Precision Micropower, Low Noise CMOS,

Rail-to-Rail Input/Output Operational Amplifiers

AD8603/AD8607/AD8609
FEATURES PIN CONFIGURATIONS
Low offset voltage: 50 μV maximum OUT 1 5 V+
Low input bias current: 1 pA maximum AD8603
V– 2 TOP VIEW
Single-supply operation: 1.8 V to 5 V (Not to Scale)

04356-001
Low noise: 22 nV/√Hz +IN 3 4 –IN

Micropower: 50 μA maximum
Figure 1. 5-Lead TSOT (UJ Suffix)
Low distortion
No phase reversal
Unity gain stable OUT A 1 8 V+
–IN A 2 AD8607 7 OUT B
TOP VIEW
+IN A 3 6 –IN B
(Not to Scale)

04356-002
APPLICATIONS V– 4 5 +IN B

Battery-powered instrumentation Figure 2. 8-Lead MSOP (RM Suffix)

Multipole filters
Sensors
OUT A 1 8 V+
Low power ASIC input or output amplifiers –IN A 2 AD8607 7 OUT B
+IN A 3 TOP VIEW 6 –IN B

04356-003
V– 4 (Not to Scale) 5 +IN B
GENERAL DESCRIPTION
The AD8603/AD8607/AD8609 are single/dual/quad micro- Figure 3. 8-Lead SOIC (R Suffix)

power rail-to-rail input and output amplifiers, respectively, that

feature very low offset voltage as well as low input voltage and OUT A 1 14 OUT D
current noise. –IN A 2 13 –IN D

These amplifiers use a patented trimming technique that achieves +IN A 3 AD8609 12 +IN D
TOP VIEW
V+ 4 11 V–
superior precision without laser trimming. The parts are fully (Not to Scale)
+IN B 5 10 +IN C
specified to operate from 1.8 V to 5.0 V single supply or from
–IN B 6 9 –IN C
±0.9 V to ±2.5 V dual supply. The combination of low offsets, low

04356-004
OUT B 7 8 OUT C
noise, very low input bias currents, and low power consumption
makes the AD8603/AD8607/AD8609 especially useful in portable Figure 4. 14-Lead TSSOP (RU Suffix)
and loop-powered instrumentation.
The ability to swing rail to rail at both the input and output OUT A 1 14 OUT D
enables designers to buffer CMOS ADCs, DACs, ASICs, and –IN A 2 13 –IN D
other wide output swing devices in low power, single-supply +IN A 3 AD8609 12 +IN D

systems. V+ 4 TOP VIEW 11 V–

(Not to Scale)
+IN B 5 10 +IN C
The AD8603 is available in a tiny 5-lead TSOT package. The
–IN B 6 9 –IN C
04356-005

AD8607 is available in 8-lead MSOP and 8-lead SOIC packages. OUT B 7 8 OUT C
The AD8609 is available in 14-lead TSSOP and 14-lead SOIC
packages. Figure 5. 14-Lead SOIC (R Suffix)

Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com
Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2003–2008 Analog Devices, Inc. All rights reserved.
AD8603/AD8607/AD8609

TABLE OF CONTENTS
Features .............................................................................................. 1 Applications..................................................................................... 12
Applications ....................................................................................... 1 No Phase Reversal ...................................................................... 12
General Description ......................................................................... 1 Input Overvoltage Protection ................................................... 12
Pin Configurations ........................................................................... 1 Driving Capacitive Loads .......................................................... 12
Revision History ............................................................................... 2 Proximity Sensors....................................................................... 13
Specifications..................................................................................... 3 Composite Amplifiers................................................................ 13
Electrical Characteristics ............................................................. 3 Battery-Powered Applications .................................................. 13
Absolute Maximum Ratings............................................................ 5 Photodiodes ................................................................................ 13
ESD Caution .................................................................................. 5 Outline Dimensions ....................................................................... 14
Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 16

REVISION HISTORY
6/08—Rev. B to Rev. C
Changes to Table 1 ............................................................................ 3
Changes to Table 2 ............................................................................ 4
Changes to Figure 15 ........................................................................ 7
Changes to Figure 33 ...................................................................... 10
Changes to Figure 45 and Figure 47 ............................................. 13
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 16

6/05—Rev. A to Rev. B
Updated Figure 49 .......................................................................... 15
Changes to Ordering Guide .......................................................... 17

10/03—Rev. 0 to Rev. A
Added AD8607 and AD8609 Parts .................................. Universal
Changes to Specifications ................................................................ 3
Changes to Figure 35 ...................................................................... 10
Added Figure 41.............................................................................. 11

8/03—Revision 0: Initial Version

Rev. C | Page 2 of 16
 AD8603/AD8607/AD8609

SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
VS = 5 V, VCM = VS/2, TA = 25°C, unless otherwise noted.

