switch (4, Figure 4-3a) is set to Local.
b. Series 667xA - Remove the output safety cover (1, Figure 4-4a) and examine the output sense terminals (4 and 5).
They should be wired for local sensing as follows:
1. The +LS sense terminal wired to the +S terminal of the analog connector (2).
2. The -LS sense terminal wired to the -S terminal of the analog connector.
3. If the power supply is not wired for local sensing, make the above connections, using small-capacity wire (#22 is
sufficient).
c. Series 668xA/669xA - Examine the output bus bars (Figure 4-5a) and make sure they are connected for local
sensing as follows:
1. The + bar is wired to the +S terminal of the analog connector.
2. The - bar is wired to the -S terminal of the analog connector.
3. If the power supply is not wired for local sensing, make the above connections, using small-capacity wire (#22 is
sufficient).

4. Make sure that there is no load connected to the output terminals or bus bars.

Turn-On Checkout 51
Power-On Checkout (All Models)
1. Connect the power cord to the power source (for Series 668xA & 669xA, turn on the safety disconnect switch).
2. Turn the front panel power switch to ON (1).
3. The power supply undergoes a self-test when you turn it on. If the test is normal, the following sequence appears on the
LCD:
a. Series 664xA/665xA - The GPIB address (factory default is 5).
b. Series 667xA/668xA/669xA - The GPIB address (factory default is 5). This is then followed by PWR ON INIT
for approximately 10 seconds.
4. The display then goes into the meter mode with the Dis annunciator on and all others off. “Meter mode” means that the
VOLTS digits indicate the output voltage and the AMPS digits indicate the output current. These values will be at or
near zero.
5. Verify that the power supply fan is on by placing your hand near the rear grill to feel the air flow. You may also be able to
hear the fan operating.
6. Press once. The Dis annunciator will go off and the CV annunciator will go on .

Note If the power supply detects an error during self-test, the display will show an error message. Go to “In
Case of Trouble” at the end of this chapter.

Using the Keypad (All Models)

Shifted Keys
Some of the front panel keys perform two functions, one labeled in black and the other in blue. You access the blue function
by first pressing the blue key, which is not labeled. When the Shift annunciator is on, you will know you have access
to the key's shifted (blue) function.

Backspace Key
The key is an erase key. If you make a mistake entering a number and have not yet entered it (have not pressed
), you can delete the number by pressing . You may delete as many numbers as you wish by repeatedly pressing
this key.

Output Checkout (All Models)

Important When the power supply is turned on, it asserts the state stored in EEPROM memory location 0.
For a new supply, this is the factory default (*RST) state. The following procedures assume that the
factory default state is still in location 0 (Turn-On Conditions in “Chapter 5 - Front Panel” for details).

52 Turn-On Checkout
Checking the Voltage Function
The tests in Table 3-1 check the basic voltage functions with no load connected to the power supply. The VOLTS display
will show various readings. Ignore the AMPS display.

Table 3-1. Checking the Voltage Functions (Output Terminals Open)

Procedure Display Explanation
Output Terminals Open or Connected to a Voltmeter
If Dis is on, turn it off by pressing
Press key VOLT 0.000 Default voltage setting. CV annunciator should be on. (If CC annunicator
is on, increase the current by pressing one or more times until
CC turns off and CV turns on.)

Press VOLT 4 Program output to 4 volts.

Press 4.000 Enter the voltage. Meter mode displays output voltage. During these
tests, there may be a small (relative to full output) AMPS reading that
will be ignored.

Press several Voltage decreases several millivolts each time you press the key.*
times

Press the same Voltage increases several millivolts each time you press the key.*
number of times

* The number of millivolts change is determined by the voltage programming resolution of

your power supply (see "Supplemental Characteristics" in Chapter 1).
Rotate Voltage control first Control operates similarly to and keys. The control
counterclockwise and then is rate sensitive. Turning it more quickly causes a more rapid change in
clockwise voltage.

Press 4.000 Program output to 4 volts.

Press Display shows default OVP (overvoltage protection) trip voltage for your
supply (see "Supplemental Characteristics" in Chapter 1).

Press OV 3 Program the OVP to 3 volts, which is less than the output voltage.

Press 0.000 OVP voltage entered is less than the output voltage. This causes the OVP
circuit to trip. The output drops to zero, CV turns off, and Prot turns on.

Press OV - - - - - Shows that the power supply shuts down because the OVP circuit has
tripped.

Press Return display to meter mode (optional step).

Press 0.000 Program the OVP to 4.5 volts, which is greater than the output voltage.
Note: You cannot clear an OVP trip until you have first removed the
cause of the condition.

Press Prot Clear 4.000 The OVP circuit is cleared, restoring the output. Prot turns off and CV
( )* turns on.

* is the unlabeled blue key.

Turn-On Checkout 53
Checking the Current Function

ENERGY HAZARD. Some supplies (Series 668xA/669xA) can provide more than 240 VA at more
than 2 V. If the output connections touch, severe arcing may occur resulting in burns, ignition or
welding of parts. Do not attempt to make connections while the output is live.

The tests in Table 3-2 check the basic current functions with a short connected across the power supply output. Do not
program maximum output currents unless the shorting wire is capable of handling the current (see "Supplemental
Characteristics" and Table 4-2). The AMPS display will show various readings. Ignore the VOLTS display.

Table 3-2. Checking the Current Functions (Output Terminals Shorted)

Action Display Explanation

Turn off the power supply and connect a #14 AWG or larger wire across the output (+) and (-) terminals. If you intend to
test at full-rated output current, use a wire or wires of sufficient size to carry the maximum current of the supply
(see "Supplemental Characteristics" in Chapter l and Table 4-2 in Chapter 4).

Turn on the supply. Meter mode Essentially zero outputs with Dis annunciator on.
Set the voltage to its maximum
value. This example assumes that
you have an 8-volt supply (see
"Performance Specifications" in
Chapter 1 for the value for your
specific supply) .

Press VOLT 8.000 Program output to 8 volts.

Press AMPS 1.000 Program output to 1 ampere.

CAUTION: Be certain to observe this step with Series 668xA/669xA supplies. Start at
1 ampere before going to greater output currents.

Press AMPS 1. 000 Dis annunciator turns off, CC annunciator turns on, and AMPS
display shows the programmed current.
Press several times *Current decreases several milliamperes each time you press the
key.:
Press the same *Current increases several milliamperes each time you press the
number of times key.

*The number of milliamperes is determined by the current programming resolution of

the power supply (see "Supplemental Characteristics" in Chapter 1).

Rotate the Current control first Control operates similarly to the and keys.
counterclockwise and then The control is rate sensitive. Turning it more quickly causes a
clockwise more rapid change in current.

Press You have enabled the overcurrent protection circuit. The circuit
then tripped because of the output short. The CC annunciator
turns off and the OCP and Prot annunciators come on. The
output current is near zero.

54 Turn-On Checkout
 Table 3-2. Checking the Current Functions (Output Terminals Shorted) (continued)
Action Display Explanation

Press AMPS 0.000 Dis annunciator turns on.

Press You have disabled the overcurrent protection circuit. The OCP
annunciator turns off.

Press You have cleared the overcurrent protection circuit. The Prot
( )** annunciator turns off.

Press AMPS 1.000 Dis turns off and CC turns on. The output current is restored.

If you have a shorting wire of sufficient capacity, you may continue testing up to the maximum rated current of the power
supply (see "Performance Specifications"). When finished, go to the next step.

Press AMPS 0.000 Dis turns on and output current drops to zero.

Turn off the power supply and remove the short from the output terminals.

** is the unlabeled blue key.

Checking the Save and Recall Functions (All Models)

The Series 668xA/669xA supplies have four nonvolatile memory storage locations (0 through 3). The supplies of all other
series have five (locations 0 through 4). Proceed as follows:
n Make certain that the output is on (Dis annunciator is off).
n Set the voltage output to 5 by pressing .
n Save this value to location 1 by pressing .
n Return the output voltage to 0 by pressing (This step is based on the fact that a newly shipped power
supply has the *RST parameters stored in location 0 (see "Chapter 5 - Front Panel" for more information).
n Press and notice that the output voltage returns to the value stored in location 1.

Determining the GPIB Address (All Models)

When the power supply is turned on, the display shows ADDR n, where n is the power supply GPIB address. Any time you
want to see the address, press .

The display will indicate ADDR 5, which is the factory default. If the address has been changed, then a different number
will appear (see “Setting the GPIB Address” in “Chapter 5 - Front Panel”).

In Case of Trouble

Line Fuse
If the power supply appears "dead" with a blank display and the fan not running, first check your power source to be certain
line voltage is being supplied to the power supply. If the source is normal, the power supply line fuse may be defective. On

Turn-On Checkout 55
Series 669xA supplies, if the Red indicator appears in the fuse window on the rear panel, then one or more of the line
fuses are open. If the supply has a defective fuse, replace it only once. If it fails again, investigate the reason for the failure.
Proceed as follows:

Series 664xA and 665xA Supplies

The line fuse is located on the rear panel (3, Figure 2-l). Proceed as follows:

1. Turn off the front panel power switch.

2. Using a screwdriver, remove the fuse from the fuseholder. Replace it with one of the same type (see Table 1-5 in Chapter
l). Do not use a time-delay type fuse.
3. Turn on the power supply and check the operation.

Series 667xA Supplies

Hazardous voltage can remain inside the power supply even after it has been turned off. Fuse
replacement should be done only by qualified electronics personnel.

The line fuse is located inside the power supply. To change it, proceed as follows:

l. Turn off the front panel power switch and unplug the line cord from the power source.
2. Remove the power supply dustcover as follows:
a. Remove the four screws securing the carrying straps and dustcover.
b. Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.
c. Slide the dustcover back far enough to expose the line fuse (l, Figure 3-l).
3. Observe the input rail LED under the RFI shield (4, Figure C-3 in "Appendix C - Line Voltage Conversion"). If the LED
is on, there is still hazardous voltage inside the supply. Wait until the LED goes out (this may take several minutes)
before proceeding.
4. Connect a dc voltmeter across test points TPl and TP2 (Figure C-3). It may be necessary to remove the RFI shield in
order to reach these test points. (The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts
or less, it is safe to work inside the power supply.
5. Replace the fuse with one of the same type (see Table 1-5 in Chapter l). Do not use a time-delay type fuse.
6. If you removed it in step b, be sure to replace the RFI shield.
7. Replace the dustcover.
8. Connect the line cord to the power source.
9. Turn on the front panel power switch and check the operation.

• Power Fuse ‚ Line Filter ƒ Rear of Power Supply

Figure 3-1. Series 667xA Line Fuse

56 Turn-On Checkout
Series 668xA Supplies
The line fuses are located on the rear panel (see Figure 2-5). Proceed as follows:
l. Turn off the front panel power switch and remove the input power (unplug the power cord or open the safety disconnect).
2. Remove the ac input safety cover from the rear panel.
3. Unscrew the fuse caps and remove the fuses.
4. If one or two fuses are defective, replace all three with fuses of the same type (see Table 1-5 in Chapter l).
5. Turn on the power supply and check the operation. If it is normal, replace the ac input safety cover.

Series 669xA Supplies

The line fuses are located on the rear panel (see Figure 2-6). Check the fuse indicator window on the rear of the ac input
safety cover. If the RED indicator is visible in the window, proceed as follows:
l. Turn off the front panel power switch and remove the input power (unplug the power cord or open the safety disconnect).
2. Remove the ac input safety cover from the rear panel.
3. Flip the fuseholder levers down and check the fuses. If a fuse has blown, the indicator pin will extend out of the center of
the fuse body (see Figure 2-5)
4. If one or two fuses are defective, replace all three with fuses of the same type (see Table 1-5 in Chapter l). If all three
fuses are blown, the power supply probably has a defect that requires service.

Note: When installing the fuses, make sure that the fuse indicator pin located in the center of the fuse is facing
OUT, not IN.
5. Replace the ac input safety cover.
6. Turn on the power supply and check the operation.

Maintenance Note It is recommended that new line fuses be installed every four years.

Error Messages (All Models)

Power supply failure may occur during power-on selftest or during operation. In either case, the display may show an error
message that indicates the reason for the failure.

Selftest Errors
When a selftest error occurs, it prevents all front panel operation. The display may show either a power-on error message or
a checksum error message.

Power-On Error Messages

Power-on messages appear as:
En- - - - - -
Where "n" is a number listed in Table 3-3. If this occurs, turn the power off and then back on to see if the error persists. It is
possible to recover from the EE CHKSUM error (see "Checksum Errors"). If any other message persists, the power supply
requires service.

Turn-On Checkout 57
 Table 3-3. Power-On Selftest Errors
Error Display Failed Test Error Display Failed Test
No. No.
El FP RAM Front Panel RAM E8 SEC RAM Secondary RAM
E2 FP ROM Front Panel ROM checksum E9 SEC ROM Secondary ROM checksum
E3 EE CHKSUM EEPROM E10 SEC 5V Secondary 5 V ADC reading
E4 PRI XRAM Primary external RAM Ell TEMP Secondary ambient
E5 PRI IRAM Primary internal RAM thermistor reading
E6 PRI ROM Primary ROM checksum E12 DACS Secondary VDAC/IDAC
E7 GPIB GPIB R/W to serial poll readback

Checksum Errors.

If the display shows EE CHKSUM, the power supply has detected an EEPROM checksum error. A checksum error can
occur due to the following conditions:

n Excessive number of write cycles to an EEPROM (see "Nonvolatile Memory Write Cycles" in "Supplemental
Characteristics" tables). This condition, which would appear only after extended use, is not recoverable and requires
service.
n Loss of ac input power during a checksum calculation. This condition, which is very unlikely, is recoverable.

You may be able to recover from a checksum error by writing to the EEPROM while the power supply is in the calibration
mode. To do this, proceed as follows:

1. Enable the calibration mode by pressing .

2. PASWD will appear on the display.
3. Press the number keys corresponding to the password, followed by . The Cal annunciator will go on.

Note On new equipment, the calibration password corresponds to the four-digit model number (such as
). See "Appendix A - Calibration" for more information about the calibration password.

4. Save any operating state (for example, press ).

5. Turn the power off and then back on.

A normal display free of error messages should appear. If not, the power supply requires service.

Runtime Error Messages

Under unusual operating conditions, the VOLT or AMPS display may show +OL or -OL. This indicates that the output
voltage or current is beyond the range of the meter readback circuit. Table 3-4 shows other error messages that may appear
at runtime.

Table 3-4. Runtime Errors

Display Meaning Display Meaning
EE WRITE ERR EEPROM status timeout UART FRAMING UART byte framing error
SBUB FULL Message too long for buffer UART OVERRUN Overfilled UART receive buffer
SERIAL DOWN Failed communication with UART PARITY UART byte parity error panel
front panel
STK OVERFLOW Front panel stack overflow

58 Turn-On Checkout
 4
User Connections

Rear Panel Connections (All Models)

Make application load connections to the output terminals or bus bars, analog connector, and digital connector as shown on
the rear-panel drawing for your model power supply. These connections are organized by series as follows:

l Series 664xA and 665xA

l Series 667xA
l Series 668xA and 669xA

Make controller connections (GPIB and serial link) as shown in Figure 4-6 at the end of this chapter.

Load Wire Selection (All Models)

Fire Hazard To satisfy safety requirements, load wires must be large enough not to overheat when
carrying the maximum short-circuit current of the power supply. If there is more than one load, then
any pair of load wires must be capable of safely carrying the full-rated current of the supply. With
the larger-capacity supplies (such as Series 668xA), use of two or more load wires in parallel may be
required.

Table 4-1 lists the characteristics of AWG (American Wire Gauge) copper wire.

Table 4-1. Stranded Copper Wire Capacity and Resistance

l 2 1 2
AWG Ampacity Resistance AWG Ampacity Resistance
No. (Ω/m) No. (Ω/m)
14 25 0.0103 2 140 0.00064
12 30 0.0065 1/0 195 0.00040
10 40 0.0041 2/0 225 0.00032
8 60 0.0025 3/0 260 0.00025
6 80 0.0016 4/0 300 0.00020
4 105 0.0010
NOTES:
1. Ampacity is based on 30 °C ambient temperature with conductor rated at 60 °C. For ambient temperature other
than 30 °C, multiply the above ampacities by the following constants:
Temp (°C) Constant Temp (°C) Constant
21-25 1.08 41-45 0.71
26-30 1.00 46-50 0.58
31-35 0.91 51-55 0.41
36-40 0.82
2. Resistance is nominal at 75 °C wire temperature.

User Connections 59
Analog Connector (All Models)
This connector, which is on the rear panel, is for connecting remote sense leads, external current monitors, and external
programming sources. The connector accepts wires sizes from AWG 22 to AWG 12.

• Insert Wires ‚ Tighten Screws

Agilent Series 664xA & 665xA Agilent Series 667xA, 668xA, & 669xA
IP Current programming input. IM Current monitor output.
VP Voltage programming input. VP Voltage programming input.
+IM Current monitor output. +IP Differential current programming input.
--IM Current monitor output. --IP Differential current programming input.
↓P Common for VP, IP and IM signals 1. ↓P Common for VP and IM signals 1.
+ S + remote sense input. +S + remote sense input.
--S -remote sense input. --S -remote sense input.
NOTE 1: Referenced to + output terminal.
Figure 4-1. Rear Panel Analog Connector

Note It is good engineering practice to twist and shield all signal wires to and from the analog and digital
connectors.

Digital Connector (All Models)

This connector, which is on the rear panel, is for connecting fault/inhibit, digital I/O, or relay link signals. The connector
accepts wires sizes from AWG 22 to AWG 12. Refer to Appendix D for more information about using this connector.

• Insert Wires ‚ Tighten Screws

1
FUNCTION
2
Pin No. Fault/Inhibit Digital I/O Relay Link
1 FLT OUTPUT OUT 0 RLY SEND
2 FLT OUTPUT OUT 1 NOT USED
3 INH INPUT IN/OUT 2 RLY RTN
4 INH COMMON COMMON COMMON

NOTES: Factory default function is FAULT/INHIBIT.

Output relay is not used with Series 668xA and 669xA.
Figure 4-2. Rear Panel Digital Connector

60 User Connections
Connecting Series 664xA and 665xA Power Supplies to the Load

• Output Safety Cover ‚ + Output Terminal ƒ - Output Terminal

„Signal Common … Output Sense Switch † Analog Connector
Figure 4-3a. Series 664xA and 665xA Rear Panel Output Connections

Output Isolation
The output of the power supply is isolated from earth ground. Either output terminal may be grounded, or an external
voltage source may be connected between either output and ground. However, both output terminals must be kept within
± 240 Vdc of ground. An earth ground terminal is provided on the rear panel for convenience, such as grounding wire
shields.

The earth ground terminal on the rear panel is a low-noise signal ground for convenience only. It is
not designed to function as a safety ground.

Load Considerations
Capacitive Loads

Effect on the Output Circuit. In most cases, the power supply will continue to be stable with additional external load
capacitors (see the following table for recommendations). However, large load capacitors may cause ringing in the supply's
transient response. It is possible that certain combinations of load capacitance, equivalent series resistance, and load lead
inductance will result in instability. If you need help in solving a stability problem, contact an Agilent service engineer
through your local Sales and Support Office (see end of this guide).

Series 664xA/665xA Power Supplies, Maximum External Capacitance (µF)

6641A 6642A 6643A 6644A 6645A 6651A 6652A 6653A 6654A 6655A
40,000 20,000 12,000 7,000 3,000 100,000 50,000 30,000 18,000 8,000

If the power supply output is rapidly programmed into capacitive loads, the supply may momentarily cross into CC mode.
This extends the CV programming time and limits the maximum slew rate to the programmed current divided by the total
internal (see the following section “Inductive Loads”) and external capacitance. These momentary crossovers into CC mode
will not damage the supply.

