INTEGRATED CIRCUITS

MC1408-8
8-bit multiplying D/A converter

Product data 2001 Aug 03

Supersedes data of 1994 Aug 31
File under Integrated Circuits, IC11 Handbook






Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

DESCRIPTION PIN CONFIGURATIONS

The MC1408-8 is an 8-bit monolithic digital-to-analog converter
which provides high-speed performance with low cost. It is designed N Package
for use where the output current is a linear product of an 8-bit digital 1 16 COMPEN
NC
word and an analog reference voltage.
GND 2 15 VREF(–)

VEE 3 14 V
REF(+)
FEATURES IO 4 13 V
CC
• Fast settling time: 70 ns (typ) MSB A1 5 12 A
8 LSB

• Relative accuracy ±0.19% (max error) A2 6 11 A7

• Non-inverting digital inputs are TTL and CMOS compatible A3 7 10 A6

• High-speed multiplying rate 4.0 mA/µs (input slew)

A4 8 9 A5

• Output voltage swing +0.5 V to –5.0 V D Package1

• Standard supply voltages +5.0 V and –5.0 V to –15 V V+ 1 16 A8 LSB

VREF(+) 2 15 A7

VREF(–) 3 14 A6
APPLICATIONS
• Tracking A-to-D converters COMPEN 4 13 A5

• 2 1/2-digit panel meters and DVMs NC 5 12 A4

6 11 A3
• Waveform synthesis
GND
V– 7 10 A2
• Sample-and-Hold IO 8 9 A1 MSB

• Peak detector TOP VIEW

• Programmable gain and attenuation NOTE:

1. SO and non-standard pinouts. SL00048

• CRT character generation
Figure 1. Pin Configurations
• Audio digitizing and decoding
• Programmable power supplies
• Analog-digital multiplication
• Digital-digital multiplication
• Analog-digital division
• Digital addition and subtraction
• Speech compression and expansion
• Stepping motor drive modems
• Servo motor and pen drivers

ORDERING INFORMATION
DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #
16-Pin Plastic Dual In-Line Package (DIP) 0 °C to +70 °C MC1408-8N SOT38-4
16-Pin Small Outline (SO) Package 0 °C to +70 °C MC1408-8D SOT109-1

2001 Aug 03 2 853-0935 26835

Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

BLOCK DIAGRAM
MSB LSB
A1 A2 A3 A4 A5 A6 A7 A8

5 6 7 8 9 10 11 12

IO

CURRENT SWITCHES 4

BIAS 2
R-2R LADDER CURRENT
GND

VREF
(+)
14 13
VCC
REFERENCE
15 CURRENT
(–) AMPLIFIER
VREF
16
COMPEN

VEE 3

NPN CURRENT SOURCE PAIR SL00049

Figure 2. Block Diagram

CIRCUIT DESCRIPTION feedback. The termination amplifier holds the parasitic capacitance
The MC1408-8 consists of a reference current amplifier, an R-2R of the ladder at a constant voltage during switching, and provides a
ladder, and 8 high-speed current switches. For many applications, low impedance termination of equal voltage for all legs of the ladder.
only a reference resistor and reference voltage need be added. The R-2R ladder divides the reference amplifier current into
The switches are non-inverting in operation; therefore, a high state binary-related components, which are fed to the remainder current
on the input turns on the specified output current component. which is equal to the least significant bit. This current is shunted to
ground, and the maximum output current is 255/256 of the reference
The switch uses current steering for high speed, and a termination amplifier current, or 1.992 mA for a 2.0 mA reference amplifier
amplifier consisting of an active load gain stage with unity gain current if the NPN current source pair is perfectly matched.