Table 1.
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage VOS VS = 3.3 V @ VCM = 0.5 V and 2.8 V 12 50 μV
−0.3 V < VCM < +5.2 V 40 300 μV
−40°C < TA < +125°C, −0.3 V < VCM < +5.2 V 700 μV
Offset Voltage Drift ∆VOS/∆T −40°C < TA < +125°C 1 4.5 μV/°C
Input Bias Current IB 0.2 1 pA
−40°C < TA < +85°C 50 pA
−40°C < TA < +125°C 500 pA
Input Offset Current IOS 0.1 0.5 pA
−40°C < TA < +85°C 50 pA
−40°C < TA < +125°C 250 pA
Input Voltage Range IVR −0.3 +5.2 V
Common-Mode Rejection Ratio CMRR 0 V < VCM < 5 V 85 100 dB
−40°C < TA < +125°C 80 dB
Large Signal Voltage Gain AVO RL = 10 kΩ, 0.5 V < VO < 4.5 V
AD8603 400 1000 V/mV
AD8607/AD8609 250 450 V/mV
Input Capacitance CDIFF 1.9 pF
CCM 2.5 pF
OUTPUT CHARACTERISTICS
Output Voltage High VOH IL = 1 mA 4.95 4.97 V
−40°C to +125°C 4.9 V
IL = 10 mA 4.65 4.97 V
−40°C to +125°C 4.50 V
Output Voltage Low VOL IL = 1 mA 16 30 mV
−40°C to +125°C 50 mV
IL = 10 mA 160 250 mV
−40°C to +125°C 330 mV
Short-Circuit Current ISC ±70 mA
Closed-Loop Output Impedance ZOUT f = 10 kHz, AV = 1 36 Ω
POWER SUPPLY
Power Supply Rejection Ratio PSRR 1.8 V < VS < 5 V 80 100 dB
Supply Current per Amplifier ISY VO = 0 V 40 50 μA
−40°C <TA < +125°C 60 μA
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kΩ 0.1 V/μs
Settling Time 0.1% tS G = ±1, 2 V step 23 μs
Gain Bandwidth Product GBP RL = 100 kΩ 400 kHz
RL = 10 kΩ 316 kHz
Phase Margin ØO RL = 10 kΩ, RL = 100 kΩ 70 Degrees
NOISE PERFORMANCE
Peak-to-Peak Noise en p-p 0.1 Hz to 10 Hz 2.3 3.5 μV
Voltage Noise Density en f = 1 kHz 25 nV/√Hz
f = 10 kHz 22 nV/√Hz
Current Noise Density in f = 1 kHz 0.05 pA/√Hz
Channel Separation CS f = 10 kHz −115 dB
f = 100 kHz −110 dB

Rev. C | Page 3 of 16
AD8603/AD8607/AD8609
VS = 1.8 V, VCM = VS/2, TA = 25°C, unless otherwise noted.