Effect on the OVP Circuit. The OVP circuit is designed to discharge fully-charged capacitances up to a specified limit for
each model. These limits are as follows:

User Connections 61
 Series 664xA/665xA Power Supplies, Maximum OVP External Capacitance (µF)
6641A 6642A 6643A 6644A 6645A 6651A 6652A 6653A 6654A 6655A
700,000 35,000 15,000 7,000 3,000 1.6 (F) 100,000 50,000 18,000 8,000

If a load capacitance approaches the specified limit, it is recommended that you do not make it a normal practice of tripping
the OVP circuit and discharging the load capacitance through that circuit. This could cause long-term fatigue in some circuit
components.

Because of its high output voltage, the Agilent 6555A generates very high currents when discharging
the load capacitor under overvoltage conditions. Excessive currents can damage the supply. The peak
discharge current is limited by the sum of the external capacitor's ESR (equivalent series resistance)
and the series resistance of the external circuit. For the Agilent 6555A external capacitance limit of
8,000 µF, this total resistance must be not less than 56 milliohms. For smaller values of external
capacitance, this resistance may be derated linearly.

Inductive Loads

Inductive loads provide no loop stability problems in CV mode. However, in CC mode inductive loads will form a parallel
resonance network with the power supply's output capacitor. Generally, this will not affect the stability of the supply, but it
may cause ringing of the current in the load. Ringing will not occur if the Q (quality factor) of the parallel resonant network
is ≤ 0.5. Use the following formula to determine the Q of your output.

1 L
Q=
Rint + Rext C

where: C = model-dependent internal capacitance (see below); L = inductance of the load; Rext = equivalent series
resistance of the load; Rint = model-dependent internal resistance (see below):

6641A 6642A 6643A 6644A 6645A 6651A 6652A 6653A 6654A 6655A
C= 4,200 µF 550 µF 180 µF 68 µF 33 µF 10,000 µF 1100 µF 440 µF 120 µF 50 µF
Rint = 7 mΩ 30 mΩ 50 mΩ 125 mΩ 300 mΩ 4 mΩ 20 mΩ 30 mΩ 80 mΩ 250 mΩ

Battery Charging

The power supply's OVP circuit contains a crowbar SCR that effectively shorts the output of the supply whenever OVP
trips. If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or
the output is programmed below the battery voltage, the power supply will continuously sink a large current from the
battery. This could damage the supply. To avoid this, insert a reverse blocking diode in series with the ⊕ output of the
supply. Connect the diode cathode to the + battery terminal and the diode anode to the supply ⊕ output terminal. The
diode may require a heat sink.

Note that if the OVP trips, you must remove the external current source in order to reset the internal SCR as part of clearing
the OVP circuit (see Clearing the OV Condition in “Chapter 5 - Front Panel Operation”).

Local Voltage Sensing

Your power supply was shipped set up for local sensing. This means that the supply will sense and regulate its output at the
output terminals, not at the load. Since local sensing does not compensate for voltage drops across screw terminals, bus
bars, or load leads, local sensing should only be used in applications that require low output current or where load regulation
is not critical.

Local sensing is obtained by placing the SENSE switch (see Figure 4-3a) in the Local position. The power supply is
shipped with the switch in this position.

62 User Connections
Note If the sense terminals are left unconnected, the voltage at the bus bars will increase approximately
3 to 5% over the programmed value. Since it is measured at the sense terminals, the voltage readback
will not reflect this increased output.

Remote Voltage Sensing

The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply
are connected directly to the load rather than to the output terminals. This allows the supply to automatically compensate for
the voltage drop in the load leads as well as to accurately read back the voltage directly across the load.

Setting Up Remote Sense Operation

Remote sensing is obtained by placing the SENSE switch (see Figure 4-3a) in the Remote position. The power supply is
shipped with the switch in the Local position.

Connecting the Sense Leads

You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the
-S analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If
sense leads are left open during operation, the supply will regulate at the output terminals instead of at the load. Remember
to bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.

CV Regulation

The voltage load regulation specification in Table 1-la and Table 1-2a applies at the output terminals of the power supply.
When remote sensing, this specification must be compensated. Add 3 mV to the voltage load regulation specification for
each 1-volt change in the positive load lead due to a change in load current. Because the sense leads are part of the supply's
feedback path, keep the resistance of the sense leads at or below 0.5 Ω to maintain the above specified performance.

OVP Considerations

The OVP circuit senses the voltage near the output terminals, not at the sense terminals. The voltage sensed by the OVP
circuit can be significantly higher than the voltage being maintained at the load. When using remote sensing, you must
program the OVP high enough to compensate for the expected voltage drop between the output and the load.

Output Rating

The rated output voltage and current specification in Table l-la and Table 1-2a applies at the output terminals of the power
supply. With remote sensing, any voltage dropped in the load leads causes the supply to increase the voltage at the output
terminals so it can maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load,
this forces the supply voltage at the output terminals to exceed the supply's rated output.

This will not damage the supply, but may trip the OVP (overvoltage protection) circuit, which senses the voltage at the
output. When operated beyond its rated output, the supply's performance specifications are not guaranteed, although typical
performance may be good. If the excessive demand on the supply forces it to lose regulation, the Unr annunciator will
indicate that the output is unregulated.

Output Noise

Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load
voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to
the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power
supply. Do not use the shield as one of the sense conductors.

User Connections 63
Stability

Using remote sensing under unusual combinations of load-lead lengths and large load capacitances may cause your
application to form a low-pass filter that becomes part of the voltage feedback loop. The extra phase shift created by this
filter can degrade the supply's stability and result in poor transient response. In severe cases, this may cause output
oscillations. To minimize this possibility, keep the load leads as short as possible and tie wrap them together.

In most cases, following the above guidelines will prevent problems associated with load lead inductance. This leaves load
load-lead resistance and load capacitance as the major source of reduced stability. Further improvement to the stability of
the supply may be obtained by keeping the load capacitance as small as possible and by decreasing the load-lead resistance
by using larger diameter wires. However, if heavy gauge wire (≥ AWG 10) is used, conditions may arise where the
load-lead inductance and load capacitance can form an undamped filter. This can actually reduce the damping in the system
and create a destabilizing phase response.

Note If you need help in solving a stability problem with any Series 664xA or 665xA power supply contact an
Agilent Service Engineer through your local Agilent Sales and Support Offices.

Connecting One Supply to the Load

Figure 4-3b and Figure 4-3c show how to connect a single power supply to one load and to multiple loads.

• Load Connection ‚ Load ƒ Analog Connector

A Set switch for local or optional remote sensing
B Connect for remote sensing (optional)

Figure 4-3b. Series 664xA and 665xA Single Load Connection

64 User Connections
• Load Connection ‚ Loads ƒ Analog Connector
A Set switch for local or (optional) remote sensing B Connect for remote sensing (optional)
Figure 4-3c. Series 664xA and 665xA Multiple Load Connection (Remote Sensing Optional)

Connecting Supplies in Auto-Parallel

Auto-Parallel Wiring. Figure 4-3d illustrates how power supplies can be connected in auto-parallel for increased current
output. You can connect up to three supplies of the same model .

Use load leads of a sufficient wire size so that the absolute voltage difference between the + output terminal of the "master"
supply and the + output terminal of the first "slave" supply is kept under 2 V at rated current. This also applies to the
voltage difference between the + output terminals of the first and second slave supplies. If remote sensing is required,
connect the load to the remote sense terminals of the master supply, as shown by the dashed lines in Figure 4-3d.

•Analog Connector ‚Slave Supply ƒ Master Supply

„Program only the master. Set slave output and OVP voltages slightly higher …Load
than the master to ensure that slaves stay in CC mode. †Connection
A Only local sensing permitted B Set switch for optional remote sensing C Connect for optional remote sensing
Figure 4-3d. Series 664xA and 665xA Auto-Parallel Connection (Remote Sensing Optional)

Note To avoid output oscillations, observe the wiring suggestions given under “External Voltage Control”.

User Connections 65
Auto-Parallel Programming. Program only the output current of the first ("master") supply in the series; the "slave"
supplies automatically track the master's output. Program the output current of the slave supplies to zero. However, the
voltage and OVP settings of the slave supplies must be set higher than the operating voltage of the master supply. This
ensures that the slave supplies will operate in CC mode. Functions such as status, voltage readback, and current readback
can still be read back individually for each supply.

If a "slave" supply experiences a desired shutdown condition (such as overtemperature or overcurrent), it will not
automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)
operation. See "Fault/Inhibit Operation" in Appendix D for wiring information and "Questionable Status Group" in
Chapter 4 of the Programming Guide for programming information.

Follow the following operating precautions if you are connecting three of these models in auto-parallel.

You must use caution when connecting three Series 664xA or 665xA power supplies for auto-parallel operation. That is
because of the OVP crowbar circuits within these supplies. If the OVP circuit of the second "slave" trips, its crowbar circuit
will draw current from the other two supplies. Although some models can withstand this current, the higher-current models
in each series (particularly the Agilent 6651A) may be damaged in this situation. Use any of the following operating
techniques to avoid possible problems.

1. Program Slave 2 OVP to the Maximum Level

The following technique minimizes the chance that the slave 2 OVP circuit will trip.
a. Program the OVP level of the master and of slave 1 to the desired protection level (below the maximum level specified in
Table 1-2).
b. Program the OV protection level of slave 2 to its maximum value.

2. Enable OCP on the Master

You can do this if the combination of all three supplies is being used in the CV mode and the CC mode is only being used as
a current limit. Enable OCP on the master supply. If the OVP on either slave trips it will drive the master into CC mode,
thereby tripping its OCP. This will shut down all three supplies. This technique will work unless the system is programmed
for very low (0.5 to 1.5) output voltages.

3. Insert Protection Diodes

If you connect the slave 2 supply to the load through a series diode (see Figure 4-3e), its OVP circuit will not draw current
from other supplies. Be certain to increase the programmed CV level of slave 2 by at least 0.7 V to compensate for the
voltage drop in the diode.

Figure 4-3e. Using Series Diodes with Series 664xA & 665xA Auto-Parallel Operation

Note Removing or disabling the power supply OVP crowbar SCR is another possibility. For further
information, contact a Agilent Service Engineer through your local Agilent Sales and Support Offices.

66 User Connections
Connecting Supplies in Series

Floating voltages must not exceed ±240 Vdc. No output terminal may be more than 240 V from
chassis ground.

Figure 4-3f shows how power supplies can be connected in series for higher voltage output.

Series connections are straightforward in this case. Program each power supply independently. If two supplies are used in
the series configuration, program each supply for 50% of the total output voltage. Set the current limit of each supply to the
maximum that the load can handle without damage.

Each power supply has a reverse voltage protection diode across its output. If a reverse voltage is
applied, the supply cannot control the current conducted through this diode. To avoid damaging the
supply, never connect it in such a way that a reverse voltage can force it to conduct current in
excess of the supply's maximum reverse diode current (see Table 1-2).

•Analog Connector ‚Load Connection ƒLoad

A Program each supply for full load current and 1/2 the load voltage B Set switch for local or (optional) remote sensing
C Connect for remote sensing (optional)
WARNING
FLOATING VOLTAGES MUST NOT EXCEED ±240 VDC. NO OUTPUT TERMINAL MAY
BE MORE THAN 240 V FROM CHASSIS GROUND

Figure 4-3f. Series 664xA and 665xA Series Connection (Remote Sensing Optional)

External Voltage Control

The setup shown in Figure 4-3g allows an external dc voltage to program the power supply output. A voltage applied to the
voltage programming input programs the output voltage and a voltage applied to the current programming input programs
the output current. See Figure 4-1 for an explanation of these programming input connections.

Wiring Considerations

The input impedance of the analog input is 10 kΩ. If the output impedance of your programming source is not negligible
with this, programming errors will result. Larger output impedances result in proportionally greater errors.

Be careful of capacitive coupling from the programming inputs to other lines wired to the analog connector. Such coupling
can cause output oscillations. You can minimize coupling by bundling the IP, VP, and Common P lines and keeping them
separated from other wires. Twisting these three lines together is also recommended.

User Connections 67
• Analog connector
l=Voltage programming source 0 to --5 V 2=Current programming source 0 to --5 V

Figure 4-3g. Series 664xA and 665xA Analog Programming Connections

If you cannot avoid capacitive coupling, it may help to place capacitors from the unused programming inputs to ground.
Especially with auto-parallel operation, connecting a capacitor (≥4,000 pF) from VP to P Common on the master supply
will ensure proper operation. Also with auto-parallel operation, do not allow more than about 500 pF capacitive loading
between IM and Common P.

Programming

Make certain that the common connection for your voltage programming source is isolated from the
load. Failure to do this may cause damage to the power supply.

The effect of the analog programming source is always summed with the values programmed over the GPIB or from the
front panel. The voltage source can act alone only if you set the other program sources to zero. Keep the total programmed
setting of the supply (the analog input summed with the GPIB or front panel settings) at or under the output ratings specified
in Table 1-1a. Exceeding the output ratings will not damage the supply, but it may not be able to regulate its output at the
higher levels. If this happens, the Unr annunciator will light to warn you that the output is unregulated.

When voltage programming the output, the frequency of the programming source is limited by the slew rate of the power
supply. To keep the power supply from slewing its output (going into nonlinear operation), the maximum programming rate
is 3750 V/s. The maximum downprogramming rate (when the power supply is sinking current) is 750 V/s. These restrictions
can be expressed as the maximum programming frequency that can be applied without causing distortion at the output. The
following formula can be used to determine this frequency:

FMAX = 50(voltage rating of supply)

p-p amplitude of desired output sine wave

At frequencies >6 kHz, voltage programming is subject to a 3 dB bandwidth limitation.

Connecting Series 667xA Power Supplies to the Load

Output Isolation
The output of the power supply is isolated from earth ground. Either output terminal may be grounded, or an external
voltage source may be connected between either output and ground. However, both output terminals must be kept within
± 240 Vdc of ground. An earth ground terminal is provided on the rear panel for convenience, such as grounding wire
shields.

68 User Connections
• Output Safety Cover ‚ Analog Connector ƒ-Output Bus Bar
„-Local Sense Terminal … + Local Sense Terminal †+ Output Bus Bar
‡ Signal Common ˆ Local Sense Jumpers ‰ Rear Knockouts
Š Bottom Knockout
A Insert screwdriver blade in slot and pry out B Bend along joint and break off
WARNING
DO NOT LEAVE UNCOVERED HOLES IN OUTPUT COVER. IF TOO MANY
KNOCKOUTS HAVE BEEN REMOVED, INSTALL A NEW COVER.

Figure 4-4a. Series 667xA Rear Panel Output Connections

The earth ground terminal on the rear panel is a low-noise signal ground for convenience only. It is not
designed to function as a safety ground.

Load Considerations
Capacitive Loads

In most cases, the power supply will continue to be stable with additional external load capacitors. However, large load
capacitors may cause ringing in the supply's transient response. It is possible that certain combinations of load capacitance,
equivalent series resistance, and load lead inductance will result in instability. If you need help in solving a stability
problem, contact a service engineer through your local Sales and Support Offices (see end of this guide).

If the power supply output is rapidly programmed into capacitive loads, the supply may momentarily cross into constant
current (CC) mode. This extends the CV programming time and limits the maximum slew rate to the programmed current
divided by the total internal and external capacitance. These momentary crossovers into CC mode will not damage the
supply.

Inductive Loads

Inductive loads provide no loop stability problems in CV mode. However, in CC mode inductive loads will form a parallel
resonance network with the power supply's output capacitor. Generally, this will not affect the stability of the supply, but it
may cause ringing of the current in the load. Ringing will not occur if the Q (quality factor) of the parallel resonant network
is ≤1.0. Use the following formula to determine the Q of your output.

User Connections 69
 1 L
Q=
R int + Re xt C

where: C = model-dependent internal capacitance (see below); L = inductance of the load; Rext = equivalent series
resistance of the load; Rint = model-dependent internal resistance (see below):

6671A 6672A 6673A 6674A 6675A

C= 44,000 µF 44,000 µF 12,000µF 7,000 µF 2,100 µF
Rint= 1.8 mΩ 2.2 mΩ 4 mΩ 14 mΩ 30 mΩ

If the Q is greater than 0.5, inductive loads will ring with the output capacitance and will be damped according to the
following equation:

δ=

Battery Charging

The power supply's OVP circuit has a downprogrammer FET that discharges the power supply output whenever OVP trips.
If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or the
output is programmed below the battery voltage, the power supply will sink current from the battery. To avoid this, insert a
reverse blocking diode in series with the ⊕ output of the supply. Connect the diode cathode to the + battery terminal and the
diode anode to the supply ⊕ output terminal. The diode may require a heat sink.

Local Voltage Sensing

Your power supply was shipped set up for local sensing. This means that the supply will sense and regulate its output at the
output terminals, not at the load. Since local sensing does not compensate for voltage drops across screw terminals, bus
bars, or load leads, local sensing should only be used in applications that require low output current or where load regulation
is not critical.

Local sensing is obtained by connecting the +LS sense terminal to the +S analog connector pin and the pin and the -LS
sense terminal to the -S analog connector pin. The power supply is shipped with these connections made.

Note If the sense terminals are left unconnected, the voltage at the bus bars will increase approximately
3 to 5% over the programmed value. Since it is measured at the sense terminals, the voltage readback
will not reflect this increased output.

Remote Voltage Sensing

The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply
are connected directly to the load rather than to the output terminals. This allows the supply to automatically compensate for
the voltage drop in the load leads as well as to accurately read back the voltage directly across the load.

Setting Up Remote Sense Operation

Remote sensing is obtained by removing the jumpers connecting the +LS sense terminal to the +S analog connector pin and
the -LS sense terminal to the -S analog connector pin. The power supply is shipped with these jumpers connected.

70 User Connections
Connecting the Sense Leads

You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the -S
analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense
leads are left open during operation, the supply will regulate at the output terminals instead of at the load. Remember to
bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.

CV Regulation

The voltage load regulation specification in Table 1-3a applies at the output terminals of the power supply. When remote
sensing, this specification must be compensated. Add an increment to the voltage load regulation specification as specified
by “∆mV” in the equation given under Load regulation in Table 1-3b.

OVP Considerations

The OVP circuit senses the voltage near the output terminals and not at the sense terminals. Depending on the voltage drop
between the output terminals and the load, the voltage sensed by the OVP circuit can be significantly higher than actually
being regulated at the load. You must program the OVP trip high enough to compensate for the expected higher voltage at
the output terminals.

Output Rating

The rated output voltage and current specification in Table 1-3a applies at the output terminals of the power supply. With
remote sensing, any voltage dropped in the load leads causes the supply to increase the voltage at the output terminals so it
can maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load, this forces the
supply voltage at the output terminals to exceed the supply's rated output. This will not damage the supply, but may trip the
OVP (overvoltage protection) circuit, which senses the voltage at the output bus bars. When operated beyond its rated
output, the supply's performance specifications are not guaranteed, although typical performance may be good. If the
excessive demand on the supply forces it to lose regulation, the Unr annunciator will indicate that the output is unregulated.

Output Noise

Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load
voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to
the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power
supply. Do not use the shield as one of the sense conductors.

Note The signal ground binding post on the rear panel is a convenient place to ground the sense shield.