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNIT
VCC Positive power supply voltage +5.5 V
VEE Negative power supply voltage –16.5 V
V5 – V12 Digital input voltage 0 to VCC V
VO Applied output voltage –5.2 to +18 V
I14 Reference current 5.0 mA
V14, V15 Reference amplifier inputs VEE to VCC
Maximum power dissipation, Tamb = 25 °C (still-air)1
PD N package 1450 mW
D package 1080 mW
Tamb Operating temperature range 0 to +75 °C
Tstg Storage temperature range –65 to +150 °C
Tsld Lead soldering temperature (10 sec) +230 °C
NOTES:
1. Derate above 25°C, at the following rates:
N package at 11.6 mW/°C;
D package at 8.6 mW/°C

2001 Aug 03 3
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

DC ELECTRICAL CHARACTERISTICS
Pin 3 must be 3 V more negative than the potential to which R15 is returned. VCC = +5.0 VDC, VEE = –15 VDC, VREF/R14 = 2.0 mA unless
otherwise specified. Tamb = 0 °C to 75 °C, unless otherwise noted.
MC1408-8
SYMBOL PARAMETER TEST CONDITIONS UNIT
Min Typ Max
Er Relative accuracy Error relative to full-scale IO, Figure 6 ±0.19 %
To within 1/2 LSB, includes tPLH;
tS Settling time1 70 ns
Tamb = +25 °C, Figure 7
Propagation delay time
tPLH Low-to-High Tamb = +25 °C, Figure 7 35 100 ns
tPHL High-to-Low
TCIO Output full-scale current drift –20 ppm/°C
Digital input logic level (MSB)
VIH High Figure 8 2.0 VDC
VIL Low 0.8
Digital input current (MSB) Figure 8
IIH High VIH = 5.0 V 0 0.04 mA
IIL Low VIL = 0.8 V –0.4 –0.8
I15 Reference input bias current Pin 15, Figure 8 –1.0 –5.0 µA
Figure 8
IOR Output current range VEE = –5.0 V 0 2.0 2.1 mA
VEE = –7.0 V to –15 V 0 2.0 4.2
IO Output current Figure 8
VREF = 2.000 V, 1.9 1.99 2.1 mA
R14 = 1000 Ω
IO(min) Off-state All bits low 0 4.0 µA
Er ≤ 0.19% at
TA = +25°C, Figure 8
VEE = –5V –0.6 –0.55,
VO Output
Out compliance
ut voltage com liance VDC
+10 +0.5
VEE below –10V –5.5, –5.0,
+10 +0.5
SRIREF Reference current slew rate Figure 9 8.0 mA/µs
Output current power supply
PSRR(–) IREF = 1 mA 0.5 2.7 µA/V
sensitivity
Power supply current
ICC Positive All bits low, Figure 8 +2.5 +22 mA
IEE Negative –6.5 –13
Power supply voltage range
VCCR Positive Tamb = +25 °C, Figure 8 +4.5 +5.0 +5.5 VDC
VEER Negative –4.5 –15 –16.5
All bits low, Figure 8
PD Power dissipation VEE = –5.0 VDC 34 170 mW
VEE = –15.0 VDC 110 305
NOTES:
1. All bits switched.

2001 Aug 03 4
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

TYPICAL PERFORMANCE CHARACTERISTICS A negative reference voltage may be used if R14 is grounded and
the reference voltage is applied to R15, as shown in Figure 5. A high
D-to-A TRANSFER CHARACTERISTICS
input impedance is the main advantage of this method. The negative
IO OUTPUT CURRENT (mA)

reference voltage must be at least 3.0 V above the VEE supply.