Table 2.
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage VOS VS = 3.3 V @ VCM = 0.5 V and 2.8 V 12 50 μV
−0.3 V < VCM < +1.8 V 40 300 μV
−40°C < TA < +85°C, −0.3 V < VCM < +1.8 V 500 μV
−40°C < TA < +125°C, −0.3 V < VCM < +1.7 V 700 μV
Offset Voltage Drift ∆VOS/∆T −40°C < TA < +125°C 1 4.5 μV/°C
Input Bias Current IB 0.2 1 pA
−40°C < TA < +85°C 50 pA
−40°C < TA < +125°C 500 pA
Input Offset Current IOS 0.1 0.5 pA
−40°C < TA < +85°C 50 pA
−40°C < TA < +125°C 250 pA
Input Voltage Range IVR −0.3 +1.8 V
Common-Mode Rejection Ratio CMRR 0 V < VCM < 1.8 V 80 98 dB
−40°C < TA < +85°C 70 dB
Large Signal Voltage Gain AVO RL = 10 kΩ, 0.5 V < VO < 4.5 V
AD8603 150 3000 V/mV
AD8607/AD8609 100 2000 V/mV
Input Capacitance CDIFF 2.1 pF
CCM 3.8 pF
OUTPUT CHARACTERISTICS
Output Voltage High VOH IL = 1 mA 1.65 1.72 V
−40°C to +125°C 1.6 V
Output Voltage Low VOL IL = 1 mA 38 60 mV
−40°C to +125°C 80 mV
Short-Circuit Current ISC ±10 mA
Closed-Loop Output Impedance ZOUT f = 10 kHz, AV = 1 36 Ω
POWER SUPPLY
Power Supply Rejection Ratio PSRR 1.8 V < VS < 5 V 80 100 dB
Supply Current per Amplifier ISY VO = 0 V 40 50 μA
−40°C < TA < +85°C 60 μA
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kΩ 0.1 V/μs
Settling Time 0.1% tS G = ±1, 1 V step 9.2 μs
Gain Bandwidth Product GBP RL = 100 kΩ 385 kHz
RL = 10 kΩ 316 kHz
Phase Margin ØO RL = 10 kΩ, RL = 100 kΩ 70 Degrees
NOISE PERFORMANCE
Peak-to-Peak Noise en p-p 0.1 Hz to 10 Hz 2.3 3.5 μV
Voltage Noise Density en f = 1 kHz 25 nV/√Hz
f = 10 kHz 22 nV/√Hz
Current Noise Density in f = 1 kHz 0.05 pA/√Hz
Channel Separation CS f = 10 kHz −115 dB
f = 100 kHz −110 dB

Rev. C | Page 4 of 16
 AD8603/AD8607/AD8609

ABSOLUTE MAXIMUM RATINGS

Absolute maximum ratings apply at 25°C, unless otherwise noted. Table 4. Package Characteristics
Package Type θJA1 θJC Unit
Table 3.
5-Lead TSOT (UJ) 207 61 °C/W
Parameter Rating
8-Lead MSOP (RM) 210 45 °C/W
Supply Voltage 6V 8-Lead SOIC_N (R) 158 43 °C/W
Input Voltage GND to VS 14-Lead SOIC_N (R) 120 36 °C/W
Differential Input Voltage ±6 V 14-Lead TSSOP (RU) 180 35 °C/W
Output Short-Circuit Duration to GND Indefinite
1
Storage Temperature Range −65°C to +150°C θJA is specified for the worst-case conditions, that is, θJA is specified for a
device soldered in a circuit board for surface-mount packages.
Lead Temperature (Soldering, 60 sec) 300°C
Operating Temperature Range −40°C to +125°C
Junction Temperature Range −65°C to +150°C ESD CAUTION
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational section of
this specification is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.

Rev. C | Page 5 of 16
AD8603/AD8607/AD8609

TYPICAL PERFORMANCE CHARACTERISTICS

2600 300
VS = 5V VS = 3.3V
2400 250 TA = 25°C
TA = 25°C
2200 VCM = 0V TO 5V 200
2000 150
NUMBER OF AMPLIFIERS

1800
100
1600
50
1400

VOS (µV)
0
1200
–50
1000
–100
800
–150
600
400 –200

200 –250

0 –300

04356-009
04356-006
–270 –210 –150 –90 –30 0 30 90 150 210 270 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
VOS (µV) VCM (V)
(V)

Figure 6. Input Offset Voltage Distribution Figure 9. Input Offset Voltage vs. Common-Mode Voltage

30 400
VS = ±2.5V
TA = –40°C TO +125°C
350
VCM = 0V
25 VS = ±2.5V
300
INPUT BIAS CURRENT (pA)
NUMBERS OF AMPLIFIERS

20
250

15 200

150
10
100

5
50

0 0
04356-007

04356-010
0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 0 25 50 75 100 125
TCVOS (µV/°C) TEMPERATURE (°C)

Figure 7. Input Offset Voltage Drift Distribution Figure 10. Input Bias Current vs. Temperature

300 1000
VS = 5V VS = 5V
250
TA = 25°C TA = 25°C
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

200
100
150

100
50 10
VOS (µV)

0
SOURCE SINK
–50
1
–100
–150
0.1
–200
–250
–300 0.01
04356-008

04356-011

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0.001 0.01 0.1 1 10
VCM (V) LOAD CURRENT (mA)