Stability

Using remote sensing under unusual combinations of load-lead lengths and large load capacitances may cause your
application to form a low-pass filter that becomes part of the voltage feedback loop. The extra phase shift created by this
filter can degrade the supply's stability and result in poor transient response. In severe cases, this may cause output
oscillations. To minimize this possibility, keep the load leads as short as possible and tie wrap them together.

In most cases, following the above guidelines will prevent problems associated with load lead inductance. However, if a
large bypass capacitor is required at the load and load-lead length cannot be reduced, then a sense-lead bypass network may
be needed to ensure stability (see Figure 4-4b). The voltage rating of the 33 µF capacitors should be about 50% greater than
the anticipated load-lead drop. Addition of the 20-Ω resistors will cause a slight voltage rise at the remote sensing points.
For utmost voltage programming accuracy, the supply should be recalibrated with the DVM at the remote sensing points
(see “Appendix A - Calibration”).

Note If you need help in solving a stability problem with any Series 667xA power supply contact an Agilent
Service Engineer through your local Agilent Sales and Support Offices.

User Connections 71
• Load Leads ‚Remote Sense Points
Cl, C2 = 33 µF C3 = Load bypass capacitor R1, R2 = 20 Ω, 1%

Figure 4-4b. Series 667xA Sense Lead Bypass Network

Connecting One Power Supply to a Single Load

Figure 4-4c shows how to connect a single power supply to one load. Keep output load leads close together (small loop
area) to obtain a low inductance and low impedance connection to the load. If you wish to use remote sensing, connect the
sense leads at the load as shown in the figures.

•Load Connection ‚Load ƒAnalog Connector

A Connect for remote sensing (optional) B Connect for local sensing (default)

Figure 4-4c. Series 667xA Single Load Connection (Remote Sensing Optional)

Connecting One Power Supply To Multiple Loads

Figure 4-4d shows how to connect a single power supply to more than one load. When connecting multiple loads to the
power supply with local sensing, connect each load to the output bus bars with separate connecting wires. This minimizes
mutual coupling effects and takes full advantage of the supply's low output impedance. Keep each pair of load wires as short
as possible and twist or bundle them to reduce lead inductance and noise pickup.

72 User Connections
•Loads ‚Load Connection ƒAnalog Connector
A Connect for remote sensing (optional) B Connect for local sensing (default)

Figure 4-4d. Series 667xA Multiple Load Connection (Remote Sensing Optional)

Connecting Supplies in Auto-Parallel

Auto-Parallel Wiring (Figure 4-4e). Figure 4-4e illustrates how power supplies can be connected in auto-parallel for
increased current output. You can connect up to five supplies of the same model.

Use load leads of a sufficient wire size so that the absolute voltage difference between the + output terminal of the "master"
supply and the + output terminal of the first "slave" supply is kept under 2 V at rated current. This also applies to the
voltage difference between the + output terminals of the first and second slave supplies. If remote sensing is required,
connect the load to the remote sense terminals of the master supply, as shown by the dashed lines in Figure 4-4e.

• Analog Connector ‚ Slave Supply ƒ Master Supply

„Program only the master. Set slave output and OVP voltage slightly higher than the master to ensure that slave stays in
CC mode
… Load † Load Connection
A Only local sensing permitted B Connect for optional remote sensing

Figure 4-4e. Series 667xA Auto-Parallel Connection (Remote Sensing Optional)

User Connections 73
Auto-Parallel Programming. Program only the output current of the first ("master") supply in the series; the "slave"
supplies automatically track the master's output. Program the output current of the slave supplies to zero. However, the
voltage and OVP settings of the slave supplies must be set higher than the operating voltage of the master supply. This
ensures that the slave supplies will operate in CC mode. Functions such as status, voltage readback, and current readback
can still be read back individually for each supply.

If a "slave" supply experiences a desired shutdown condition (such as overtemperature or overcurrent), it will not
automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)
operation. See "Fault/Inhibit Operation" in "Appendix D - Digital Port Functions" for wiring information and "Questionable
Status Group" in Chapter 4 of the "Programming Guide" for programming information.

Connecting Supplies in Series

Floating voltages must not exceed 240 Vdc. No output terminal may be more than 240 V from chassis
ground.

Figure 4-4f shows how power supplies can be connected in series for higher voltage output. Series connections are
straightforward in this case.

Program each power supply independently. If two supplies are used in the series configuration, program each supply for
50% of the total output voltage. Set the current limit of each supply to the maximum that the load can handle without
damage.

Each power supply has a reverse voltage protection diode across its output. If a reverse voltage is
applied, the supply cannot control the current conducted through this diode. To avoid damaging the
supply, never connect it in such a way that a reverse voltage can force it to conduct current in excess
of the supply's maximum reverse diode current (see Table 1-2b).

•Load Connection ‚ Analog Connector ƒ Load

„ Program each supply for full load current and 1/2 the load voltage

A Connect for remote sensing (optional)

WARNING
FLOATING VOLTAGES MUST NOT EXCEED ±240 VDC NO OUTPUT TERMINAL MAY
BE MORE THAN 240 V FROM CHASSIS GROUND.

Figure 4-4f. Series 667xA Series Connection (Remote Sensing Optional)

74 User Connections
External Voltage Control
The setup shown in Figure 4-4g allows an external dc voltage to program the power supply output. A voltage applied to the
voltage programming input programs the output voltage and a voltage applied to the current programming input programs
the output current. See Figure 4-1 for an explanation of these programming input connections.

Wiring Considerations (Figure 4-4g)

The input impedance of the analog input is over 30 kΩ. If the output impedance of your programming source is not
negligible with this, programming errors will result. Larger output impedances result in proportionally greater errors.

1 Voltage programming source 0 to -5V

2 Differential current programming source 0 to +10 V
3 Differential current programming source 0 to -10 V
4 Current programming source (floating) 0 to 10 V

* Maximum Potential between -IP and ↓P is ±15 V

Figure 4-4g. Series 667xA Analog Programming Connections

Programming

Note from Figure 4-1 that you have three options for programming the current. You can use a voltage source that is positive,
negative, or floating with respect to Common P. Do not exceed ±19 V with respect to Common P.

Make certain that the common connection for your voltage programming source is isolated from the
load. Failure to do this may cause damage to the power supply.

The effect of the analog programming source is always summed with the values programmed over the GPIB or from the
front panel. The voltage source can act alone only if you set the other program sources to zero. Keep the total programmed
setting of the supply (the analog input summed with the GPIB or front panel settings) at or under the output ratings specified
in Table 1-2a. Exceeding the output ratings will not damage the supply, but it may not be able to regulate its output at the
higher levels. If this happens, the Unr annunciator will light to warn you that the output is unregulated.

User Connections 75
Connecting Series 668xA and 669xA Power Supplies to the Load

ENERGY HAZARD. These power supplies can provide more than 240 VA at more than 2 V. If the
output connections touch, severe arcing may occur resulting in burns, ignition or welding of parts. Do
not attempt to make connections to live output circuits.

• Analog Connector ‚ -Output Bus Bar ƒ -Local Sense Tap

„ + Output Bus Bar … + Local Sense Tap † Signal Common
A Option 601 cover required for bench installation

Figure 4-5a. Series 668xA and 669xA Rear Panel Output Connections

Output Isolation

Except for a high value (>1 MΩ) internal bleeder resistor, the output of the power supply is isolated from earth ground.
Either output terminal may be grounded or an external dc voltage source may be connected between either output and
ground. However, both output terminals must be kept within ±60 Vdc of ground.

The earth ground terminal located near the output bus bars is a low-noise signal ground for
convenience only. It is not designed to function as a safety ground.

Load Considerations
Capacitive Loads

In most cases, the power supply will maintain stability with external load capacitors. However, large load capacitors may
cause ringing in the supply's transient response. It's possible that certain combinations of load capacitance, equivalent series
resistance, and load-lead inductance will result in instability (see also “Stability” under “Remote Sensing”). If you need help
solving a stability problem, contact an Agilent Service Engineer through your local Agilent Sales and Support Offices.

If the output is rapidly programmed into capacitive loads, the power supply may momentarily cross into CC operation,
thereby extending the CV programming time. When it crosses into CC mode, the supply's maximum slew rate is limited by
the CC loop and is a function of the loop current compensation. This may be optimized for particular compensation. These
momentary crossover situations, which are communicated via the status register, may increase programming times, but will
not damage the power supply.

76 User Connections
Inductive Loads

Inductive loads present no loop stability problems in CV mode. In CC mode, inductive loads will form a parallel resonance
with the power supply's output capacitor, possibly causing current ringing in the load. For a given inductance, the power
supply's CC control loop can be made to stabilize the current. However, stabilizing the current for a very large load
inductance creates a much slower mode crossover (CV to CC or vice versa) time. Thus, there is a tradeoff between mode
crossover speed and inductive compensation. To allow an optimal solution for each load, a CC loop compensation switch is
provided so the CC control loop can be optimized for a specific load inductance. See "Appendix E - Current Loop
Compensation" for details.

Battery Charging

The power supply's OVP circuit has a downprogrammer FET that discharges the power supply output whenever OVP trips.
If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or the
output is programmed below the battery voltage, the power supply will sink current from the battery. To avoid this, insert a
reverse blocking diode in series with the ⊕ output of the supply. Connect the diode cathode to the + battery terminal and
the diode anode to the supply ⊕ output terminal. The diode will require a heat sink.

Local Voltage Sensing

For local sensing the +S and--S analog connector pins must be connected to the + and - bus bars (see Figure 4-5b). This is
the default configuration as wired at the factory. Each sense lead is connected to the small, tapped hole nearest the
corresponding output lead. Since local sensing does not compensate for voltage drops in the screw connections or load
leads, local sensing should only be used in applications that require low output currents or where load regulation is not
critical.

Note If the sense terminals are left open, the voltage at the output bus bars will increase approximately 3 to 5%
over the programmed value. The readback voltage will not reflect this increase because readback is
measured at the sense terminals.

Remote Voltage Sensing

The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply
are connected directly to the load rather than to the output bus bars. This allows the supply to automatically increase the
voltage at the output bus bars to compensate for any voltage drop in the load leads, as well as to accurately read back the
voltage directly from the load.

Setting Up Remote Sense Operation

You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the -S
analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense
leads are left open during operation, the supply will regulate at the output bus bars instead of at the load. Remember to
bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.

The sense leads are part of the supply's feedback path and must be kept at a low resistance in order to maintain optimal
performance. Connect the sense leads carefully so that they do not become open-circuited. If the sense leads are left
unconnected or become open during operation, the supply will regulate at the output bus bars, resulting in a 3 to 5% increase in
output over the programmed value.

CV Regulation

The maximum output voltage under remote sensing is reduced by the voltage drop in the load leads. See “Remote Sensing
Capability” in Table 1-3b for further characteristics and a general formula for determining the extra degradation in the output
due to voltage drop in the output leads.

User Connections 77
OVP Considerations

The power supply OVP circuit senses voltage near the output bus bars, not at the load. Therefore the signal sensed by the
OVP circuit can be significantly higher than the actual voltage at the load. When using remote sensing, you must program the
OVP trip voltage high enough to compensate for the voltage drop between the output bus bars and the load.

Output Rating

In remote sense applications, the voltage drop in the load leads subtracts from the available load voltage. As the power
supply increases its output to overcome this voltage drop, the sum of the programmed voltage and the load-lead drop may
exceed the power supply's maximum voltage rating. This will not damage the supply, but may trip the OV protection circuit,
which senses the voltage at the output bus bars. When the supply is operated beyond its rated output the performance
specifications are not guaranteed, although typical performance may be good.

Output Noise

Any noise picked up on the sense leads may appear at the output of the supply and can adversely affect the voltage load
regulation. Use shielded twisted pairs for the sense leads and route them parallel and close to the load leads. Ground the
shields only at the power-supply end, utilizing the signal ground binding post. Do not use a shield as one of the sense
conductors. Bundle or tie-wrap the load leads to minimize inductance and reduce noise pickup.

Stability

Using sensing under unusual combinations of load lead lengths and large load capacitances may cause your application to
form a low-pass filter, which becomes part of the voltage feedback loop. The extra phase shift created by this filter can degrade
the supply's stability, resulting in poor transient response. In severe cases, it may cause oscillation. To minimize this possibility,
keep the load leads as short as possible and tie wrap them together.

In most cases, following these guidelines will eliminate problems associated with load lead inductance. However, if a large
bypass capacitor is required at the load and load-lead length cannot be reduced, then a sense-lead bypass network may be
needed to ensure stability (see Figure 4-5b).

The voltage rating of the 33 µF capacitors should be about 50% greater than the anticipated load-lead drop. Addition of
the 20 Ω resistors will cause a slight voltage rise at the remote sensing points. For utmost voltage programming accuracy,
the supply should be recalibrated with the DVM at the remote sensing points (see “Appendix A - Calibration”). In
addition, the sense protect resistors inside the power supply may have to be removed. (If you need help with a stability
problem, contact an Support Engineer through your local Agilent Sales and Support offices.)

• Load Leads ‚ Remote Sense Points

C1, C2 = 33µF C3 = Load bypass capacitor Rl, R2 = 20 Ω, 1%
Figure 4-5b. Series 668xA and 669xA Sense Lead Bypass Network

78 User Connections
Connecting One Power Supply to a Single Load
Figure 4-5c shows how to connect a single power supply to one load. Keep output load leads close together (small loop
area) to obtain a low inductance and low impedance connection to the load. If you wish to use remote sensing, connect the
sense leads at the load as shown in the figures.

• Analog Connector ‚ Load Connection ƒ Load „ Nut

… Lockwasher † Flatwasher ‡ 3-8 inch bolt
A Connect for remote sensing (optional) B Connect for local sensing (default)
Figure 4-5c. Series 668xA and 669xA Single Load Connection (Remote Sensing Optional)

Note If you are using a bench application requiring the Option 601 Output Connector Kit, be sure to consult
the instructions supplied with the kit.

Connecting One Power Supply to Multiple Loads

Figure 4-5d shows how to connect a single power supply to more than one load. When connecting multiple loads to the
power supply with local sensing, connect each load to the output bus bars with separate connecting wires. This minimizes
mutual coupling effects and takes full advantage of the supply's low output impedance. Keep each pair of load wires as
short as possible and twist or bundle them to reduce lead inductance and noise pickup.

•Load ‚Load Connection ƒAnalog Connector

A Connect for remote sensing (optional) B Connect for local sensing (default)

Figure 4-5d. Series 668xA and 669xA Multiple Load Connection (Remote Sensing Optional)

User Connections 79
Connecting Supplies in Auto-Parallel

Note Refer to Appendix F for more information about auto-parallel operation.

Auto-Parallel Wiring (Figure 4-5e). Figure 4-5e shows how power supplies can be auto-paralleled for increased current
output. Up to three supplies can be connected for auto-parallel operation. Use heavy enough load leads so that the absolute
voltage difference between the ⊕ output terminals of the "master" supply and the ⊕ output terminal of the first "slave"
supply is kept under 2 V at rated current. This also applies to the voltage difference between the ⊕ output terminals of the
first and second "slave" supplies. If remote sensing is necessary, connect the remote sense terminals of the "master" supply
as shown by the dashed lines in Figure 4-5e. See "Remote Voltage Sensing" for more information.

Auto-Parallel Programming. Program only the output current of the first ("master") supply in the series; the "slave"
supplies automatically track the master's output. Program the output current of the slave supplies to zero. However, the
voltage and OVP settings of the slave supplies must be set higher than the operating voltage of the master supply. This
ensures that the slave supplies will operate in CC mode when tracking the output of the master supply. Be sure to set the
output current of the slave supplies to zero, because all current programming inputs (GPIB, front panel, and external
voltage) are additive. Functions such as status, voltage readback, and current readback can still be read back individually
for each supply.

If a "slave" supply experiences a desired shutdown condition (such as caused by overtemperature or overcurrent), it does
not automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)
operation. It is recommended that you use the RI and DFI functions to automatically shut down all supplies whenever one
supply experiences a shutdown condition. See "Fault/Inhibit Operation" in "Appendix D - Digital Port Functions" for
wiring information and "Questionable Status Group" in the "Programming Guide" for programming information.

• Analog Connector ‚ Slave Supply ƒ Master Supply

„Program only the master. Set slave output and OVP voltage slightly higher than the master to ensure that slave stays in
CC mode
… Load † Load Connection
A Only local sensing permitted B Connect for remote sensing (optional)
Figure 4-5e. Series 668xA and 669xA Auto-Parallel Connection (Remote Sensing Optional)

80 User Connections
Connecting Supplies in Series

Floating voltages must not exceed ± 60 Vdc. No output terminal may be more than 60 V from chassis
ground.

Figure 4-5f illustrates how power supplies can be connected in series for increased voltage capability. Series connections
are straightforward in this case.
Program each power supply as an independent supply. If two supplies are used in series operation, each supply can be
programmed to deliver 50% of the total output voltage. Set the current limit of each power supply to the maximum that the
load can handle without damage.

If one supply experiences a desired shutdown condition (such as caused by overtemperature or overcurrent), it does not
automatically shut down the other supply. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)
operation. It is recommended that you use the RI and DFI functions to automatically shut down both supplies whenever one
supply experiences a shutdown condition. See "Fault/Inhibit operation" in "Appendix D - Digital Port Functions" for wiring
information and "Questionable Status Group" in the "Programming Guide" for programming information.

• Analog Connector ‚ Load ƒ Load Connection

„ Program each supply for full load current and 1/2 the load voltage
A Connect for remote sensing (optional) B Connect for local sensing (default)
WARNING
FLOATING VOLTAGES MUST NOT EXCEED ±60 VDC. NO OUTPUT TERMINAL MAY
BE MORE THAN 60 V FROM CHASSIS GROUND.
Figure 4-5f. Series 668xA and 669xA Series Connection (Remote Sensing Optional)

Each power supply has a reverse voltage protection diode across its output. If the fan in one of the
series power supplies shuts down for any reason (such as a fan circuit defect or loss of ac power), the
supply may severely overheat due to current forced through its reverse current diode by the functioning
supply. This possibility can be eliminated by use of the Rl/DFI functions previously noted. Also, if a
reverse voltage is applied across a functioning supply, it has no control over the current conducted
through this diode. To avoid damaging the supply, never connect it in such a way that a reverse voltage
can force it to conduct current in excess of the supply's maximum rated current. (see Table 1-4b)

User Connections 81
External Voltage Control
The setup shown in Figure 4-5g allows an external dc voltage to program the power supply output. A zero-to-full scale
voltage applied to the voltage programming input produces a proportional zero-to-full scale output voltage. The voltage
programming source is referenced to the programming Common P (↓P) terminal. A zero-to-full scale voltage applied to
one of the current programming inputs produces a proportional zero-to-full scale output current. See Figure 4-1 for an
explanation of these programming input connections.

Wiring Considerations

The input impedance of the analog input is over 30 kΩ. If the output impedance of your programming source is not negligible
with this, programming errors will result. Larger output impedances result in proportionally greater errors.

1 = Voltage programming source 0 to -5 V

2 = Current programming source 0 to +5 V
3 = Current programming source 0 to -5 V
4 = Current programming source floating 0 to 5 V

* Maximum potential between -IP and ↓P or between +IP and ↓P is ±15 V

Figure 4-5g. Series 668xA and 669xA Analog Programming Connections

Programming

Note from Figure 4-1 that you have three options for programming the current. You can use a voltage source that is positive,
negative, or floating with respect to Common P. Do not exceed +15 V with respect to Common P.

Make certain that the common connection for your voltage programming source is isolated from the load.
Failure to do this may cause damage to the power supply.