0
Bipolar input signals may be handled by connecting R14 to a positive
reference voltage equal to the peak positive input level at Pin 15.
1.0
Capacitive bypass to ground is recommended when a DC reference
voltage is used. The 5.0 V logic supply is not recommended as a
2.0 reference voltage, but if a well regulated 5.0 V supply which drives
logic is to be used as the reference, R14 should be formed of two
(00000000) INPUT DIGITAL WORD (11111111) series resistors and the junction of the two resistors bypassed with
SL00050
0.1 µF to ground. For reference voltages greater than 5.0 V, a clamp
Figure 3. Typical Performance Characteristics diode is recommended between Pin 14 and ground.
If Pin 14 is driven by a high impedance such as a transistor current
source, none of the above compensation methods apply and the
FUNCTIONAL DESCRIPTION amplifier must be heavily compensated, decreasing the overall
bandwidth.
Reference Amplifier Drive and Compensation
The reference amplifier input current must always flow into Pin 14.
regardless of the setup method or reference supply voltage polarity.
VCC
Connections for a positive reference voltage are shown in Figure 4.
The reference voltage source supplies the full reference current. For R14 = R15
13
bipolar reference signals, as in the multiplying mode, R15 can be 5
A1 R14
tied to a negative voltage corresponding to the minimum input level. 6 14
R15 may be eliminated and Pin 15 grounded, with only a small A2
7 15 (–)VREF
sacrifice in accuracy and temperature drift. A3
8 1 R15
A4
9 MC1408 2
A5 RL
10 4
VCC A6
11 IO
16
A7
13 R14 = R15 12
5 A8 SEE TEXT FOR VALUES OF C.
A1 R14 C
3
6 14 (+)VREF
A2
7 15
A3
R15 VEE
8 1 SL00052
A4
9 MC1408 2
A5 RL Figure 5. Negative VREF
10 4
A6
11 IO
16
A7
A8
12
SEE TEXT FOR VALUES OF C.
Output Voltage Range
C The voltage at Pin 4 must always be at least 4.5 V more positive
3
than the voltage of the negative supply (Pin 3) when the reference
current is 2 mA or less, and at least 8 V more positive than the
VEE negative supply when the reference current is between 2 mA and
SL00051
4 mA. This is necessary to avoid saturation of the output transistors,
Figure 4. Positive VREF which would cause serious degradation of accuracy.
Philips Semiconductors MC1408-8 does not need a range control
The compensation capacitor value must be increased with because the design extends the compliance range down to 4.5 V (or
increasing values of R14 to maintain proper phase margin. For R14 8 V — see above) above the negative supply voltage without
values of 1.0, 2.5, and 5.0 kΩ, minimum capacitor values are 15, 37, significant degradation of accuracy. Philips Semiconductors
and 75 pF. The capacitor may be tied to either VEE or ground, but MC1408-8 can be used in sockets designed for other
using VEE increases negative supply rejection. (Fluctuations in the manufacturers’ MC1408 without circuit modification.
negative supply have more effect on accuracy than do any changes
in the positive supply.)

2001 Aug 03 5
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

Output Current Range Monotonicity

Any time the full-scale current exceeds 2 mA, the negative supply A monotonic converter is one which always provides an analog
must be at least 8 V more negative than the output voltage. This is output greater than or equal to the preceding value for a
due to the increased internal voltage drops between the negative corresponding increment in the digital input code. The MC1408-8 is
supply and the outputs with higher reference currents. monotonic for all values of reference current above 0.5 mA. The
recommended range for operation is a DC reference current
Accuracy between 0.5 mA and 4.0 mA.
Absolute accuracy is the measure of each output current level with
respect to its intended value, and is dependent upon relative Settling Time
accuracy, full-scale accuracy and full-scale current drift. Relative The worst case switching condition occurs when all bits are
accuracy is the measure of each output current level as a fraction of switched on, which corresponds to a low-to-high transition for all
the full-scale current after zero-scale current has been nulled out. input bits. This time is typically 70 ns for settling to within 1/2LSB for
The relative accuracy of the MC1408-8 is essentially constant over 8-bit accuracy. This time applies when RL < 500 Ω and CO < 25 pF.
the operating temperature range because of the excellent The slowest single switch is the least significant bit, which typically
temperature tracking of the monolithic resistor ladder. The reference turns on and settles in 65 ns. In applications where the D-to-A
current may drift with temperature, causing a change in the absolute converter functions in a positive going ramp mode, the worst-case
accuracy of output current; however, the MC1408-8 has a very low condition does not occur and settling times less than 70 ns may be
full-scale current drift over the operating temperature range. realized.
The MC1408-8 series is guaranteed accurate to within ±1/2 LSB at Extra care must be taken in board layout since this usually is the
+25 °C at a full-scale output current of 1.99 mA. The relative dominant factor in satisfactory test results when measuring settling
accuracy test circuit is shown in Figure 6. The 12-bit converter is time. Short leads, 100 µF supply bypassing for low frequencies,
calibrated to a full-scale output current of 1.99219 mA; then the minimum scope lead length, good ground planes, and avoidance of
MC1408-8’s full-scale current is trimmed to the same value with R14 ground loops are all mandatory.
so that a zero value appears at the error amplifier output. The
counter is activated and the error band may be displayed on the
oscilloscope, detected by comparators, or stored in a peak detector.
Two 8-bit D-to-A converters may not be used to construct a 16-bit
accurate D-to-A converter. 16-bit accuracy implies a total of
±1/2 part in 65,536, or ±0.00076%, which is much more accurate
than the ±0.19% specification of the MC1408-8.