Figure 8. Input Offset Voltage vs. Common-Mode Voltage Figure 11. Output Voltage to Supply Rail vs. Load Current

Rev. C | Page 6 of 16
 AD8603/AD8607/AD8609
350 1750
VS = 5V VS = ±2.5V, ±0.9V
TA = 25°C 1575
300
1400
OUTPUT VOLTAGE SWING (mV)

VDD – VOH @ 10mA LOAD

250

OUTPUT IMPEDANCE (Ω)

1225
AV = 100
200 1050
VOL @ 10mA LOAD AV = 10
875
AV = 1
150
700

100 525

350
50
VDD – VOH @ 1mA LOAD 175
VOL @ 1mA LOAD
0 0

04356-012

04356-015
–40 –25 –10 5 20 35 50 65 80 95 110 125 100 1k 10k 100k
TEMPERATURE (°C) FREQUENCY (Hz)

Figure 12. Output Voltage Swing vs. Temperature Figure 15. Output Impedance vs. Frequency

100 225 140

VS = ±2.5V VS = ±2.5V
80 RL = 100kΩ 180 120
CL = 20pF
60 Φ = 70.9° 135 100

40 90 80
OPEN-LOOP GAIN (dB)

PHASE (Degree)

20 45 60
CMRR (dB)
0 0 40

–20 –45 20

–40 –90 0
–60 –135 –20

–80 –180 –40

–100 –225 –60

04356-013

04356-016
1k 10k 100k 1M 10M 100 1k 10k 100k
FREQUENCY (Hz) FREQUENCY (Hz)

Figure 13. Open-Loop Gain and Phase vs. Frequency Figure 16. CMRR vs. Frequency

5.0 140
VS = 5V VS = ±2.5V
4.5 120
VIN = 4.9V p-p
TA = 25°C
4.0
OUTPUT VOLTAGE SWING (V p-p)

AV = 1 100

3.5 80

3.0 60
PSRR (dB)

2.5 40

2.0 20

1.5 0

1.0 –20

0.5 –40

0 –60
04356-014

04356-017

0.01 0.1 1 10 100 10 100 1k 10k 100k

FREQUENCY (kHz) FREQUENCY (Hz)

Figure 14. Closed-Loop Output Voltage Swing vs. Frequency Figure 17. PSRR vs. Frequency

Rev. C | Page 7 of 16
AD8603/AD8607/AD8609
60
VS = 5V VS = 5V, 1.8V

50
SMALL SIGNAL OVERSHOOT (%)

VOLTAGE NOISE (1µV/DIV)

40

OS–
30

20

OS+
10

04356-021
04356-018
10 100 1000
LOAD CAPACITANCE (pF) TIME (1s/DIV)

Figure 18. Small Signal Overshoot vs. Load Capacitance Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise

60
VS = ±2.5V VS = 5V
55 RL = 10kΩ
50 CL = 200pF
AV = 1
45

VOLTAGE (50mV/DIV)
SUPPLY CURRENT (µA)

40

35
30
25

20

15
10

04356-022
0
04356-019

–40 –25 –10 5 20 35 50 65 80 95 110 125

TIME (4µs/DIV)
TEMPERATURE (°C)

Figure 19. Supply Current vs. Temperature Figure 22. Small Signal Transient

100
TA = 25°C VS = 5V
90 RL = 10kΩ
CL = 200pF
80 AV = 1

70
SUPPLY CURRENT (µA)

VOLTAGE (1V/DIV)

60

50

40

30

20

10

0
04356-023
04356-020

0 1 2 3 4 5
SUPPLY VOLTAGE (V) TIME (20µs/DIV)

Figure 20. Supply Current vs. Supply Voltage Figure 23. Large Signal Transient

Rev. C | Page 8 of 16
 AD8603/AD8607/AD8609
176
VS = ±2.5V VS = ±2.5V
RL = 10kΩ 154
VOUT (V)

AV = 100

VOLTAGE NOISE DENSITY (nV/√Hz)

+2.5V
VIN = 50mV
132

0V 110

0V 88
VIN (mV)

66

44
–50mV
22

04356-024
0

04356-027
0 1 2 3 4 5 6 7 8 9 10
TIME (4μs/DIV))
(40µs/DIV) FREQUENCY (kHz)
Figure 24. Negative Overload Recovery Figure 27. Voltage Noise Density vs. Frequency