The effect of the analog programming source is always summed with the values programmed over the GPIB or from the front
panel. The voltage source can act alone only if you set the other program sources to zero. Keep the total programmed setting of
the supply (the analog input summed with the GPIB or front panel settings) at or under the output ratings specified in Table 1-3a.
Exceeding the output ratings will not damage the supply, but it may not be able to regulate its output the higher levels. If this
happens, the Unr annunciator will light to warn you that the output is unregulated.

82 User Connections
Controller Connections
Figure 4-6 shows two basic ways of connecting your power supply to a controller. They are "linked" and "stand-alone
configurations.

Stand-Alone Connections
See Figure 4-6A. Each stand-alone power supply has its own GPIB bus address. Stand-alone power supplies may be
connected to the bus in series configuration, star configuration, or a combination of the two. You may connect from
1 to 15 stand-alone power supplies to a controller GPIB interface.

Linked Connections
See Figure 4-6B. Up to 16 power supplies may be used at a single GPIB primary bus address by making linked
connections. (You cannot use linked connections if you intend to program power supplies with the Compatibility
Language - see the power supply “Programming Guide".)
n The first power supply in a linked connection is a "direct supply" connected to the controller via a GPIB cable. The
direct supply is the only supply connected directly to the bus and has a unique primary bus address.
n The remaining power supplies are "linked supplies” connected to the direct supply via a serial-link cable. Each
linked supply has a unique secondary GPIB address and derives its primary address from the direct supply. You may
connect from 1 to 15 linked supplies to each direct supply.

Note The power supply is shipped from the factory with its GPIB address set to 5. The power supply primary
and secondary addresses can be changed from the front panel as described in "Chapter 2 - Remote
Programming" of the "Programming Guide". For power supply GPIB interface capabilities, see Table
1-5 in Chapter 1 of this guide.

User Connections 83
• From 1 to 16 direct supplies may be connected to 1 controller GPIB interface.
‚ Tighten connector thumbscrews by hand. Do not use a screwdriver.
ƒ Do not stack more than 3 connectors on a GPIB receptacle.
„ GPIB cable (see Accessories in Chapter 1)
… From 1 to 15 linked supplies may be connected to 1 direct supply.
† Either receptacle (Jl or J2) may be used as an input or an output.
‡
Serial Link Cable (see Accessories in Chapter 1), 2 meters. 1 is supplied.
A
Maximum total length of all GPIB cables (including controller) not to exceed 20 meters.
Use caution with individual lengths over 4 meters.
B
Maximum total length of all serial cables not to exceed 30 meters.

NOTES:
1. A direct power supply is connected to the controller interface and must have a unique primary GPIB bus address.
2. The stand-alone configuration uses only direct supplies connected to the controller interface.
3. The linked configuration uses 1 or more linked power supplies connected to each direct supply. Each linked supply has
a unique secondary GPIB bus address and derives its primary address from the direct supply.

Figure 4-6. Controller Connections

84 User Connections
 5
Front Panel Operation

Introduction
This chapter shows you how to operate the front panel. It is assumed that you are familiar with the turn-on checkout
procedure in Chapter 3. That chapter describes how to perform basic power supply functions from the control panel.
operations that you can perform are:

n Enabling or disabling the power supply output.

n Setting the output voltage and current.
n Monitoring the output voltage and current.
n Setting the overvoltage protection (OVP) trip point.
n Enabling the overcurrent protection (OCP) circuit.
n Saving operating states in nonvolatile memory.
n Recalling operating states from nonvolatile memory.
n Setting the power supply GPIB bus address.
n Displaying error codes created during remote operation.
n Enabling local (front panel) operation.

Note You also can calibrate the power supply from the front panel (see Appendix A).

Getting Acquainted
The front panel is summarized in Figure 5-1 and Table 5-1. Note that the panel is organized as follows:

• LCD display (including annunciators)

‚ Output VOLTAGE and CURRENT rotary (RPG) knobs
ƒ SYSTEM keypad
„ FUNCTION keypad
… ENTRY keypad
† Power (LINE) switch

Some keys have two functions. For example, the System key (3, Figure 5-1) can be used either to recall a stored
operating state or to (store) an operating state. The first operation is shown on the key and the second (shifted)
operation is shown in blue above the key. In order to do a shifted operation, first press the solid blue key, which is
unlabeled but shown throughout this manual as .

For example, for a recall operation, press the recall key . For a save operation, press the save key, which is
. When you do this, the Shift annunciator will light to remind you that the key is now functioning as
the key. In this chapter, such a shifted operation may be shown simply as .

Front Panel Operation 85

 1 2 3 4 5

6681A 0-8V/0-580A
SYSTEM DC POWER SUPPLY

S YSTE M FUNCTION ENTRY

VOLTS AMPS
Local Output Voltage
on/off 7 8 9
Voltage
Error Prot Clear VCal ICal OVCal
Addres s Protect Current Voltage
4 5 6
CV CC Unr Dis OCP Prot Err Cal Shift Rmt Addr SRQ
Save Cal Enable Cal Disable Pass
Recall OCP OV Enter
VOLTAGE CURRENT 1 2 3
Current
Cal Save - Clear Entry

Current
0 .

On

Off

Figure 5-1. Front Panel Controls and Indicators

Table 5-1. Front Panel Controls and Indicators (see Figure 5-1)
Control or Function or Indication
Indicator
• Display

VOLTS Shows present output voltage of the power supply.

AMPS Shows present output current of the power supply.
Status Annunciators
CV The power supply is in constant-voltage mode.
CC The power supply is in constant-current mode.
Unr The power supply output is unregulated (output is neither CV or CC).
Dis The power supply output is disabled.
OCP The overcurrent protection function is enabled.
Prot A protection circuit has caused the power supply to shut down. (Press to determine the reason.)
Err An error has been generated as a result of remote operation. (Press to display the error code).
Cal The power supply is in calibration mode.
Shift The shift key has been pressed.
Rmt The power supply is in the remote mode (controlled over the GPIB).
Addr The power supply is addressed to listen or talk.
SRQ The power supply is requesting service from the controller.

86 Front Panel Operation

 Table 5-1. Front Panel Controls and Indicators (continued)
‚Output Rotary Controls
Voltage Rotate clockwise to increase output voltage or program setting. Use to rapidly set an approximate output
value (see and keys).
Current Rotate clockwise to increase output current or program setting. Use to rapidly set an approximate current
value (see and keys).
ƒ SYSTEM Keys
When the power supply is under remote control, press to enable local operation. This control can be
defeated by a lock-out command over the GPIB
Press to display the power supply's GPIB address. You can change the address with the ENTRY keys
Use to display error codes generated during remote operation. (Select by pressing .)
Use to restore a previously saved power supply state. Use ENTRY keys through ( through on
the Series 668xA) to specify which location to recall. (Select by pressing .)
Note: Location 0 may contain the power supply turn-on state. See "Turn-on operation" in this chapter.

Use to save the power supply’s present state to nonvolatile memory. (Select by pressing .)
Use ENTRY keys to specify the location where you want to store the state. You may use locations
through ( through on the Series 668xA).

This unlabeled blue key is the Shift key. Press to access the shifted (alternate) key functions.

„ Function Keys

Press to enable or disable the power supply output. This key toggles between the two states. The disabled
state programs the output to the *RST voltage and current settings (see the Programming Guide).

Press to display the output voltage setting. After pressing , you may use the ENTRY keys to
change the value.

Press to display the output current setting. After pressing , you may use the ENTRY keys to
change the value.
Press to display the OV trip voltage setting. After pressing , you may use the ENTRY keys to change
the value.
When the Prot annunciator is on, press to see which protection circuit caused the power supply
to shut down. Response can be OC (overcurrent), OT (overtemperature), or OV (overvoltage). If no
protection circuit has tripped, the display will show dashes (- - - -).

Press this key to reset the protection circuit. If the condition that caused the circuit to trip has been
removed, the Prot annunciator will go off.

Press to enable or disable the power supply OCP trip circuit. This key toggles between the two states.
which are indicated by the OCP annunciator.

… ENTRY Keys
Press to increment the output voltage in the CV mode, or to increase the voltage setting after you have
pressed the key. 3

Press to decrement the output voltage in the CV mode, or to decrease the voltage setting after you have
pressed the key.3
Press to increment the output current in the CC mode, or to increase the current setting after you have
pressed the key.3
Press to decrement the output current in the CC mode, or to decrease the current setting after you have
pressed the key.3

Front Panel Operation 87

 Table 5-1. Front Panel Controls and Indicators (continued)
… ENTRY Keys (continued)
thru Press to select numerical values .

Press to enter a minus sign.

Press to delete the last keypad entry. Use this key to remove one or more incorrect digits before they are
entered.
3
These four entry keys operate in two modes. Press and release for a single minimal change as
determined by the programming resolution (see Table 1-2 in Chapter l). Press and hold for an increasingly
rapid output change.

Press to delete an entire keypad entry and return to the meter mode. Use this key to exit from a value
before it is entered.
Press to enter a value or to accept an existing value and return the display to the meter mode.
The remaining shifted keys are for calibration (see "Appendix A - Calibration").
† Line Switch
On / Off Turns the ac line on or off.

Programming the Output

Important These instructions show how to program a single power supply. There are special considerations when
you have two or more supplies connected in series or in autoparallel. See "Chapter 4 - User Connections
and Considerations".

The power supply accepts values directly in volts and amperes. Values will be rounded off to the nearest multiple of the
output resolution (see “Average Resolution" in Table 1-2 of Chapter 1). If you attempt to enter a value not in a valid range,
the entry will be ignored and OUT OF RANGE appears on the display.

Figure 5-2 shows the general response of a typical power supply. Unless directed otherwise, always keep the output voltage
and current within the boundaries of its operating line for the specified mode of operation (CV or CC).

Establishing Initial Conditions

Set the power supply to its *RST state by pressing . This state was stored in location 0 at the factory. If it
has since been changed, you can restore it as directed under “Turn-on Conditions”, later in this chapter. *RST results in the
following operating conditions:

n Zero voltage output.

n Minimal current output.
n Output disabled (Dis annunciator on).
n Overcurrent protection off (OCP annunciator off).
n Protection circuits cleared (Prot annunciator off).

88 Front Panel Operation

 Figure 5-2. Typical Power Supply Operating Curve

Programming Voltage
To program the output for 4.5 volts, proceed as follows:

n Press . The display will change from meter mode to indicate VOLTS.
n Press . If you discover a mistake before pressing , erase the incorrect value with the backspace
key .
n The display will return to the meter mode and indicate 0.000 volts.
n Press to enable the output (Dis annunciator turns off). The VOLTS display will indicate 4.500 volts.

Note The power supply must be programmed for a minimal current in order to increase the output voltage
beyond zero. Normally, there is sufficient idle current to do this. If the power supply does not respond or
the CC annunciator turns on, go to “Programming Current” and set the current to a small value.

n Now raise the voltage by pressing .Note that the voltage increases by a specific increment (depending on the
voltage programming resolution) each time you press the key and increases rapidly as you hold down the key. To lower
the voltage, press .
n Try raising and lowering the voltage by rotating the Voltage control clockwise and then counterclockwise. Note how the
output responds as compared to using the Entry keys.

Try to program a voltage greater than the VMAX for your supply (see "Supplemental Characteristics" for your particular
model in Chapter 1). Note that the display shows OUT OF RANGE.

Programming Overvoltage Protection

Overvoltage protection guards the load against voltages that reach a specified value above the programmed output voltage.

Setting the OVP Level

Assuming that you have programmed the power supply for 4.5 volts, you can set the OVP level to 4.8 volts as follows:
n Press . The display will change from meter mode to indicate 0V, followed by the present OVP value.
n Press .
n The display will return to the meter mode and indicate the output (4.500 volts).
n Press again. The display will now indicate 0V 4 . 800.
n Press to return to the meter mode.

Front Panel Operation 89

Checking OVP Operation

Assuming the above operating conditions (voltage programmed to 4.5 V and OVP programmed to 4.8 V), trip the OVP
circuit as follows:

n Gradually increase the output voltage by pressing until the OVP circuit trips. This will cause the output
voltage to drop to zero and the Prot annunciator to go on.
n There now is no power supply output due to an overvoltage condition.
n To verify this, press and observe that the display indicates 0V. This shows that the protection circuit tripped
due to an overvoltage condition.

Clearing The OVP Condition

With the OVP tripped, return to the meter mode and try to clear the condition by pressing . Nothing will appear
to happen because the OV trip voltage is still below the programmed output voltage. Thus, as soon as the circuit is cleared,
it trips again. You can clear the OV condition by:

n Lowering the output voltage below 4.8 (the OV setting), or

n By raising the OV trip voltage above the output voltage setting.

Try either of these methods. Now when you press , the Prot annunciator will turn off and the output voltage will
return to normal.

Programming Current

ENERGY HAZARD. Some power supplies (Series 668xA) can provide more than 240 VA at more
than 2 V. If the output connections touch, severe arcing may occur resulting in burns, ignition or
welding of parts.

You may program the power supply current without a load, but must have a load in order to draw output current. These tests
assume you have the load connected in accordance with the information in “Chapter 4 - User Connections and
Considerations”. If you do not have a load on the power supply, you may connect a short across the output terminals as
described in “Chapter 3 - Turn-on Checkout”.

The example will program a low current. (You may later increase the output current to the levels you will expect to use.) To
program the output current to 1.3 amperes, proceed as follows:

n Disable the output by pressing . The Dis annunciator will turn on.
n Program the voltage by pressing .
n Press . The display will change from meter mode to indicate AMPS.
n Press . If you discover a mistake before pressing erase the incorrect value with the backspace
key .
n The display will return to the meter mode and indicate up to 0 . 000.
n Press to enable the output. Dis will turn off and the display will indicate VOLTS 5 . 000 AMPS 1. 300.
n Now increase the current by pressing . Note that the current increases by a specific increment (depending on
the current programming resolution) each time you press the key and increases rapidly as you hold down the key. To
decrease the current, press .
n Try increasing and decreasing the current by rotating the Current knob clockwise and counterclockwise. Note how the
output responds as compared to using the Entry keys.

Disable the output by pressing . The Dis annunciator will turn on. Now try to program a current greater than
the IMAX for your supply. Note that the display shows OUT OF RANGE.

90 Front Panel Operation

Programming Overcurrent Protection
When enabled, overcurrent protection removes the power supply output whenever it goes into CC operation. This prevents
the supply from indefinitely supplying the full programmed current to the load.

Setting The OCP Protection

To activate overcurrent protection, press . The OCP annunciator will light and power supply will continue to operate
normally until it is forced into CC operation. If that occurs, the OCP circuit will trip and the power supply will remove its
output.

Checking OCP Operation

The easiest way to check this operation at any specified current is to increase the load current beyond the programmed
current value and, if necessary, decrease the programmed voltage. This will force the power supply into the CC mode (see
Figure 5-2). When OCP trips, the Prot annunciator will light and the power supply output will drop to zero.

There is now no power supply output due to an overcurrent condition. To verify this, press and observe that the
display indicates OC.

Clearing The OCP Condition

With the OCP tripped, return to the meter mode and try to clear the condition by pressing . Nothing will appear to
happen because the reason for the condition has not been removed. Thus, as soon as the circuit is cleared, it trips again. You
can clear the OC condition by:

n Increasing the load resistance to lower the output current below the programmed current value, or
n By raising the programmed current to a value above that required by the load.

Clear the fault by either of the above methods. Then clear the OCP circuit by pressing . The Prot annunciator will
go off and the power supply output will be restored to normal.

If desired, you can also restore the output by disabling the OCP function (press to turn off the OCP annunciator).
This restores the output but does not clear any condition that may have caused OCP to trip.

Note Under certain conditions, the OCP circuit may fail to clear because load demand occurs before the power
supply has time to build up the required output current capacity. In such cases, disable the output (press
before clearing the OCP circuit). After OCP is cleared, enable the power supply output.

CV Mode vs. CC Mode

Once you program a voltage (VS) and a current (IS) in Figure 5-2, the power supply will try to maintain itself in either CV or
CC mode, depending on the impedance of the load (RL). If the load demands less current than Is, operation will be in CV
mode with the voltage maintained at Vs. The output current will be at some value below Is as determined by VS ÷ RL.

If the current increases beyond IS (see RL2), the supply will switch to CC mode by varying its output voltage to maintain a
constant current value of Is. As more current is demanded, the voltage decreases to maintain the increased current level. If
the load current increases to the maximum output of the power supply, the output voltage will be maintained at a near-zero
level.

Front Panel Operation 91

Unregulated Operation
If the power supply goes into a mode of operation that is neither CV nor CC, the Unr annunciator will light. An unregulated
condition limits the output current to a value that is safe for the power supply. Some unregulated states occur so briefly that
they do not turn on the Unr annunciator, but they may set the UNR status bit during remote operation (see the power supply
“Programming Guide”). One condition that can cause a noticeable unregulated state is low ac line voltage.

Saving and Recalling Operating States

You can save programming time by storing up to 5 (up to 4 with Series 668xA supplies) operating states in nonvolatile
memory. The front panel programming parameters that are saved are:

n Output voltage, Output current, OVP voltage.

n OCP state (on or off), Output state (enabled or disabled).

Note More power supply parameters are saved in remote operation. See the power supply “Programming Guide”.

As an example, set up the following state:

n Voltage = 4 V Current = 5 A OVP voltage = 4.5 V.

n OCP = on (OCP annunciator on) Output = off (Dis annunciator on).

Save the above state to location 1 by pressing . Now set up the following state:

n Voltage = 4.5 V Current = 2.5 A OVP voltage = 5 V.

n OCP = off (OCP annunciator off) Output = on (Dis annunciator off).

Save the above state to location 2 by pressing .

Restore the first state by pressing and verify the parameters. Restore the second state by pressing
. Note how the power supply is automatically programmed each time.

Turn-On Conditions
Whenever you apply power to a new power supply it automatically turns on in a safe reset state with the following
parameters:

off 0 minimum* maximum off

*Minimum is the *RST value specified in Table 3-1 in the Programming Guide.

It is recommended that you leave the turn-on conditions as programmed. However, you may change them if you wish. To do
this, proceed as follows:

1. Set up the power supply to the state you want when it is turned on.
2. Store that state to location 0.
3. Turn off the power supply.
4. Hold in the key and turn the power supply back on. The display indicates RCL 0 PWR-ON to verify that the power
supply has configured its turn-on state to that stored in location 0.
5. From now on the supply will always turn on to the state defined in location 0.

92 Front Panel Operation

Whenever you wish, you can return the power supply to the original factory reset state. To do this, simply hold down the
key when you turn on the supply. The display indicates RST POWER-ON to verify that the power supply has configured
its turn-on state to the original reset state. From now on it will continue to turn on in that state.

Setting the GPIB Address

Types of Power Supply GPIB Addresses

Figure 4-6 in Chapter 4 shows the ways the power supply can be connected to the GPIB bus. You can set up the GPIB
address in one of three ways:

1. As a stand-alone supply (the only supply at the address). It has a primary address in the range of 0 to 30. For example: 5
or 7.

2. As the direct supply in a serial link. It is the only supply connected directly to the GPIB bus. The primary address is
unique and can be from 0 to 30. It is entered as an integer followed by a decimal separator. The secondary address always
is 0, which may be added after the primary address. If the secondary address is omitted, it is assumed to be 0. For
example: 5.0 or 7.