MSB

A1
A2
12-BIT
A3 D-TO-A
A4 CONVERTER 0 TO +10V OUTPUT
A5 (±0.02%
A6 ERROR MAX)
A7 5k
A8 A9 A10 A11 A12

LSB 50k

VREF = 2V 0.1µF

–
100 +
950 ERROR (1V = 1%)
VCC
R14 NE530

MSB 14 13
5
6
7
8 4
8-BIT MC1408
COUNTER 9
10
11
12
LSB
15 16 3 2 1

1k C

VEE
SL00053

Figure 6. Relative Accuracy

2001 Aug 03 6
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

VCC

0.1µF

13 2.4V
+2VDC 1.4V
eIN
5 0.4V
1.0k R14
6 14 tPHL = tPLH = 10ns
USE RL to GND
7 15 1.0V
0.1µF FOR TURN OFF
8 1 1.0k
RL SETTLING TIME MEASUREMENT
9 MC1408 2 FOR SETTLING TIME
MEASUREMENT RL = 500Ω
10 4
eIN (ALL BITS 0
11 16 eO SWITCHED LOW
12 TO HIGH) tS = 70ns TYPICAL
51 TO ±1/2LSB
15pF
3
0.1µF CO ≤ 25pF TRANSIENT
0
RESPONSE RL = 50Ω
–100 PIN 4 TO GND
mV
VEE tPLH tPHL

SL00054

Figure 7. Transient Response and Settling Time

VCC TYPICAL VALUES R14 = R15 = 1k

ICC VREF = +2.0V
C = 15pF
13 VI AND II APPLY TO INPUTS A1 THROUGH A8
I14 R14
5 14
A1 VREF(+)
A2 6 I15 THE RESISTOR TIED TO PIN 15 IS TO TEMPERATURE COMPENSATE THE
7 15 BIAS CURRENT AND MAY NOT BE NECESSARY FOR ALL APPLICATIONS
A3
8 1 R15
A4
DIGITAL 9 2 A1 A2 A3 A4 A5 A6 A7 A8
A5 MC1408
INPUTS I + K ) ) ) ) ) ) )
10 O 2 4 8 16 32 64 128 256
A6 4 VO
11
A7 OUTPUT V REF
12 16 IO where K +
A8 R 14
(+) RL
II 3
VI and AN = “1” IF AN IS AT HIGH LEVEL
AN = “0” IF AN IS AT LOW LEVEL
IEE
VEE (SEE TEXT FOR VALUES OF C.)
SL00055

Figure 8. Notation Definitions

VCC

13

5
6 14 1k VREF
7 15
8 1 1k
9 MC1408 2
10
11 4
12 16 10% 0
dI I dV 90%
SCOPE + 2.0mA
3 15pF dt R L dt
RL = 50
SLEWING TIME
VEE SL00056

Figure 9. Reference Current Slew Rate Measurement

2001 Aug 03 7
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

DIP16: plastic dual in-line package; 16 leads (300 mil) SOT38-4

2001 Aug 03 8
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

SO16: plastic small outline package; 16 leads; body width 3.9 mm SOT109-1

2001 Aug 03 9
Philips Semiconductors Product data

8-bit multiplying D/A converter MC1408-8

Data sheet status

Product Definitions
Data sheet status [1]
status [2]

Objective data Development This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.

Preliminary data Qualification This data sheet contains data from the preliminary specification. Supplementary data will be
published at a later date. Philips Semiconductors reserves the right to change the specification
without notice, in order to improve the design and supply the best possible product.
Product data Production This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply.
Changes will be communicated according to the Customer Product/Process Change Notification
(CPCN) procedure SNW-SQ-650A.
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.

Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.

Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.

Contact information  Koninklijke Philips Electronics N.V. 2002

For additional information please visit All rights reserved. Printed in U.S.A.
http://www.semiconductors.philips.com. Fax: +31 40 27 24825
Date of release: 01-02
For sales offices addresses send e-mail to:
sales.addresses@www.semiconductors.philips.com. Document order number: 9397 750 09381






2001 Aug 03 10