800
VS = ±2.5V 750 VS = 1.8V
RL = 10kΩ TA = 25°C
700
AV = 100 +2.5V VCM = 0V TO 1.8V
650
VOUT (V)

VIN = 50mV
600

NUMBER OF AMPLIFIERS
550
0V 500
450
0V 400
350
300
VIN (mV)

250
200
150
–50mV
100
50
0
04356-025

04356-028
–300 –240 –180 –120 –60 0 60 120 180 240 300
TIME (4µs/DIV) VOS (µV)

Figure 25. Positive Overload Recovery Figure 28. VOS Distribution

168 300
VS = ±2.5V 250 VS = 1.8V
144 TA = 25°C
200
VOLTAGE NOISE DENSITY (nV/√Hz)

150
120
100

96 50
VOS (µV)

0
72 –50

–100
48
–150

–200
24
–250

0 –300
04356-029
04356-026

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 0.3 0.6 0.9 1.2 1.5 1.8
FREQUENCY (kHz) V
VCM
CM(V)
(V)

Figure 26. Voltage Noise Density vs. Frequency Figure 29. Input Offset Voltage vs. Common-Mode Voltage

Rev. C | Page 9 of 16
AD8603/AD8607/AD8609
1000 100 225
VS = 1.8V VS = ±0.9V
TA = 25°C 80 RL = 100kΩ 180
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

CL = 20pF
100 60 Φ = 70° 135

40 90

OPEN-LOOP GAIN (dB)

PHASE (Degrees)
10 20 45
SOURCE
SINK 0 0

1 –20 –45

–40 –90

0.1 –60 –135

–80 –180

0.01 –100 –225

04356-033
04356-030
0.001 0.01 0.1 1 10 1k 10k 100k 1M 10M
LOAD CURRENT (mA) FREQUENCY (Hz)

Figure 30. Output Voltage to Supply Rail vs. Load Current Figure 33. Open-Loop Gain and Phase vs. Frequency

100 140
VS = 1.8V
90 120
VS = 1.8V
80 100
OUTPUT VOLTAGE SWING (mV)

70 80
VDD – VOH @ 1mA LOAD
60 60
CMRR (dB)

50 40
VOL @ 1mA LOAD
40 20

30 0

20 –20

10 –40

0 –60

04356-034
04356-031

–40 –25 –10 5 20 35 50 65 80 95 110 125 100 1k 10k 100k

TEMPERATURE (°C) FREQUENCY (Hz)

Figure 31. Output Voltage Swing vs. Temperature Figure 34. CMRR vs. Frequency

60 1.8

VS = 1.8V
TA = 25°C VS = 1.8V
50 1.5
OUTPUT VOLTAGE SWING (V p-p)

AV = 1 VIN = 1.7V p-p

SMALL SIGNAL OVERSHOOT (%)

TA = 25°C
AV = 1
40 1.2

30 0.9

20 0.6

OS–
10 0.3
OS+
0 0
04356-035
04356-032

10 100 1000 0.01 0.1 1 10 100

LOAD CAPACITANCE (pF) FREQUENCY (kHz)

Figure 32. Small Signal Overshoot vs. Load Capacitance Figure 35. Closed-Loop Output Voltage Swing vs. Frequency

Rev. C | Page 10 of 16
 AD8603/AD8607/AD8609
176
VS = 1.8V VS = ±0.9V
RL = 10kΩ
154
CL = 200pF

VOLTAGE NOISE DENSITY (nV/√Hz)

AV = 1
132
VOLTAGE (50mV/DIV)

110

88

66

44

22

04356-036
0

04356-039
0 1 2 3 4 5 6 7 8 9 10
TIME (4µs/DIV) FREQUENCY (kHz)

Figure 36. Small Signal Transient Figure 39. Voltage Noise Density vs. Frequency

0
VS = ±2.5V, ±0.9V
VS = 1.8V
RL = 10kΩ –20
CL = 200pF
AV = 1

CHANNEL SEPARATION (dB)

–40
VOLTAGE (500mV/DIV)

–60

–80

–100

–120

–140
04356-037

04356-040
100 1k 10k 100k 1M
TIME (20µs/DIV) FREQUENCY (Hz)