3. As a linked supply in serial link. It gets its primary address from the direct supply. It has a unique secondary address that
can be from l to 15. It is entered as an integer preceded by a decimal separator. For example: .l or .12

When you enter a secondary address, leading zeros between the decimal separator and the first digit are ignored. For
example, .1, .01, and .001 are accepted as secondary address 1 and displayed as 0.01. Zeros following a digit are not
ignored. Thus, .10 and .010 are both accepted as secondary address 10 and displayed as 0. 10.

Changing the Power Supply GPIB Address

Use the key and numerical keypad for entering addresses. The power supply is shipped with a 5 stand-alone
address as the default. The general procedure for setting an address is:

Action Display Shows

Press Current address
Press new address keys New address replaces numbers on the display
Press Display returns to meter mode

If you try to enter a forbidden number, ADDR ERROR is displayed.

The following examples show how to set addresses:

To set stand-along primary address 6, press .

To set direct supply primary address 6, press .
To set linked secondary address 1, press .
To set linked secondary address 12, press .

Note The power supply display will reset (recall the state in location 0) whenever you change between the
following types of GPIB addresses:
• a stand-alone primary address and a direct primary address.
• a direct primary address and a secondary address.

Front Panel Operation 93

 A
Calibration

Introduction
The power supply may be calibrated either from the front panel or from a controller over the GPIB. The procedures given
here apply to all models.

Important These instructions do not include verification procedures. If you need to perform verification as a
prerequisite to or as part of your calibration procedure, see “Appendix B - Verification”.

Equipment Required
The equipment listed in Table A-1, or equivalent, is required for calibration.

Table A-1. Equipment Required for Calibration

Equipment Characteristics Recommended Model
Voltmeter D-c accuracy 0.005%, 6 digits Agilent 3456A or 3458A
Shunt resistor
Agilent 6641A, 51A, 52A 100 A, 0.01 Ω, 0.04%, 100 W Guildline 9230/100
Agilent 6642A, 43A, 44A, 45A, 15 A, 0.1 Ω, 0.04%, 25 W Guildline 9230/15
6653A, 54A, 55A
Agilent 6671A 300 A, 0.001 Ω, 0.04%,100 W Guildline 9230/300
Agilent 6672A, 73A, 74A, 75A 300 A, 0.001 Ω, 0.04%, 100 W Guildline 9230/300
Agilent 6680A, 81A, 6690A 1000 A, 0.1 mΩ, 0.05% Burster 1280S
Agilent 6682A, 83A, 84A, 300 A, 0.001 Ω, 0.04%,100 W Guildline 9230/300
6691A, 92A
For Calibration Over the GPIB
GPIB Controller IBM compatible PC with GPIB Interface

General Procedure

Because the power supply output must be enabled during calibration, voltages or currents
hazardous to personnel and/or damaging to equipment can appear at the output terminals.

ENERGY HAZARD. Series 668xA/669xA supplies can provide more than 240 VA at more than 2
V. If the output connections touch, severe arcing may occur resulting in burns, ignition or welding of
parts. Do not attempt to make connections to live output circuits.

Parameters Calibrated
The following parameters may be calibrated:
• Output voltage.
• Output voltage readback.

Calibration 95
• Overvoltage protection (OVP).
• Output current.
• Output current readback.
• Current monitor input IM (Series 668xA/669xA only).

You do not have to do a complete calibration each time. If appropriate, you may calibrate only the voltage or current and
proceed to "Saving the Calibration Constants". However, for Series 668xA/669xA supplies, the following sequences must
be followed:

• Calibrate voltage before OVP.

• Calibrate the current monitor input before current output.

Test Setup
Figure A-1 shows the test setups required for voltage and current calibration for each power supply series.

Front Panel Calibration

Eight shifted keys and the Entry keypad are used for calibration functions (see "Chapter 5 - Front Panel Operation” for
explanations of shifted keys and the Entry keypad). The following procedures assume you understand how to operate front
panel keys.

Entering the Calibration Values

Follow the steps in Table A-2 for entering calibration values.

Saving the Calibration Constants

Storing calibration constants overwrites the existing ones in nonvolatile memory. If you are not
absolutely sure you want to permanently store the new constants, omit this step. The power supply
calibration will then remain unchanged.

To replace any existing calibration constants with ones you have just entered, press .
CAL SAVED then appears on the display.

Disabling the Calibration Mode

To disable the calibration mode, press . The display will return to meter mode with the Cal annunciator off.

Changing the Calibration Password

The factory default password is the model number of your supply, such as 6671. You can change the calibration password
only when the power supply is in the calibration mode (which requires you to enter the existing password). Proceed as
follows:

1. Press .
2. Enter the new password from the keypad. (You can use up to six integers and an optional decimal point.) If you want
to operate without requiring any password, change the password to 0 (zero).
3. AGAIN will appear on the display. Enter the password a second time.
4. When OK is displayed, the new password has been accepted.

96 Calibration
c) Series 668xA/669xA Setup

Figure A-1. Calibration Test Setup

Calibration 97
 Table A-2. Typical Front Panel Calibration Procedure
Action Display Response

Enabling the Calibration Mode

1. Begin calibration by pressing . PASWDl
2. Enter calibration password from Entry keypad.
If password is correct the Cal annunciator will come on.
If password is incorrect, an error occurs2. PASSWD ERROR
Note: The initial (factory-default) password is the model number of the power supply,
but it can be changed (see "Changing the Password" in Appendix A - Calibration).
Entering Voltage Calibration Values
1. Make certain the DVM is the only load on the power supply. (Meter mode)
2. Select the first calibration point by pressing . VRDG1
If the power supply is not in CV mode, an error occurs3 WRONG MODE
3. Read the DVM and use the Entry keypad to enter the first voltage value. (Meter mode)
4. Select the second calibration point by pressing again. VRDG2
5. Read the DVM and use the Entry keypad to enter the second voltage value. (Meter mode)
Note: If one of the entered values is not within acceptable range, an error occurs.
The power supply is now holding the new voltage calibration constants in RAM. CAL ERROR

Calibrating the OVP Trip Point

1. Make certain the voltage has been calibrated and there is no load on the power supply. (Meter mode)
2. Select OVP calibration by pressing . OVPCAL
3. Wait for the power supply to compute the OVP calibration constant. CAL COMPLETE
If the supply goes unregulated or into CC mode during OVP calibration, an error occurs. NOT CV MODE
If the computed constant is out of acceptable range, an error occurs. DOES NOT CAL
Wait for the power supply to compute the new OVP calibration constants, which will be
stored in RAM.

Entering Current Calibration Values

1. Make certain appropriate shunt resistor (see Table A-l) is the only load on the power supply. (Meter mode)
2. Select the first calibration point by pressing . IRDG1
If the power supply is not in CC mode, an error occurs.4 WRONG MODE
3. Wait for DVM reading to stabilize. Then read DVM and compute the first current value (Meter mode)
(DVM reading ÷ shunt resistance).
4. Use Entry keypad to enter the first current value. (Meter mode)
5. Select second calibration point by pressing again. IRDG2
6. Wait for DVM reading to stabilize. Then read DVM and compute the second (Meter mode)
current value (DVM reading ÷ shunt resistance).
7. Use Entry keypad to enter the second current value. (Meter mode)
Note: If the entered value is not within acceptable range, an error occurs. CAL ERROR
The power supply is now holding the new current calibration constant in RAM. CAL COMPLETE

1.
If CAL DENIED appears, then an internal jumper has been set to prevent the calibration from being changed. (See the
Service Manual.)
2.
If the active password is lost, the calibration function can be recovered by moving an internal jumper that defeats
password protection. However, this also will change all calibration constants to their factory-default values. (For more
information, see the Service Manual.)
3.
Program the output current to 10% of its rated output*
4.
Program the output voltage to l0% of its rated output*
* See applicable Output Ratings in "Chapter 1- General Information"

98 Calibration
 Table A-2. Typical Front Panel Calibration Procedure (continued)
Action Display Response

Calibrating Current Monitor (IM) (Series 668xA/669xA Only)

If you perform this calibration, then you must recalibrate the current output.
1. Make certain the appropriate shunt resistor (see Table A-1) is the only load on the power (Meter mode)
supply.
2. Select IMN calibration by pressing IMON CAL
If the power supply is not in CC mode, an error occurs.4 WRONG MODE
3. Wait for DVM reading to stabilize. Then read DVM and compute the current value (Meter mode)
(DVM reading ÷ shunt resistance).
4. Use Entry keypad to enter the current value. (Meter mode)
Note: If the entered value is not within acceptable range, an error occurs. CAL ERROR
Wait for the power supply to compute the new current calibration constants, which will be CAL COMPLETE
stored in RAM.
If the constant is not within acceptable range, an error occurs. CAL ERROR

4.
Program the output voltage to 10% of its rated output*
*See applicable Output Ratings in “Chapter 1- General Information”

Recovering From Calibration Problems

You can encounter serious calibration problems if you cannot determine a calibration password that has been changed or the
power supply is severely out of calibration. There are jumpers inside the power supply that permit the calibration password
to be defeated and allow the original factory calibration constants to be restored. These jumpers are explained in the Service
Manual.

Calibration Error Messages

Error messages that can occur during calibration are shown in Table A-3.

Table A-3. GPIB Calibration Error Messages

Error Meaning Error Meaning
No. No.
1 CAL jumper prevents calibration1 6 Wrong CAL command sequence
2 CAL password is incorrect 7 Incorrect state (CV/CC) for this command
3 CAL mode is not enabled
4 Incorrect computed readback constants
1
5 Incorrect computed programming This is a hardware disable. See the power supply
constants Service Manual.

Calibration 99
Calibration Over the GPIB
You can calibrate the power supply by using SCPI commands within your controller programming statements. Be sure you
are familiar with calibration from the front panel before you calibrate from a controller. The SCPI calibration commands are
related to the front panel calibration controls as follows:

Front Panel Corresponding SCPI Front Panel Corresponding SCPI

Command Command Command Command
CAL:STAT {ON|1},<password> CAL:VOLT:PROT

CAL:STAT {OFF|0} CAL:CURR:LEV {MIN|MAX}

CAL:CURR[:DATA] <NRf>
CAL:PASS <NRf> CAL:CURR:MON<newline>
CAL:CURR:DATA <NRf>
CAL:VOLT:LEV {MIN|MAX} CAL:SAVE
CAL:VOLT[:DATA] <NRf>

A sample calibration program is given at the end of this appendix. If your system is Agilent BASIC, you can use the
program with very little modification. Otherwise, use it as a guide for writing your own program.

Calibration Language Dictionary

The calibration commands are listed in alphabetical order. The format for each command follows that shown in "Chapter 3 -
Language Dictionary" of the Programming Guide. Calibration error messages that can occur during GPIB calibration are
shown within this guide (Table A-3 in Appendix A - Calibration).

CAL:CURR
This command is used to calibrate the output current. The command enters current value that you obtain from an external
meter. (If you are entering the current value, allow time for the DVM to stabilize.) You must first select a calibration level
(CAL:CURR:LEV) for the value being entered. Two successive values (one for each end of the calibration range) must be
selected and entered. The power supply then computes new current calibration constants. These constants are not stored in
nonvolatile memory until saved with the CAL:SAVE command.

Command Syntax CALibrate:CURRent[:DATA] <NRf>

Parameters (See applicable Output Ratings specification in "Chapter 1- General Information")
Default Suffix A
Examples CAL: CURR 32 . 33 A CAL: CURR: DATA 5 . 00
Query Syntax (None)
Related Commands CAL:SAVE CAL:STAT

CAL:CURR:LEV
This command sets the power supply to a calibration point that is then entered with CAL:CURR[:DATA]. During
calibration, two points must be entered and the low-end point (MIN) must be selected and entered first.

Command Syntax CALibrate:CURRent:LEVel {MIN|MAX}

Parameters {<CRD>|MINimum|MAXimum}
Examples CAL: CURR: LEV MIN CAL: CURR: LEV MAX
Query Syntax (None)
Related Commands CAL:CURR[:DATA] CAL:STAT

100 Calibration
CAL:CURR:MON (Series 668xA/669xA only)
This command sets the power supply to the current monitor (IMON) calibration point that is then entered with
CAL:CURR[:DATA]. The output current must be calibrated after CAL:CURR:MON is performed.

Command Syntax CALibrate:CURRent:MONitor

Parameters <NRf+>
Examples CAL: CURR: MON CALibrate: CURRent: MONitor
Query Syntax (None)
Related Commands CAL:CURR[:DATA] CAL:STAT

CAL:PASS
This command enters a new calibration password. The command is active only when the power supply is already in the
calibration mode. Unless it is changed subsequently to shipment, the password is the power supply's four-digit model
number. If the password is set to 0, password protection is removed and CAL:STAT ON is unrestricted. A new password is
automatically stored in nonvolatile memory and does not have to be stored with the CAL:SAVE command.

Command Syntax CALibrate:PASScode <NRf>

Parameters <NRf>
Examples CAL:PASS 6671 CAL:PASS 09.1993
Query Syntax (None)
Related Commands CAL:STAT

CAL:SAVE
This command saves any new calibration constants (after a current or voltage calibration procedure has been completed) in
nonvolatile memory.

Command Syntax: CALibrate:SAVE

Parameters (None)
Examples CAL: SAVE
Query Syntax (None)
Related Commands CAL:CURR CAL:VOLT CAL:STAT

CAL:STAT
This command enables and disables the calibration mode. The calibration mode must be enabled before the power supply
will accept any other calibration commands. The first parameter specifies the enabled or disabled state. The second
parameter is the password. It is required if the calibration mode is being enabled and the existing password is not 0. If the
second parameter is not entered or is incorrect, an error is generated and the calibration mode remains disabled. The query
statement returns only the state, not the password.

Whenever the calibration mode is changed from enabled to disabled, any new calibration constants are lost unless they have
been stored with CAL:SAVE.

Command Syntax: CALibrate:STATe <bool> [,<NRf>]

Parameters {0 | OFF} | {1 | ON} [,<NRf>]
*RST Value OFF
Examples CAL:STAT 1,6671 CAL:STAT OFF
Query Syntax CALibrate:STATe?
Returned Parameters {0 | 1 }
Related Commands CAL:PASS CAL:SAVE

Calibration 101
CAL:VOLT
This command is used to calibrate the output voltage. The command enters voltage value that you obtain from an external
meter. (If you are entering the voltage value, allow time for the DVM to stabilize.) You must first select a calibration level
(CAL:VOLT:LEV) for the value being entered. Two successive values (one for each end of the calibration range) must be
selected and entered. The power supply then computes new voltage calibration constants. These constants are not stored in
nonvolatile memory until saved with the CAL:SAVE command.

Command Syntax CALibrate:VOLTage[:DATA] <NRf>

Parameters (See applicable Output Ratings in "Chapter 1- General Information")
Default Suffix A
Examples CAL: VOLT 322 . 5 MV CAL: VOLT: DATA 3 . 225
Query Syntax (None)
Related Commands CAL:SAVE CAL:STAT

CAL:VOLT:LEV

This command sets the power supply to a calibration point that is then entered with CAL:VOLT[:DATA]. During
calibration, two points must be entered and the low-end point (MIN) must be selected and entered first.

Command Syntax CALibrate:VOLTage:DATA {MIN|MAX}

Parameters { < CRD > | MINimum | MAXimum}
Examples CAL: VOLT: LEV MIN CAL: VOLT: LEV MAX
Query Syntax (None)
Related Commands CAL:VOLT[:DATA] CAL:STAT

CAL:VOLT:PROT
This command calibrates the power supply overvoltage protection (OV) circuit. The output voltage must be in calibration
before this procedure is performed. Also, the power supply output must be enabled and operating in the constant voltage
(CV) mode. If present, the optional relay accessory must either be disconnected or set to the off (open) state. The power
supply automatically performs the calibration and stores the new OV constant in nonvolatile memory. CAL:VOLT:PROT
is a sequential command that takes several seconds to complete.

Command Syntax: CALibrate:VOLTage:PROTection

Parameters (None)
Example CAL: VOLT: PROT
Query Syntax (None)
Related Commands CAL:STAT

Agilent BASIC Calibration Program

The following program can be run on any controller operating under Agilent BASIC. The assumed power supply address is
5 and calibration password is 6680. If required, change these parameters in the appropriate statements.

Note If you are calibrating models 664x, 665x, or 667x, delete or comment out lines 640 through 670 in the
following calibration program. These program lines are only required when calibrating models 668x/669x.

102 Calibration
10 ! Agilent BASIC Calibration Program
20 !
30 DIM Resp$ [255],Err_msg$[255]
40 !
50 Volt_cal: ! Voltage DAC calibration
60 Err_found=0
70 PRINT TABXY(5,10),"CONNECT INSTRUMENTS AS SHOWN IN FIG. A-1(1). Then Press Continue"
80 PAUSE
90 CLEAR SCREEN
100 !
110 ! Assign power supply GPIB address
120 !
130 ASSIGN @Ps TO 705
140 !
150 ! Initialize power supply
160 !
170 OUTPUT @Ps;"*RST;OUTPUT ON"
180 !
190 ! Password is optional - only required if set to non-zero value
200 ! Default password is the four-digit model number
210 !
220 ! LINE 240 PASSWORD MUST BE EDITED FOR MODEL OTHER THAN 6680
230 !
240 OUTPUT @Ps;"CAL:STATE ON, 6680"
250 1
260 OUTPUT @Ps;"CAL:VOLTAGE:LEVEL MIN"
270 INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read
280 OUTPUT @Ps;"CAL:VOLTAGE ";Volt_read
290 OUTPUT @Ps;"CAL:VOLTAGE:LEVEL MAX"
300 INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read
310 OUTPUT @Ps;"CAL:VOLTAGE ";Volt_read
320 !
330 ! Calibrate overvoltage protection circuit
340 !
350 OUTPUT @Ps;"CAL:VOLTAGE:PROTECTION"
360 !
370 GOSUB Save_cal
380 IF Err_found THEN
390 INPUT "ERRORS have occurred, REPEAT VOLTAGE CALIBRATION ( Y 0R N )?",Resp$
400 IF TRIM$(UPC$(Resp$[1,1] ) )="Y" THEN GOTO Volt_cal
410 END IF
420 IF Err_found THEN
430 PRINT "VOLTAGE CALIBRATION NOT SAVED"
440 ELSE
450 PRINT "VOLTAGE CALIBRATION COMPLETE"
460 END IF
470 !
480 Current_cal: ! Imon DAC and Current DAC calibration
490 Err_found=0
500 PRINT TABXY(5,10),"CONNECT INSTRUMENTS AS SHOWN IN FIG. A-1(2). Then Press Continue"
510 PAUSE
520 CLEAR SCREEN
Figure A-2. Agilent BASIC Calibration Program

Calibration 103
540 Password is optional - only required if set to non-zero value
550 Default password is four-digit model number
560 !
570 ! LINE 590 PASSWORD MUST BE EDITED FOR MODEL OTHER THAN 6680
580 !
590 OUTPUT @Ps;"CAL:STATE ON, 6680"
600 OUTPUT @Ps;"VOLT:LEV 2"
610 ! Refer to Table A-1 for correct shunt value for model being calibrated
620 !
630 INPUT "ENTER VALUE 0F CURRENT SHUNT BEING USED",Shunt_val
STEPS 640 THROUGH 670 NOT USED ON 664x, 665x and 667x
640 OUTPUT @Ps;"CAL:CURRENT:MONITOR"
650 INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read
660 Current=Volt_read/Shunt_val
670 OUTPUT @Ps;"CAL:CURRENT ";Current
680 OUTPUT @Ps;"CAL:CURRENT:LEVEL MIN"
690 INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read
700 Current=Volt_read/Shunt_val
710 OUTPUT @Ps;"CAL:CURRENT ";Current
720 OUTPUT @Ps;"CAL:CURRENT:LEVEL MAX"
730 INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read
740 Current=Volt_read/Shunt_val
750 OUTPUT @Ps;"CAL:CURRENT ";Current
760 GOSUB Save_cal
770 IF Err_found THEN
780 INPUT "ERRORS have occurred, REPEAT CURRENT CALIBRATION ( Y 0R N )?",Resp$
790 IF TRIM$(UPC$(Resp$[l,1] ))="Y" THEN GOTO Volt_cal
800 END IF
810 IF Err_found THEN
820 PRINT "CURRENT CALIBRATION NOT SAVED"
830 ELSE
840 PRINT "CURRENT CALIBRATION COMPLETE"
850 END IF
860 STOP
870 Save_cal: ! SAVE CALIBRATION
880 REPEAT
890 OUTPUT @Ps;"SYSTEM:ERROR?"
900 ENTER @Ps;Err_num,Err_msg$
910 IF Err_num< >0 THEN
920 PRINT "ERROR: ";Err_msg$
930 Err_found=1
940 END IF
950 UNTIL Err_num=0
960 IF NOT Err_found THEN
970 INPUT "SAVE CALIBRATION CONSTANTS ( Y 0R N )?",Resp$
980 IF TRIM$(UPC$(Resp$[l,1] ))="Y" THEN
990 OUTPUT @Ps;"CAL:SAVE"
1000 END IF
1010 END IF
1020 OUTPUT @Ps;"CAL:STATE OFF"
1030 RETURN
1040 END
Figure A-2. Agilent BASIC Calibration Program (continued)

104 Calibration
 B
Operation Verification

Introduction
This appendix provides operation verification test procedures. The tests do not check all the operating parameters, but
verify that the power supply is performing properly. The required test equipment and acceptable test results are specified in
tables at the end of this appendix.

Note Performance Tests, which check all the specifications of the power supply, are given in the applicable
power supply Service Manual.

Test Equipment Required

List of Equipment
The following equipment is required to perform the tests:

Table B-1. Equipment Required for Verification Tests

Equipment Characteristics Recommended Model

Digital Voltmeter Resolution: 10 nV @ 1 V Agilent 3458A

Readout: 8 1/2 digits
Accuracy: 20 ppm

Current Monitor Resistor

Agilent 6641A, 51A, 52A 100 A, 0.01 Ω, 0.04%, 100 W Guildline 9230/100

Agilent 6642A, 43A, 44A, 45A, 53A, 54A, 55A 15 A, 0.1 Ω, 0.04%, 25 W Guildline 9230/15

Agilent 6671A 300 A, 0.001 Ω, 0.04%, 100 W Guildline 9230/300

Agilent 6672A, 73A, 74A, 75A l00 A, 0.001 Ω, 0.04%, 100 W Guildline 9230/100

Agilent 6680A, 81A, 1000 A, 0.1 mΩ, 0.05% Burster 1280S

6690A
Agilent 6682A, 83A, 84A, 300 A, 0.001 Ω, 0.04%, 100 W Guildline 9230/300
6691A, 92A

Current Monitoring Resistor

The 4-terminal current-monitoring resistor listed in Table B-1 is required to eliminate output current measurement error
caused by voltage drops in leads and connections. The specified resistors have special current-monitoring terminals inside
the load connection terminals. Connect the current monitor directly to these current-monitoring terminals.

Operation Verification 105

 c) Series 668xA/669xA Setup

Figure B-1. Verification Test Setup

106 Operation Verification

Performing the Tests

General Measurement Techniques

Figure B-1 shows the setup for the tests. Be certain to use load leads of sufficient wire gauge to carry the output current (see
Table 4-1). To avoid noise pickup, use coaxial cable or shielded pairs for the test leads.

Programming the Power Supply

Table 1-lb, Table 1-2b, Table 1-3b and Table 1-4b in Chapter 1 list the programming voltage and current ranges for each
model. Enter the appropriate values from the front panel. The programming procedures assume you know how to operate
the power supply from the front panel (see "Chapter 5 - Front Panel Operation").

Order of Tests
Perform the following tests for operation verification. Test 1 must be done first, followed by Tests 2 and 3 in any order.

1 Turn-on Checkout
2 Voltage Programming and Readback Accuracy
3 Current Programming and Readback Accuracy

Turn-on Checkout
Perform the Turn-on Checkout as directed in "Chapter 3 - Turn-on Checkout".

Note The power supply must pass turn-on selftest before you can proceed with these tests.

Voltage Programming and Readback Accuracy

This test verifies that the voltage programming, GPIB readback, and front panel display functions are within specifications.
Figure B-1 shows the setup for the tests. Measure the dc output voltage directly at the sense connections of the output
terminals or bus bars. Connect the output as shown.

Table B-2. Voltage Programming and Readback Accuracy Tests

Action Normal Result
1 Turn off the power supply and connect a DVM across the
sense terminals (see Figure B-1(1)).

2 Turn on the power supply with no load and program the CV annunciator on. Output current near 0.
output for 0 volts and maximum programmable current.

3 Record voltage readings at DVM and on front panel Readings within Low Voltage limits (see applicable test
display. (Subtract or add the specified readback limit to table).
the actual output values).

4 Program voltage to full scale.

5 Record voltage readings of DVM and on front panel Readings within High Voltage limits (see applicable test
display. (Subtract or add the specified readback limit to table).
the actual output values)

Operation Verification 107

Current Programming and Readback Accuracy
This test verifies that the current programming and readback are within specification. Connect the appropriate current
monitoring resistor (see Table B-1) as shown in Figure B-1(2). The accuracy of the resistor must be as specified in the table.

Table B-3. Current Programming and Readback Accuracy Test

Action Normal Result
1 Turn off the power supply and connect the current monitoring
resistor as shown in Figure B-1(2). Be certain to use wire of
sufficient size to carry the maximum rated current of the
supply (see Table 4-1 in Chapter 4).

2 Connect a DVM across the resistor.

3 Turn on the power supply and program the output for 5 volts
and 0 amperes.

4 Disable the output ( )

WARNING
ENERGY HAZARD for Series 668xA/669xA. The power supply can provide more than 240 VA at more than 2 V.
If the output connections touch, severe arcing may occur resulting in burns, ignition or welding of parts. Do not
attempt to make connections to live output circuits.

5 Enable the output or OUTP ON).

6 Observe the DVM voltage reading. Divide this by the Value within Low Current limits (see applicable test
resistance of the current monitor resistor. Record the result as table).
the Low Current value in applicable test table.

7 Record the front panel display readback Value within specified readback limits (see
applicable test table).

8 Program output current to full scale.

9 Repeat Steps 6 and 7. Both current readings within specified High Current
and readback limits (see applicable test table).

10 Disable the output ( ).

11 Remove the short from across the load.

108 Operation Verification

 Table B-4. Operation Verification Test Parameters for Series 664xA
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6641A
Voltage Programming and Readback
Low Voltage (0 V) Vout -5 mV ____________ mV + 5 mV 2.0 µV
Front Panel Display Readback Vout -6.0 mV ____________ mV Vout +6.0 mV 2.0 µV
High Voltage (8 V) Vout 7.990 V _____________V 8.010 V 88 µV
Front Panel Display Readback Vout -11.6 mV ____________ mV Vout +11.6 mV 88 µV
Current Programming and Readback
Low Current (0 A) Iout -26 mA ____________ mA +26 mA 153 µA
Front Panel Display Readback Iout -18 mA ____________ mA Iout +18 mA 153 µA
High Current (20 A) Iout 19.944 A ____________ A +20.056 A 2.7 mA
Front Panel Display Readback Iout -48 mA ____________ mA Iout +48 mA 2.7 mA
MODEL Agilent 6642A
Voltage Programming and Readback
Low Voltage (0 V) Vout -10 mV ____________ mV + 10 mV 2.0 µV
Front Panel Display Readback Vout -15 mV ____________ mV Vout +15 mV 2.0 µV
High Voltage (20 V) Vout 19.978 V _____________V 20.022 V 335 µV
Front Panel Display Readback Vout -29 mV ____________ mV Vout +29 mV 335 µV
Current Programming and Readback
Low Current (0 A) Iout -13 mA ____________ mA +13 mA 20 µA
Front Panel Display Readback Iout -9.1 mA ____________ mA Iout +9.1 mA 20 µA
High Current (10 A) Iout 9.972 A ____________ A +10.028 A 3.1 mA
Front Panel Display Readback Iout -24.1 mA ____________ mA Iout +24.1 mA 3.1 mA
MODEL Agilent 6643A
Voltage Programming and Readback
Low Voltage (0 V) Vout -15 mV ____________ mV + 15 mV 2.0 µV
Front Panel Display Readback Vout -25 mV ____________ mV Vout +25 mV 2.0 µV
High Voltage ( 35 V) Vout 34.964 V _____________V 35.036 V 525 µV
Front Panel Display Readback Vout -50 mV ____________ mV Vout +50 mV 525 µV
Current Programming and Readback
Low Current (0 A) Iout -6.7 mA ____________ mA +6.7 mA 16 µA
Front Panel Display Readback Iout -5 mA ____________ mA Iout +5 mA 16 µA
High Current ( 6 A) Iout 5.985 A ____________ A 6.015 A 1.1 mA
Front Panel Display Readback Iout -14 mA ____________ mA Iout +14 mA 1.1 mA
MODEL Agilent 6644A
Voltage Programming and Readback
Low Voltage (0 V) Vout -26 mV ____________ mV + 26 mV 2.0 µV
Front Panel Display Readback Vout -40 mV ____________ mV Vout +40 mV 2.0 µV
High Voltage ( 60 V) Vout 59.938 V _____________V 60.062 V 845 µV
Front Panel Display Readback Vout -82 mV ____________ mV Vout +82 mV 845 µV
Current Programming and Readback
Low Current (0 A) Iout -4.1 mA ____________ mA +4.1 mA 16 µA
Front Panel Display Readback Iout -3 mA ____________ mA Iout +3 mA 16 µA
High Current (3.5 A) Iout 3.491 A ____________ A +3.509 A 500 µA
Front Panel Display Readback Iout -8.3 mA ____________ mA Iout +8.3 mA 500 µA

* Enter your test results in this column.

Operation Verification 109

 Table B-4. Operation Verification Test Parameters for Series 664xA (continued)
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6645A
Voltage Programming and Readback
Low Voltage (0 V) Vout -51 mV ____________ mV + 51 mV 2.0 µV
Front Panel Display Readback Vout -80 mV ____________ mV Vout +80 mV 2.0 µV
High Voltage (120 V) Vout 119.877 V _____________V 120.123 V 1.7 mV
Front Panel Display Readback Vout -164 mV ____________ mV Vout +164 mV 1.7 mV
Current Programming and Readback
Low Current (0 A) Iout -1.7 mA ____________ mA +1.7 mA 16 µA
Front Panel Display Readback Iout -1.3 mA ____________ mA Iout +1.3 mA 16 µA
High Current (1.5 A) Iout 1.496 A ____________ A +1.504 A 188 µA
Front Panel Display Readback Iout -3.5 mA ____________ mA Iout +3.5 mA 188 µA
* Enter your test results in this column.

110 Operation Verification

 Table B-5. Operation Verification Test Parameters for Series 665xA
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6651A
Voltage Programming and Readback
Low Voltage (0 V) Vout -5 mV ____________ mV + 5 mV 2.0 µV
Front Panel Display Readback Vout -6.0 mV ____________ mV Vout +6.0 mV 2.0 µV
High Voltage (8 V) Vout 7.990 V _____________V 8.010 V 88 µV
Front Panel Display Readback Vout -11.6 mV ____________ mV Vout +11.6 mV 88 µV
Current Programming and Readback
Low Current (0 A) Iout -60 mA ____________ mA +60 mA 150 µA
Front Panel Display Readback Iout -67 mA ____________ mA Iout +67 mA 150 µA
High Current (50 A) Iout 49.865 A ____________ A +50.135 A 10.7 mA
Front Panel Display Readback Iout -142 mA ____________ mA Iout +142 mA 10.7 mA
MODEL Agilent 6652A
Voltage Programming and Readback
Low Voltage (0 V) Vout -10 mV ____________ mV + 10 mV 2.0 µV
Front Panel Display Readback Vout -15 mV ____________ mV Vout +15 mV 2.0 µV
High Voltage (20 V) Vout 19.978 V _____________V 20.022 V 335 µV
Front Panel Display Readback Vout -29 mV ____________ mV Vout +29 mV 335 µV
Current Programming and Readback
Low Current (0 A) Iout -25 mA ____________ mA +25 mA 153 µA
Front Panel Display Readback Iout -26 mA ____________ mA Iout +26 mA 153 µA
High Current (25 A) Iout 24.937 A ____________ A +25.063 A 3.5 mA
Front Panel Display Readback Iout -63.5 mA ____________ mA Iout +63.5 mA 3.5 mA
MODEL Agilent 6653A
Voltage Programming and Readback
Low Voltage (0 V) Vout -15 mV ____________ mV + 15 mV 2.0 µV
Front Panel Display Readback Vout -25 mV ____________ mV Vout +25 mV 2.0 µV
High Voltage ( 35 V) Vout 34.964 V _____________V 35.036 V 525 µV
Front Panel Display Readback Vout -50 mV ____________ mV Vout +50 mV 525 µV
Current Programming and Readback
Low Current (0 A) Iout -13 mA ____________ mA +13 mA 17 µA
Front Panel Display Readback Iout -15 mA ____________ mA Iout +15 mA 17 µA
High Current ( 15 A) Iout 14.964 A ____________ A 15.036 A 6.2 mA
Front Panel Display Readback Iout -37.5 mA ____________ mA Iout +37.5 mA 6.2 mA
MODEL Agilent 6654A
Voltage Programming and Readback
Low Voltage (0 V) Vout -26 mV ____________ mV + 25 mV 2.0 µV
Front Panel Display Readback Vout -40 mV ____________ mV Vout +40 mV 2.0 µV
High Voltage ( 60 V) Vout 59.938 V _____________V 60.062 V 845 µV
Front Panel Display Readback Vout -82 mV ____________ mV Vout +82 mV 845 µV
Current Programming and Readback
Low Current (0 A) Iout -8 mA ____________ mA +8 mA 16 µA
Front Panel Display Readback Iout -7 mA ____________ mA Iout +7 mA 16 µA
High Current (9 A) Iout 8.978 A ____________ A +9.022 A 2.5 mA
Front Panel Display Readback Iout -20.5 mA ____________ mA Iout +20.5 mA 2.5 mA
* Enter your test results in this column.

Operation Verification 111

 Table B-5. Operation Verification Test Parameters for Series 665xA (continued)
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6655A
Voltage Programming and Readback
Low Voltage (0 V) Vout -51 mV ____________ mV + 51 mV 2.0 µV
Front Panel Display Readback Vout -80 mV ____________ mV Vout +80 mV 2.0 µV
High Voltage (120 V) Vout 119.877 V _____________V 120.123 V 1.7 mV
Front Panel Display Readback Vout -164 mV ____________ mV Vout +164 mV 1.7 mV
Current Programming and Readback
Low Current (0 A) Iout -4 mA ____________ mA +4 mA 15 µA
Front Panel Display Readback Iout -3 mA ____________ mA Iout +3 mA 15 µA
High Current (4 A) Iout 3.990A ____________ A +4.010 A 586 µA
Front Panel Display Readback Iout -9 mA ____________ mA Iout +9 mA 586 µA
* Enter your test results in this column.

112 Operation Verification

 Table B-6. Operation Verification Test Parameters for Series 667xA
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6671A
Voltage Programming and Readback
Low Voltage (0 V) Vout -8 mV ____________ mV + 8 mV 1.6 µV
Front Panel Display Readback Vout -12 mV ____________ mV Vout +12 mV 1.6 µV
High Voltage (8 V) Vout 7.9888 V _____________V 8.0012 V 100 µV
Front Panel Display Readback Vout -16 mV ____________ mV Vout +16 mV 100 µV
Current Programming and Readback
Low Current (0 A) Iout -125 mA ____________ mA +125 mA 50 µA
Front Panel Display Readback Iout -150 mA ____________ mA Iout +150 mA 50 µA
High Current (220 A) Iout 219.655 A ____________ A 220.345 A 92 mA
Front Panel Display Readback Iout -370 mA ____________ mA Iout +370 mA 92 mA
MODEL Agilent 6672A
Voltage Programming and Readback
Low Voltage (0 V) Vout -20 mV ____________ mV + 20 mV 2.0 µV
Front Panel Display Readback Vout -30 mV ____________ mV Vout +30 mV 2.0 µV
High Voltage (20 V) Vout 19.972 V _____________V 20.028 V 335 µV
Front Panel Display Readback Vout -40 mV ____________ mV Vout +40 mV 335 µV
Current Programming and Readback
Low Current (0 A) Iout -60 mA ____________ mA +60 mA 40 µA
Front Panel Display Readback Iout -100 mA ____________ mA Iout +100 mA 40 µA
High Current (100 A) Iout 99.84 A ____________ A +100.16 A 41 mA
Front Panel Display Readback Iout -200 mA ____________ mA Iout +200 mA 41 mA
MODEL Agilent 6673A
Voltage Programming and Readback
Low Voltage (0 V) Vout -35 mV ____________ mV + 35 mV 2.0 µV
Front Panel Display Readback Vout -50 mV ____________ mV Vout +50 mV 2.0 µV
High Voltage ( 35 V) Vout 34.951 V _____________V 35.049 V 526 µV
Front Panel Display Readback Vout -68 mV ____________ mV Vout +68 mV 526 µV
Current Programming and Readback
Low Current (0 A) Iout -40 mA ____________ mA +40 mA 31 µA
Front Panel Display Readback Iout -60 mA ____________ mA Iout +60 mA 31 µA
High Current ( 60 A) Iout 59.9 A ____________ A 60.1 A 25 mA
Front Panel Display Readback Iout -120 mA ____________ mA Iout +120 mA 25 mA
MODEL Agilent 6674A
Voltage Programming and Readback
Low Voltage (0 V) Vout -60 mV ____________ mV + 60 mV 2.2 µV
Front Panel Display Readback Vout -90 mV ____________ mV Vout +90 mV 2.2 µV
High Voltage ( 60 V) Vout 59.916 V _____________V 60.084 V 1 mV
Front Panel Display Readback Vout -132 mV ____________ mV Vout +132 mV 1 mV
Current Programming and Readback
Low Current (0 A) Iout -25 mA ____________ mA +25 mA 21 µA
Front Panel Display Readback Iout -35 mA ____________ mA Iout +35 mA 21 µA
High Current (35 A) Iout 34.94 A ____________ A 35.06 A 15 mA
Front Panel Display Readback Iout -70 mA ____________ mA Iout +70 mA 15 mA
* Enter your test results in this column.

Operation Verification 113

 Table B-6. Operation Verification Test Parameters for Series 667xA (continued)
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6675A
Voltage Programming and Readback
Low Voltage (0 V) Vout -120 mV ____________ mV + 120 mV 3.0 µV
Front Panel Display Readback Vout -180 mV ____________ mV Vout +180 mV 3.0 µV
High Voltage (120 V) Vout 119.832 V _____________V 120.168 V 1.7 mV
Front Panel Display Readback Vout -240 mV ____________ mV Vout +240 mV 1.7 mV
Current Programming and Readback
Low Current (0 A) Iout -12 mA ____________ mA +12 mA 20 µA
Front Panel Display Readback Iout -18 mA ____________ mA Iout +18 mA 20 µA
High Current (18 A) Iout 17.97 A ____________ A +18.03 A 7.5 mA
Front Panel Display Readback Iout -36 mA ____________ mA Iout +36 mA 7.5 mA
* Enter your test results in this column.