Figure 37. Large Signal Transient Figure 40. Channel Separation vs. Frequency

168
VS = ±0.9V

140
VOLTAGE NOISE DENSITY (nV/√Hz)

112

84

56

28

0
04356-038

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
FREQUENCY (kHz)

Figure 38. Voltage Noise Density vs. Frequency

Rev. C | Page 11 of 16
AD8603/AD8607/AD8609

APPLICATIONS
NO PHASE REVERSAL The use of the snubber circuit is usually recommended for unity
gain configurations. Higher gain configurations help improve
The AD8603/AD8607/AD8609 do not exhibit phase inversion the stability of the circuit. Figure 44 shows the same output
even when the input voltage exceeds the maximum input response with the snubber in place.
common-mode voltage. Phase reversal can cause permanent
damage to the amplifier, resulting in system lockups. The
VS = ±0.9V
AD8603/AD8607/AD8609 can handle voltages of up to 1 V VIN = 100mV
CL = 2nF
over the supply. RL = 10kΩ

VS = ±2.5V
VIN VIN = 6V p-p
AV = 1
RL = 10kΩ
VOLTAGE (1V/DIV)

VOUT

04356-042
Figure 42. Output Response to a 2 nF Capacitive Load, Without Snubber

VEE
04356-041

V–
TIME (4µs/DIV) V+ RS
150Ω
Figure 41. No Phase Response + CL
200mV CS

04356-043
– VCC
47pF
INPUT OVERVOLTAGE PROTECTION
If a voltage 1 V higher than the supplies is applied at either Figure 43. Snubber Network
input, the use of a limiting series resistor is recommended. If
both inputs are used, each one should be protected with a VSY = ±0.9V
series resistor. VIN = 100mV
CL = 2nF
RL = 10kΩ
To ensure good protection, the current should be limited to a RS = 150Ω
maximum of 5 mA. The value of the limiting resistor can be CS = 470pF

determined from the following equation:

(VIN − VS)/(RS + 200 Ω) ≤ 5 mA
DRIVING CAPACITIVE LOADS
The AD8603/AD8607/AD8609 are capable of driving large
capacitive loads without oscillating. Figure 42 shows the output
04356-044

of the AD8603/AD8607/AD8609 in response to a 100 mV input

signal, with a 2 nF capacitive load.
Figure 44. Output Response to a 2 nF Capacitive Load with Snubber
Although it is configured in positive unity gain (the worst case),
the AD8603 shows less than 20% overshoot. Simple additional Optimum values for RS and CS are determined empirically;
circuitry can eliminate ringing and overshoot. Table 5 lists a few starting values.

One technique is the snubber network, which consists of a Table 5. Optimum Values for the Snubber Network
series RC and a resistive load (see Figure 43). With the snubber CL (pF) RS (Ω) CS (pF)
in place, the AD8603/AD8607/AD8609 are capable of driving 100 to ~500 500 680
capacitive loads of 2 nF with no ringing and less than 3% 1500 100 330
overshoot. 1600 to ~2000 400 100

Rev. C | Page 12 of 16
 AD8603/AD8607/AD8609
PROXIMITY SENSORS BATTERY-POWERED APPLICATIONS
Proximity sensors can be capacitive or inductive and are used in The AD8603/AD8607/AD8609 are ideal for battery-powered
a variety of applications. One of the most common applications applications. The parts are tested at 5 V, 3.3 V, 2.7 V, and 1.8 V
is liquid level sensing in tanks. This is particularly popular in and are suitable for various applications whether in single or
pharmaceutical environments where a tank must know when to dual supply.
stop filling or mixing a given liquid. In aerospace applications, In addition to their low offset voltage and low input bias, the
these sensors detect the level of oxygen used to propel engines. AD8603/AD8607/AD8609 have a very low supply current of
Whether in a combustible environment or not, capacitive 40 μA, making the parts an excellent choice for portable electronics.
sensors generally use low voltage. The precision and low voltage The TSOT package allows the AD8603 to be used on smaller
of the AD8603/AD8607/AD8609 make the parts an excellent board spaces.
choice for such applications.
PHOTODIODES
COMPOSITE AMPLIFIERS
Photodiodes have a wide range of applications from barcode
A composite amplifier can provide a very high gain in applications scanners to precision light meters and CAT scanners. The very
where high closed-loop dc gains are needed. The high gain low noise and low input bias current of the AD8603/AD8607/
achieved by the composite amplifier comes at the expense of a AD8609 make the parts very attractive amplifiers for I-V
loss in phase margin. Placing a small capacitor, CF, in the feedback conversion applications.
in parallel with R2 (see Figure 45) improves the phase margin.
Picking CF = 50 pF yields a phase margin of about 45° for the Figure 47 shows a simple photodiode circuit. The feedback
values shown in Figure 45. capacitor helps the circuit maintain stability. The signal band-
CF
width can be increased at the expense of an increase in the total
noise; a low-pass filter can be implemented by a simple RC network
R1 R2
at the output to reduce the noise. The signal bandwidth can be
1kΩ VEE 99kΩ
calculated by ½πR2C2, and the closed-loop bandwidth is the
VCC
intersection point of the open-loop gain and the noise gain.
V– AD8603 U5
V+ V+ AD8541
The circuit shown in Figure 47 has a closed-loop bandwidth of
V– 58 kHz and a signal bandwidth of 16 Hz. Increasing C2 to 50 pF
VIN VCC yields a closed-loop bandwidth of 65 kHz, but only 3.2 Hz of
VEE
04356-045