114 Operation Verification

 Table B-7. Operation Verification Test Parameters for Series 668xA
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6680A
Voltage Programming and Readback
Low Voltage (0 V) Vout -0.005 V ____________ V + 0.005 V 1.0 µV
Front Panel Display Readback Vout -7.5 mV ____________ mV Vout +7.5 mV 1.0 µV
High Voltage (5 V) Vout 4.9943 V _____________V 5.0057 V 56 µV
Front Panel Display Readback Vout -10 mV ____________ mV Vout +10 V 56 µV
Current Programming and Readback
Low Current (0 A) Iout -0.450 A ____________ A +0.450 A 15 mA
Front Panel Display Readback Iout -600 mA ____________ mA Iout +600 mA 15 mA
High Current (875 A) Iout 873.675 A ____________ A +876.325 A 461 mA
Front Panel Display Readback Iout -1.475 A ____________ A Iout +1.475 A 461 mA
MODEL Agilent 6681A
Voltage Programming and Readback
Low Voltage (0 V) Vout -0.008 V ____________ V + 0.008 V 1.0 µV
Front Panel Display Readback Vout -12 mV ____________ mV Vout +12 mV 1.0 µV
High Voltage (8 V) Vout 7.9888 V _____________V 8.0112 V 88 µV
Front Panel Display Readback Vout -16 mV ____________ mV Vout +16 mV 88 µV
Current Programming and Readback
Low Current (0 A) Iout -0.300 A ____________ A +0.300 A 15 mA
Front Panel Display Readback Iout -400 mA ____________ mA Iout +400 mA 15 mA
High Current (580 A) Iout 579.12 A ____________ A +580.88 A 311 mA
Front Panel Display Readback Iout -980 mA ____________ mA Iout +980 mA 311 mA
MODEL Agilent 6682A
Voltage Programming and Readback
Low Voltage (0 V) Vout -21 mV ____________ mV + 21 mV 1.7 µV
Front Panel Display Readback Vout -32 mV ____________ mV Vout +32 mV 1.7 µV
High Voltage ( 21 V) Vout 20.970 V _____________V 21.030 V 348 µV
Front Panel Display Readback Vout -42 mV ____________ mV Vout +42 mV 348 µV
Current Programming and Readback
Low Current (0 A) Iout -125 mA ____________ mA +125 mA 1.5 mA
Front Panel Display Readback Iout -165 mA ____________ mA Iout +165 mA 1.5 mA
High Current ( 240 A) Iout 239.635 A ____________ A 240.365 A 83 mA
Front Panel Display Readback Iout -405 mA ____________ mA Iout +405 mA 83 mA
MODEL Agilent 6683A
Voltage Programming and Readback
Low Voltage (0 V) Vout -32 mV ____________ mV + 32 mV 1.9 µV
Front Panel Display Readback Vout -48 mV ____________ mV Vout +48 mV 1.9 µV
High Voltage ( 32 V) Vout 31.955 V _____________V 32.045 V 488 µV
Front Panel Display Readback Vout -64 mV ____________ mV Vout +64 mV 488 µV
Current Programming and Readback
Low Current (0 A) Iout -85 mA ____________ mA +85 mA 1.5 µA
Front Panel Display Readback Iout -60 mA ____________ mA Iout +60 mA 1.5 µA
High Current (160 A) Iout 159.755 A ____________ A 160.245 A 35.6 mA
Front Panel Display Readback Iout -270 mA ____________ mA Iout +270 mA 35.6 mA
* Enter your test results in this column.

Operation Verification 115

 Table B-7. Operation Verification Test Parameters for Series 668xA (continued)
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6684A
Voltage Programming and Readback
Low Voltage (0 V) Vout -40 mV ____________ mV + 40 mV 2.0 µV
Front Panel Display Readback Vout -60 mV ____________ mV Vout +60 mV 2.0 µV
High Voltage (40 V) Vout 39.944 V _____________V 40.056 V 590 µV
Front Panel Display Readback Vout -80 mV ____________ mV Vout +80 mV 590 µV
Current Programming and Readback
Low Current (0 A) Iout -65 mA ____________ mA +65 mA 1.5 mA
Front Panel Display Readback Iout -90 mA ____________ mA Iout +90 mA 1.5 mA
High Current (128 A) Iout 127.807 A ____________ A 128.193 A 24.1 mA
Front Panel Display Readback Iout -218 mA ____________ mA Iout +218 mA 24.1 mA
* Enter your test results in this column.

116 Operation Verification

 Table B-8. Operation Verification Test Parameters for Series 669xA
Test Description Minimum Spec Results * Maximum Measurement
Spec Uncertainty
MODEL Agilent 6690A
Voltage Programming and Readback
Low Voltage (0 V) Vout -0.015 V ____________ V + 0.015 V 1.0 µV
Front Panel Display Readback Vout -22.5 mV ____________ mV Vout +22.5 mV 1.0 µV
High Voltage (15 V) Vout 14.979 V _____________V 15.021 V 56 µV
Front Panel Display Readback Vout -30 mV ____________ mV Vout +30 mV 56 µV
Current Programming and Readback
Low Current (0 A) Iout -0.23 A ____________ A +0.23 A 15 mA
Front Panel Display Readback Iout -300 mA ____________ mA Iout +300 mA 15 mA
High Current (440 A) Iout 439.33 A ____________ A +440.67 A 461 mA
Front Panel Display Readback Iout -0.74 A ____________ A Iout +0.74 A 461 mA
MODEL Agilent 6691A
Voltage Programming and Readback
Low Voltage (0 V) Vout -0.030 V ____________ V + 0.030 V 1.0 µV
Front Panel Display Readback Vout -45 mV ____________ mV Vout +45 mV 1.0 µV
High Voltage (30 V) Vout 29.958 V _____________V 30.042 V 88 µV
Front Panel Display Readback Vout -60 mV ____________ mV Vout +60 mV 88 µV
Current Programming and Readback
Low Current (0 A) Iout -0.125 A ____________ A +0.125 A 15 mA
Front Panel Display Readback Iout -165 mA ____________ mA Iout +165 mA 15 mA
High Current (220 A) Iout 219.655 ____________ A +220.345 A 311 mA
Front Panel Display Readback Iout -385 mA ____________ mA Iout +385 mA 311 mA
MODEL Agilent 6692A
Voltage Programming and Readback
Low Voltage (0 V) Vout -60 mV ____________ mV + 60 mV 1.7 µV
Front Panel Display Readback Vout -90 mV ____________ mV Vout +90 mV 1.7 µV
High Voltage ( 60 V) Vout 59.916 V _____________V 60.084 V 348 µV
Front Panel Display Readback Vout -120 mV ____________ mV Vout +120 mV 348 µV
Current Programming and Readback
Low Current (0 A) Iout -65 mA ____________ mA +65 mA 1.5 mA
Front Panel Display Readback Iout -80 mA ____________ mA Iout +80 mA 1.5 mA
High Current ( 110 A) Iout 109.825 A ____________ A 110.175 A 83 mA
Front Panel Display Readback Iout -190 mA ____________ mA Iout +190 mA 83 mA
* Enter your test results in this column.

Operation Verification 117

 C
Line Voltage Conversion

Series 664xA and 665xA Power Supplies

SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been
turned off. This procedure should only be done by qualified electronics service personnel.

Line voltage conversion is accomplished by:

n Series 664xA - setting line voltage select switches.

n Series 665xA - changing wire and jumper positions on the ac input of the main power transformer.

Proceed as follows:

1. Turn off the ac power to the supply and disconnect the power cord from the power source.
2. Remove the four screws that secure the two carrying straps and outer cover.
3. Slightly spread the bottom rear of the cover and pull it back to disengage it from the front panel.
4. Slide the dustcover back far enough to expose the select switches (see Figure C-1) or the line select jumpers (see Figure
C-2).
5. On the Series 664xA supply, move the line voltage select switches to the positions corresponding to the desired line
voltage.
6. On the Series 665xA supply, move the line voltage select jumpers to the positions corresponding to the desired line
voltage. To disconnect it from the transformer tab, pull the wire straight up. Moving the wire from side-to-side can
damage the tab.
7. Replace the top cover and secure the carrying straps.
8. Change the line fuse (on the rear panel) to the proper value for the new line voltage (see Table 1-6 in Chapter 1).

Figure C-1. Series 664xA Line Select Switches

Line Voltage Conversion 119

 Figure C-2. Series 665xA Line Select Jumpers

Series 667xA Power Supplies

SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been
turned off. This procedure should only be done by qualified electronics service personnel.

Line voltage conversion is accomplished by setting a line voltage select switch. Proceed as follows:

1. Turn off the ac power and disconnect the power cord from the power source.
2. Remove the four screws securing the carrying straps and dustcover.
3. Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.
4. Slide the dustcover back far enough to expose the line select switch (see Figure C-3).
5. Observe the input rail LED under the RFI shield. If the LED is on, there is still hazardous voltage inside the supply.
Wait until the LED goes out (this may take several minutes) before proceeding.
6. Connect a dc voltmeter across test points TP1 and TP2. (It may be necessary to remove the RFI shield in order to reach
these test points. The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts or less, it is
safe to work inside the power supply.
7. Locate the line selector switch and slide it to the desired position.
8. If you removed it in step 6, be sure to replace the RFI shield.
9. Replace the dustcover.

Figure C-3. Series 667xA Line Select Switch

120 Line Voltage Conversion

Series 668xA/669xA Power Supplies

SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been
turned off. This procedure should only be done by qualified electronics service personnel.

Line voltage conversion is accomplished by changing jumper cable positions on the ac input of the main power transformer.
Proceed as follows:

1. Turn off the power switch and disconnect the power cord from the power source or turn off the power disconnect switch.
2. Remove the four screws that secure the two carrying straps and outer cover.
3. Slightly spread the bottom rear of the cover and pull it back to disengage it from the front panel.
4. Remove the outer cover by sliding it back towards the rear of the supply.
5. Observe the input rail LEDs under the inner cover (see Figure C-4). If the LEDs are on, there is still hazardous voltage
inside the supply. Wait until they both go out (this may take several minutes) before proceeding. (If one LED remains on
while the other goes out, the power supply probably has a defect that requires service.)

If you cannot see the LEDs through the hole in the inner cover, then wait until power has been removed
for at least 15 minutes before proceeding to the next step.

6. Remove the screws securing the inner cover (see Figure C-4).
7. Remove the inner cover.
8. Locate the three line conversion cables (A,B,C in Figure C-5). All three cables will be connected to the jacks that
correspond to one of the voltage ranges (1 or 2, Figure C-5).
9. Unplug the cables from their present jacks and plug them into the jacks for the other range.
10. Replace the inner cover.

Note Be sure to replace all of the screws removed in Step 6. All the screws are not needed for mechanical
security, but they are required to ensure proper magnetic shielding.

11. Replace the outer cover.

12. Remove the three fuses from the rear panel. If required, first remove the ac safety cover (see Figures 2-5 and 2-6).
13. Replace the fuses with the proper ones for the new range (see Table 1-6 in Chapter 1).
14. If required, replace the ac safety cover.

Reconnect the power and turn on the power supply.

Line Voltage Conversion 121

 Figure C-4. Removing the Series 668xA/669xA Inner Cover

Figure C-5. Series 668xA/669xA Line Conversion Jumpers

122 Line Voltage Conversion

 D
Digital Port Functions

Digital Connector

A 4-pin connector and a quick-disconnect mating plug are provided for digital input and output signals (see Figure D-l for
wiring connections, and Table 1-5 in Chapter 1 for electrical characteristics). This digital port can be configured to provide
either Fault/Inhibit or Digital I/O functions.

Note Consistent with good engineering practice, twist and shield all signal wires to and from the digital
connector.

Figure D-1. Digital Port Connector

Fault/Inhibit Operation
As shipped from the factory, the digital port is configured to provide a fault indicator (FLT) output and a remote (INH)
input. Unplug the mating plug to make the connections. After you have finished making all connections, plug the wired plug
back into the connector.

FLT Output Used to indicate that a fault has occurred in power supply. Pins 1 and 2 are the open collector
(pins 1 and 2) output of an optocoupler, with pin 1 the collector and pin 2 the emitter. When a fault has occurred,
pin 1 is driven low with respect to pin 2 (negative-true).
INH Input (pin 3) Used to shut down the power supply output. Pin 3 is a high impedance input. The supply shuts
down when this input is driven low (negative-true). This can be done by shorting pin 3 to pin 4.

INH Common Provides the common connection for the INH input.
(pin 4)

Three examples are provided to show how to use the FLT/INH circuits of your power supply. Use twisted wire connections
to reduce or prevent electromagnetic radiation in all cases. If shielded wire is used, connect only one end of the shield to the
chassis signal ground binding post to prevent ground loops.

Digital Port Functions 123

In Figure D-2, the INH input is connected to a switch that shorts pin 3 to pin 4 whenever it is necessary to externally disable
the output of the supply. This will activate the remote inhibit (RI) fault protection circuit, causing the front panel Prot
annunciator to come on. It also sets the RI event bit in the supply's Questionable Status Event register (see "Chapter 4 -
Status Reporting" in the Programming Guide). To re-enable the supply after it has been disabled by the INH input, first
open the connection between pins 3 and 4. Then clear the protection circuit either from the front panel (see "Chapter 5 -
Front Panel Operation" in this guide) or over the GPIB (see the Programming Guide).

GPIB

Figure D-2. Example of Inhibit Input

In Figure D-3A, the FLT output is connected to a relay driver circuit that energizes a relay whenever a fault condition
occurs in the power supply. The relay can be used to physically disconnect the output of the power supply from the load.
The FLT output is generated by the logical ORing of the power supply's Operation, Questionable, and Event status summary
bits (see "Chapter 4 - Status Reporting” in the Programming Guide). You can cause one or more events to activate the FLT
output by enabling the appropriate events in these status registers. The fault condition is cleared by first removing the cause
of the fault and then reading the appropriate status event register(s).

In Figure D-3B, the FLT output of one supply is connected to the INH input of another supply. Although only two supplies
are shown, it is possible to chain other supplies with this arrangement. A fault condition in any one of the power supplies
will disable all of them without intervention either by the controller or external circuitry. The controller can be made aware
of the fault via a service request (SRQ) generated by the Questionable Status summary bit (see "Chapter 4 - Status
Reporting" in the Programming Guide).

Note The INH input cannot be used to disable outputs set from the external voltage programming port.

124 Digital Port Functions

 GPIB GPIB

GPIB

Figure D-3. Examples of FLT Outputs

Figure D-4. Digital Port Configuration Jumper

Digital Port Functions 125

Changing the Port Configuration
As shipped from the factory, the digital port is configured for FLT/INH operation. You can change the configuration of the
port to operate as a general-purpose digital input/output port to control your custom circuitry as shown in Figure D-4. To
change the port configuration, you must move a jumper on the GPIB board.

Shock Hazard. Hazardous voltage can remain inside the power supply even after it has been turned off.
This procedure should only be done by qualified electronics service personnel.

Proceed as follows:
1. Turn off the power supply and disconnect the power cord from the power source or turn off the power disconnect switch
(Series 668xA/669xA).
2. Remove the four screws that secure the two carrying straps and outer cover.
3. Spread the bottom rear of the cover and pull it back to disengage it from the front panel.
4. Slide the outer cover back to expose the top of the GPIB board.
5. Refer to Figure D-4 and use needle-nose pliers to move the jumper to the Digital I/O position.
6. Replace the outer cover, and secure the carrying straps.
7. Make the necessary wire connections to the digital connector.

Digital I/O Operation

The digital port can be configured (see Figure D-4) to provide a digital input/output to be used with custom digital interface
circuits or relay circuits. Some examples are shown Figure D-5. See Figure D-1 for the pin assignments of the mating plug
and Table 1-5 for the electrical characteristics of the port. See DIG:DATA[:VAL] in “Chapter 3 - Language Dictionary" of
the Programming Guide for information on programming the port. The digital port pins are as follows:

OUT 0 (pin 1) This port can only be used as an open-collector output. It is assigned a bit weight of 1.

OUT 1 (pin 2) This port can only be used as an open-collector output. It is assigned a bit weight of 2.

IN/OUT 2 (pin 3) This port can be programmed to be either a high impedance input or an open-collector output.

Common (pin 4) This pin is the common connection for the Digital I/O ports.

Figure D-5. Digital l/O Port Applications

126 Digital Port Functions

Relay Link Operation

Relay link operation cannot be used with units that output more than 50 amps. (Some 667xA series
units; all 668xA and 669xA series units.)

The digital port can be configured to provide relay control outputs for the Agilent 59510A or 59511A Relay Accessory.
Refer to Figure D-1 for the pin assignments of the mating plug.

RLY SEND Provides the serial data to control the relays in the Relay Accessory.
(pin 1)
(pin 2) (Not used)
RLY RTN Receives the data readback that indicates the status of the relays in the Relay Accessory.
(pin 3)

Common Common connection for the RLY SEND and RLY RTN lines.
(pin 4)

Figure D-6 shows how to connect your power supply to an Agilent 59510A or 59511A Relay Accessory when the digital
port is configured for relay link operation. An error will be generated if you attempt to program the relay box without first
configuring the digital port for relay link operation. For more information about programming the relay, refer to
OUTP:REL[:STAT] in Chapter 3 of the Programming Guide. For more information about the Relay Accessory, refer to its
manual (see Table 1-6).

Figure D-6. Relay Link Connections

Digital Port Functions 127

 E
Current Loop Compensation (Series 668xA Only)

Introduction
This section describes how you may use current loop compensation to optimize for inductive loads or for fast CV/CC mode
crossover. A 7-position compensation switch for this purpose is located under the cover on the rear of the power supply.

Function of Loop Compensation

Figure E-1 shows the switch settings for specific combinations of load inductance and resistance. Two sets of curves show
the small-signal response for each model. The dashed curves represent programming performance of no more than 10%
current overshoot. The solid curves represent operating conditions with 25% overshoot. The curve obtained with all
switches open gives the fastest CC mode crossover response time. However, as shown by these curves, the loop will not
tolerate larger inductances unless the load resistance is increased. The curve described when all switch positions are closed
shows the as-shipped performance curve. This position provides 10% overshoot and fast CV/CC crossover performance for
load inductances that are specific for each model. (For Models 6680A and 6681A, this curve ranges from 100 µohms at
15 µhenries to about 100 milliohms at 40 millihenries.). You can select a different compensation curve by opening a
specific switch or combination of switches.

Table E-1 shows some specific L ÷ R ratios and the switch positions required for these ratios. Table E-1 is valid only for
Models 6680A and 6681A - you must use the curves for the remaining models. The corresponding 10% overshoot
curves are shown in Figure E-1. As operation moves along the curves from left to right, the switch positions must be
changed as shown along the X-axis.

Table E-1.
Settings For CC Loop Compensation Switch (Models 6680A and 6681A Only)
1
Load Characteristic (L/R) Switch Setting
7 6 5 4 3 2 1
1 µH/3 mΩ 0 0 0 0 0 0 0
2
15 µH/100 µΩ 1 1 1 1 1 1 1
30 µH/100 µΩ 0 0 0 0 0 0 1
100 µH/100 µΩ 1 1 1 1 1 1 0
150 µH/100 µΩ 0 0 0 0 0 1 0
600 µH/100 µΩ 1 1 1 1 1 0 0
1.2 mH/100 µΩ 0 0 0 0 1 0 0
4 mH/100 µΩ 1 1 1 1 0 0 0
10 mH/100 µΩ 0 0 0 1 0 0 0
40 mH/100µΩ 1 1 1 0 0 0 0
100 mH/100 µΩ 0 0 1 0 0 0 0
380 mH/100 µΩ 1 1 0 0 0 0 0
650 mH/100 µΩ 0 1 0 0 0 0 0
7 H/100 µΩ 1 0 0 0 0 0 0

1 2
"1" = switch closed; "0" = switch open. Factory setting.