R3 R4 signal bandwidth can be achieved.

1kΩ 99kΩ
C2
Figure 45. High Gain Composite Amplifier 10pF

A composite amplifier can be used to optimize dc and ac

R2
characteristics. Figure 46 shows an example using the AD8603 1000MΩ
and the AD8541. This circuit offers many advantages. The band-
VEE
width is increased substantially, and the input offset voltage and
noise of the AD8541 become insignificant because they are divided V–
by the high gain of the AD8603.
AD8603
The circuit in Figure 46 offers high bandwidth (nearly double R1 C1
1000MΩ 10pF V+
that of the AD8603), high output current, and very low power
04356-047

consumption of less than 100 μA.

VCC
R2
Figure 47. Photodiode Circuit
VEE 100kΩ

R1 V– VCC
1kΩ R3
AD8603 V+ R4
VIN 1kΩ
V– 100Ω
V+ C2 AD8541
VEE C3
VCC
04356-046

Figure 46. Low Power Composite Amplifier

Rev. C | Page 13 of 16
AD8603/AD8607/AD8609

OUTLINE DIMENSIONS
2.90 BSC

5 4

1.60 BSC 2.80 BSC

1 2 3

PIN 1
0.95 BSC

*0.90 1.90
BSC
0.87
0.84

*1.00 MAX 0.20

0.08
8°
0.10 MAX 0.50 SEATING 4° 0.60
0.30 PLANE 0° 0.45
0.30

*COMPLIANT TO JEDEC STANDARDS MO-193-AB WITH

THE EXCEPTION OF PACKAGE HEIGHT AND THICKNESS.

Figure 48. 5-Lead Thin Small Outline Transistor Package [TSOT]

(UJ-5)
Dimensions shown in millimeters

3.20
3.00
2.80

8 5 5.15
3.20
4.90
3.00
4.65
2.80 1
4

PIN 1
0.65 BSC
0.95
0.85 1.10 MAX
0.75
0.80
0.15 0.38 8° 0.60
0.23
0.00 0.22 0° 0.40
0.08
COPLANARITY SEATING
0.10 PLANE

COMPLIANT TO JEDEC STANDARDS MO-187-AA

Figure 49. 8-Lead Mini Small Outline Package [MSOP]

(RM-8)
Dimensions shown in millimeters

Rev. C | Page 14 of 16
 AD8603/AD8607/AD8609
5.00 (0.1968)
4.80 (0.1890)

8 5
4.00 (0.1574) 6.20 (0.2441)
3.80 (0.1497) 1 5.80 (0.2284)
4

1.27 (0.0500) 0.50 (0.0196)

BSC 45°
1.75 (0.0688) 0.25 (0.0099)
0.25 (0.0098) 1.35 (0.0532)
8°
0.10 (0.0040) 0°
COPLANARITY 0.51 (0.0201)
0.10 1.27 (0.0500)
0.31 (0.0122) 0.25 (0.0098)
SEATING 0.40 (0.0157)
PLANE 0.17 (0.0067)

COMPLIANT TO JEDEC STANDARDS MS-012-A A

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS

012407-A
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

Figure 50. 8-Lead Standard Small Outline Package [SOIC_N]