Current Loop Compensation (Series 668xA Only) 129

For example, examine Figure E-l for the Model 6680A/6681A. The chart shows that a load comprised of about
1 millihenry inductance and 100 micro ohms resistance (see point ) requires switch setting 9 (only switch 3 closed) to
obtain 10% overshoot. If the load resistance is increased to 1 milliohm, then the operating position will be to the left of the
existing compensation curve (see point ). This will result in a stable condition with less overshoot, but greater CV/CC
crossover time than if the curve defined by switch setting 8 were used. If the load resistance remains at 1 milliohm but the
load inductance increases to 10 millihenries, then the operating position will be far to the right of the compensation curve
(see point ). This results in a less stable condition with more overshoot. To obtain better operation at point , use the
compensation curve defined by switch setting 13 (Model 6680A) or 12 (Model 6681A).

Most operating conditions will not fall directly on a curve and you will have to interpolate between curves. Generally,
moving to the left of a given curve increases stability. However, at large values of inductance the curves become almost
vertical because the load resistance has no effect on dampening the system. For Models 6680A and 6681A, the most stable
points are on the solid curves shown in Figure E-l. Points to the right or left of a curve will have more overshoot. Note the
two dashed vertical lines at switch setting 25 for Models 6682A, 6683A, and 6684A. Operation between these lines will
result in somewhat increased stability.

Note The best procedure is to test your settings under real operating conditions. For help in tailoring a specific
CC compensation, contact your Agilent Sales and Support Offices.

Figure E-1. CC Loop Compensation Curves for Models 6680A and 6681A

130 Current Loop Compensation (Series 668xA Only)

Figure E-1. CC Loop Compensation Curves For Models 6682A and 6683A

Current Loop Compensation (Series 668xA Only) 131

 Figure E-1. CC Loop Compensation Curves For Model 6684A

Setting the Loop Compensation Switch

SHOCK/ENERGY HAZARD. This procedure involves removing the outside cover and should only
be done by qualified electronics service personnel.

1. Turn off the power switch and disconnect the power cord from the power source. If this is not possible, remove the three
line fuses from the rear panel (see Figure 2-4).
2. Remove the four screws that secure the two carrying straps and outside cover.
3. Spread the bottom rear of the cover and pull it back to disengage it from the front panel.
4. Remove the cover by sliding it back towards the rear of the supply.
5. Locate the compensation switch (see Figure E-2).
6. Move the switches to the desired position.
7. Replace the outside cover.

Figure E-2. CC Loop Compensation Switch

132 Current Loop Compensation (Series 668xA Only)

 F
Using Agilent 668xA/669xA Series Power Supplies in
Autoparallel

Introduction
This information is supplementary to the information in chapter 4.

A maximum of three Agilent 668xA/669xA series power supplies having the same model number, may be configured for
autoparallel operation. The Agilent 668xA/669xA power supplies were designed with an external programming offset so
that the master unit will output current before the slave units do. Therefore, slave supplies will always sink current when low
output current values are desired.

Autoparallel Procedure

1. Connect the Agilent 668xA/669xA power supplies with the Im terminal from the master connected to the +Ip terminal of
each slave. Connect the êP terminal of the master to the -Ip terminal of each slave (see Figure 4-5e on page 81).

2. Each load lead should be of the same wire gauge and length.

3. Turn on all power supplies.

4. Program each slave supply for zero (0) output current either by pressing [CURRENT ] [0] [ENTER] from the front panel
keypad or sending the command "CURR:LEV 0" via the GPIB (see notes 2 and 3 on the follwing page).

5. Program each slave's output voltage at least 2 volts higher than the output voltage that the master supply will be
programmed to.

6. Program the master supply's output current for a value slightly greater than one-half of the total desired output current if
there is one slave supply, or one-third of the total desired output current if there are two slave supplies.

7. Enable all power supplies by pressing the [Output On/Off ] key.

8. Increase the master supply's output voltage. At low output currents, the master unit will be supplying all of the load
current and the slave supplies will be sinking current, which is normal. At maximum output current each supply will be
delivering an equal amount of output current. When operating at less than maximum current, it is normal to have unequal
current sharing between the master and slave supplies. Current sharing among the supplies only becomes equal at
maximum output current (see Figure F-1 ).

9. For remote sensing, connect only the master supply's +S and -S lines. Slave supplies should be connected for local
sensing at the rear of their respective output terminals.

Note 1 The current division between the master and slaves can be determined as follows:
Iout=Im [ 1 +Ns ( 1 +0.127V/5V)] - Ns Ifs (0.127V/5V)

The amount of current the master unit must output before the slave units will output current can be determined as follows:
Ns * Ifs (0.127V/5V)
where Im = master current
Ns = number of slaves
Ifs = full scale current

Using Agilent 668xA/669xA Series Power Supplies in Autoparallel 133

Example: 1 master unit, 2 slave units, Agilent Models 6680A (5V, 875A)
Iout = Im ( 3.0508 ) - 44.4A
The master current limit must be set above 44.4A /3.0508 = 14.55A to obtain any output current. For a no-load condition:
Master current =14.55A
Each slave current = -14.55A /2 = -7.28A
Iout = 0A

Note 2 All Agilent 668xAand 669xA power supplies have an output current programmed at power-on. The
default current value programmed at power-on can be found in Table 3-1 of the Programming Guide (p/n
5964-8269). See *RST and *SAV in the Programming Guide to change the power-on current value.

Note 3 A current programmed via the rear panel +Ip or -Ip inputs will be summed with the current programmed
via the front panel keypad or over the GPIB. When programming slave supplies via the rear panel +Ip or
-Ip inputs, all slave current programming values must be zero (0 ).

Figure F-1 Master/Slave Current Division

134 Using Agilent 668xA Series Power Supplies in Autoparallel

 G
Output Bus Bar Options

Option 601 Installation

WARNING ENERGY HAZARD. The Series 668xA/669xA power supplies can provide more than 240 VA at
more than 2 V. If the output connections touch, severe arcing may occur resulting in burns,
ignition or welding of parts. Do not attempt to make connections while the output is live.

The Option 602 kit allows bench operation of the Series 668xA/669xA power supplies. It provides an insulating cover and
means for vertical conections to the output bus bars to prevent accidental contact between the two bus bars and external
objects at the rear of the power supply.

Each option contains an output cover with a cutout to permit the load leads to be run down from above or up from below the
power supply. The option also includes four screws for fastening the cover to the rear panel, a bus bar spacer with mounting
hardware, and a bus bar hardware kit for connectiong the load leads to the output bus bars.

Install the bus bar spacers on either output bus bar to permit clearence between the − and + output leads (see Option 602
instructions for mounting details). Using the bus bar hardware kit, connect the output leads either from above or below the
bus bars. Then install the output cover and secure it with the four machine screws provided.)

(A) Output Cover, 5040-1692 (B) Bus Bar Hardware Kit, 5080-2313
(1) Screw, machine M4x0.7, 0515-1085 (4) (1) Bolt, 3/8 x 16 x 1.25 lg (3)
(C) Bus Bar Spacer, 5040-1699 (2) Bolt, 3/8 x 16 x 1.75 lg (3)
(1) Screw, machine M4x0.7, 0515-0981 (4) (3) Lockwasher, 3/8 (6)
(2) Lockwasher, 2190-0484 (4) (4) Flatwasher, 3/8 (6)
(3) Flatwasher, 3050-1053 (4) (5) Nut, 3/8 x 16 (6)
(D) DC Output Leads

Ouptut Bus Bar Options 135

Option 602 Installation

WARNING ENERGY HAZARD. The Series 668xA/669xA power supplies can provide more than 240 VA at
more than 2 V. If the output connections touch, severe arcing may occur resulting in burns,
ignition or welding of parts. Do not attempt to make connections while the output is live.

The Option 602 kit provides bus bar spacers to permit parallel operation between vertical power supplies, such as those in
an equipment rack.

Each kit has two bus bar spacers and the required hardware for attaching the spacers to the − and + bus bars. The spacers
have tapped holes for receiving the screws that are inserted through clearence holes in the bus bars. Either spacer may be
used with either bus bar. Secure the spacers on opposite sides of the bus bars as shown in the figure. Be sure to insert the
flatwashers and lockwashers.

When the spacers have been installed, connect the bus rails between the two power supplies. Use the original bus bar
hardware or the hardware provided with the Bus Bar Hardware Kit 5080-2313 (see option 601)

(A) Bus Bar Spacer, 5040-1699 (2) (B) Minus Bus Bar
(1) Screw, machine M4x0.7, 0515-0981 (4) (C) Plus Bus Bar
(2) Lockwasher, 2190-0484 (4) (D) Customer bus rails
(3) Flatwasher, 3050-1053 (4)

136 Output Bus Bar Options

Index
—A— 667xA, 69
ac disconnect switch, 47, 48 668xA and 669xA, 76
accessories, 13 CC loop compensation
air clearence, 44 668xA, 129
air flow, 44, 52 curves, 130
analog CC mode, 91, 129, 130
connector, 43 characteristics
analog port, 60 664xA, 17
characteristics. See Supplemental Characteristics 665xA, 22
connector configuration, 60 667xA, 27
signals, 60 668xA, 32
analog programming. See external voltage control 669xA, 37
annunciator, 86 output, 15
Addr, 86 checkout, 51
Cal, 86 output current, 54
CC, 53, 86 output voltage, 53
CV, 52, 53, 86 power-on, 52
Dis, 52, 54, 86 preliminary, 51
Err, 86 common commands. See Programming Guide
OCP, 54, 86 common P, 60, 68, 75, 82
Prot, 53, 54, 86, 124 Compatibility language. See Programming Guide
Rmt, 86 connections
Shift, 52, 86 664xA and 665xA in parallel, 65
SRG, 86 664xA and 665xA in series, 67, 74
Unr, 63, 71, 86, 92 664xA and 665xA with multiple loads, 65
autoparallel 667xA in parallel, 73
668xA and 669xA, 133 667xA with multiple loads, 72
AWG ratings, 59 668xA and 669xA in parallel, 80
668xA and 669xA in series, 81
668xA and 669xA with multiple loads, 79
—B— controller, 83
BASIC, 102 connector
battery charging analog port, 60
664xA and 665xA, 62 digital port, 60, 123
667xA, 70 controller connections, 83
668xA and 669xA, 77 linked, 83
stand alone, 83
current control, 14, 54, 87
—C— current programming, 90
cables, 13 CV mode, 91
calibration, 95
current, 98 —D—
current monitor, 99
default password, 96 damage, 43
disabling, 96 DFI/RI, 80, 81
enabling, 98 digital connector, 43, 60, 123
equipment required, 95 digital port
jumper, 98 applications, 126
over GPIB, 100 characteristics, 41
OVP, 98 configuration jumper, 125
program, 102 pin configuration, 126
SCPI commands, 100 dimensions, 44
test setup, 97 direct supply, 83, 93
voltage, 98 downprogramming, 15
capacitive load
664xA and 665xA, 61

Index 137
 —E— —G—
energy hazard, 54, 76, 90, 95, 108, 132 general information, 11
error messages GPIB
calibration, 99 address, 55, 93
checksum, 58 address, primary, 83, 93
power-on, 57 address, secondary, 83, 93
run-time, 58 GPIB system supplies, 13
selftest, 57 ground
system. See Programming Guide earth, 12, 46, 47, 49
external voltage control, 14 signal, 123
664xA and 665xA, 67 Guide, Operating, 11
667xA, 75 Guide, Programming, 11
668xA and 669xA, 82 Guide, Service, 13
capacitive coupling, 67
—H—
—F—
hardware, 41
fan, 44, 52, 55 history, 4
features, 14
fire hazard, 59
FLT output, 123
—I—
font panel keys inductive load
Cal Disable, 96 664xA and 665xA, 62
Cal Enable, 96 667xA, 69
Pass, 96 668xA, 129
front panel 668xA and 669xA, 77
controls and indicators, 14 INH input, 123
front panel keys initial conditions, 88
↑Current, 87 input
↑Voltage, 53, 87 connections, 45
Address, 87, 93 power, 12
Back, 52, 88 input rail LED, 56
Cal Save, 96 667xA, 120
Clear Entry, 88 668xA and 669xA, 121
Current, 54, 87 inspection, 43
Current↓, 54 isolation. See output isolation
Enter, 52, 88
Error, 87
Local, 87
—J—
OCP, 54, 87, 91 jumper
Output On.Off, 87 calibration, 98
Output On/Off, 52 line select for 664xA and 665xA, 120
OV, 53, 87 line select for 668xA and 669xA, 122
Prot Clear, 55, 87, 90 local sense, 667xA, 70
Protect, 53, 55, 87, 90 local sense, 668xA and 669xA, 77
Recall, 55, 87
Save, 55, 87
Shift, 52, 87 —L—
Voltage, 53, 87 line fuse, 55
fuse line voltage conversion
664xA and 665xA, 45, 56 664xA and 665xA, 119
667xA, 45, 56 667xA, 120
668xA, 47, 57 668xA and 669xA, 121
669xA, 48, 57 linked connections, 83
kit, 13 linked supply, 83, 93
power, 41 load L/R ratio
fuse indicator window, 669xA, 57 668xA, 129
local sensing. See local voltage sensing
local voltage sensing, 62, 70, 77

138 Index
location, 44 power cord, 12, 43
664xA and 665xA, 45
667xA, 45
—M— 668xA, 47
manuals, 11, 41 669xA, 48
message installation, 45
CAL DENIED, 98 power receptacle, 12
error. See error messages power-on selftest, 52
OC, 91 preliminary checkout, 51
OUT OF RANGE, 89, 90 print date, 4
PWR ON INIT, 52 programming
RCL 0 PWR-ON, 92 accuracy. See Performance specifications
RST POWER-ON, 92 errors. See Programming Guide
meter mode, 52 parameters. See Programming Guide
multiple load connections resolution. See characteristics
664xA and 665xA, 65 Programming Guide, 11
667xA, 72 Protect key. See front panel keys
668xA and 668xA, 79
—R—
—N— rack mount kit, 12, 44
nonvolatile memory, 92 rack mounting, 44
recalling states, 55, 92
relay link
—O— connections, 127
OCP key. See front panel keys pin configuration, 127
operating features, 14 remote programming, 14
Operating Guide, 11 remote voltage sensing
operating modes, 15 and 664xA and 665xA load regulation, 63
options, 12 and 664xA and 665xA output noise, 63
output characteristic, 15, 89 and 664xA and 665xA output rating, 63
664xA, 19 and 664xA and 665xA output stability, 64
6665xA, 24 and 664xA and 665xA OVP operation, 63
667xA, 29 and 667xA load regulation, 71
668xA, 34 and 667xA output noise, 71
669xA, 39 and 667xA output rating, 71
output isolation and 667xA output stability, 71
664xA and 665xA, 61 and 667xA OVP operation, 71
667xA, 68 and 668xA and 669xA load regulation, 77
668xA and 669xA, 76 and 668xA and 669xA output noise, 78
overcurrent protection, 91 and 668xA and 669xA output rating, 78
clearing, 91 and 668xA and 669xA output stability, 78
operation, 91 and 668xA and 669xA OVP operation, 78
setting, 91 repacking, 43
overvoltage protection, 89 RI, remote inhibit. See INH input
clearing, 90
operation, 90 —S—
setting, 89
safety class, 12
safety compliance
—P— 664xA, 6
pack return system, 43 safety cover, 41, 47, 49
parallel connections safety summary, 3
664xA and 665xA, 65 safety warning, 12, 44, 47, 48, 54, 56, 59, 61, 67, 69, 74, 76,
667xA, 73 81, 90, 95, 108, 119, 120, 121, 126, 132
668xA and 669xA, 80 saving states, 92
parallel procedure serial cable, 43
668xA and 669xA, 133 serial number, 12
parts series connections
operator replaceable, 41 664xA and 665xA, 67, 74
668xA and 669xA, 81

Index 139
Service guide, 13 667xA, 71
shock hazard, 119, 120, 121, 126, 132
slide mount kit, 13
specifications, 15
—V—
664xA, 16 verification, 105
665xA, 21 current monitor resistor, 105
667xA, 26 current programming and readback, 108
668xA, 31 equipment required, 105
669xA, 36 test parameters for 664xA, 109
support rails, 44 test parameters for 665xA, 111
switch test parameters for 667xA, 113
CC loop compensation (668xA), 129, 132 test parameters for 668xA, 115
line select for 664xA and 665xA, 119 test parameters for 669xA, 117
line select for 667xA, 120 test setup, 106
local sense (664xA/665xA), 51 voltage programming and readback, 107
local sense, 664xA and 665xA, 62 verification tests, 51
voltage control, 14, 53, 87
—T— voltage programming, 89
voltage sensing. See local voltage sensing or remote voltage
temperature performance, 44 sensing
turn-on
checkout, 51
conditions, 92
—W—
warning. See safety warning
—U— warranty, 2
wire
unregulated operation, 92 current ratings, 59
664xA and 665xA, 63 wiring considerations, 59

140 Index
Agilent Sales and Support Offices

For more information about Agilent Technologies test and measurement products, applications, services, and for a current
sales office listing, visit our web site: http://www.agilent.com/find/tmdir

You can also contact one of the following centers and ask for a test and measurement sales representative.

United States: Latin America:

Agilent Technologies Agilent Technologies
Test and Measurement Call Center Latin American Region Headquarters
P.O. Box 4026 5200 Blue Lagoon Drive, Suite #950
Englewood, CO 80155-4026 Miami, Florida 33126
(tel) 1 800 452 4844 U.S.A.
(tel) (305) 267 4245
(fax) (305) 267 4286

Canada: Australia/New Zealand:

Agilent Technologies Canada Inc. Agilent Technologies Australia Pty Ltd
5150 Spectrum Way 347 Burwood Highway
Mississauga, Ontario Forest Hill, Victoria 3131
L4W 5G1 (tel) 1-800 629 485 (Australia)
(tel) 1 877 894 4414 (fax) (61 3) 9272 0749
(tel) 0 800 738 378 (New Zealand)
(fax) (64 4) 802 6881

Europe: Asia Pacific:

Agilent Technologies Agilent Technologies
Test & Measurement European Marketing Organisation 24/F, Cityplaza One, 1111 King's Road,
P.O. Box 999 Taikoo Shing, Hong Kong
1180 AZ Amstelveen tel: (852)-3197-7777
The Netherlands fax: (852)-2506-9284
(tel) (31 20) 547 9999

Japan:
Agilent Technologies Japan Ltd.
Measurement Assistance Center
9-1, Takakura-Cho, Hachioji-Shi,
Tokyo 192-8510, Japan
(tel) (81) 426 56 7832
(fax) (81) 426 56 7840

Technical data is subject to change.

Manual Updates
The following updates have been made to this manual since the original print date.

3/01/02

All references to the front panel Check Fuses LED on series 668xA have been removed.

5/01/02

Additional information has been added about Power Cord options.

The CC rms noise specification for series 668xA and 669xA is categorized as a supplemental characteristics.
Additional information has been added under External Voltage Control for series 664xA and 665xA.

11/06/02

Information has been added to the Safety summary page and Section 2 to comply with EN61010 regulations.