(R-8)
Dimensions shown in millimeters and (inches)

8.75 (0.3445)
8.55 (0.3366)

14 8
4.00 (0.1575) 6.20 (0.2441)
1
3.80 (0.1496) 7 5.80 (0.2283)

1.27 (0.0500) 0.50 (0.0197)

BSC 45°
1.75 (0.0689) 0.25 (0.0098)
0.25 (0.0098) 8°
1.35 (0.0531)
0.10 (0.0039) 0°
COPLANARITY SEATING
0.10 0.51 (0.0201) 0.25 (0.0098) 1.27 (0.0500)
PLANE
0.31 (0.0122) 0.17 (0.0067) 0.40 (0.0157)

COMPLIANT TO JEDEC STANDARDS MS-012-AB

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS 060606-A
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

Figure 51. 14-Lead Standard Small Outline Package [SOIC_N]

(R-14)
Dimensions shown in millimeters and (inches)

5.10
5.00
4.90

14 8

4.50
4.40 6.40
BSC
4.30

1 7

PIN 1
1.05 0.65
1.00 BSC
0.20
0.80 1.20
MAX 0.09 0.75
8° 0.60
0.15 0.30 0° 0.45
0.05 SEATING
0.19 PLANE COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1

Figure 52. 14-Lead Thin Shrink Small Outline Package [TSSOP]

(RU-14)
Dimensions shown in millimeters

Rev. C | Page 15 of 16
AD8603/AD8607/AD8609
ORDERING GUIDE
Model Temperature Range Package Description Package Option Branding
AD8603AUJ-R2 −40°C to +125°C 5-Lead TSOT UJ-5 BFA
AD8603AUJ-REEL −40°C to +125°C 5-Lead TSOT UJ-5 BFA
AD8603AUJ-REEL7 −40°C to +125°C 5-Lead TSOT UJ-5 BFA
AD8603AUJZ-R2 1 −40°C to +125°C 5-Lead TSOT UJ-5 A0X
AD8603AUJZ-REEL1 −40°C to +125°C 5-Lead TSOT UJ-5 A0X
AD8603AUJZ-REEL71 −40°C to +125°C 5-Lead TSOT UJ-5 A0X
AD8607ARM-R2 −40°C to +125°C 8-Lead MSOP RM-8 A00
AD8607ARM-REEL −40°C to +125°C 8-Lead MSOP RM-8 A00
AD8607ARMZ-R21 −40°C to +125°C 8-Lead MSOP RM-8 A0G
AD8607ARMZ-REEL1 −40°C to +125°C 8-Lead MSOP RM-8 A0G
AD8607AR −40°C to +125°C 8-Lead SOIC_N R-8
AD8607AR-REEL −40°C to +125°C 8-Lead SOIC_N R-8
AD8607AR-REEL7 −40°C to +125°C 8-Lead SOIC_N R-8
AD8607ARZ1 −40°C to +125°C 8-Lead SOIC_N R-8
AD8607ARZ-REEL1 −40°C to +125°C 8-Lead SOIC_N R-8
AD8607ARZ-REEL71 −40°C to +125°C 8-Lead SOIC_N R-8
AD8609AR −40°C to +125°C 14-Lead SOIC_N R-14
AD8609AR-REEL −40°C to +125°C 14-Lead SOIC_N R-14
AD8609AR-REEL7 −40°C to +125°C 14-Lead SOIC_N R-14
AD8609ARZ1 −40°C to +125°C 14-Lead SOIC_N R-14
AD8609ARZ-REEL1 −40°C to +125°C 14-Lead SOIC_N R-14
AD8609ARZ-REEL71 −40°C to +125°C 14-Lead SOIC_N R-14
AD8609ARU −40°C to +125°C 14-Lead TSSOP RU-14
AD8609ARU-REEL −40°C to +125°C 14-Lead TSSOP RU-14
AD8609ARUZ1 −40°C to +125°C 14-Lead TSSOP RU-14
AD8609ARUZ-REEL1 −40°C to +125°C 14-Lead TSSOP RU-14
1
Z = RoHS Compliant Part.

©2003–2008 Analog Devices, Inc. All rights reserved. Trademarks and

registered trademarks are the property of their respective owners.
D04356-0-6/08(C)

Rev. C | Page 16 of 16