ANALOG DEVICES AD 8607 ARZ Datasheet

Precision Micropower, Low Noise CMOS,

Rail-to-Rail Input/Output Operational Amplifiers

FEATURES

Low offset voltage: 50 μV maximum
Low input bias current: 1 pA maximum
Single-supply operation: 1.8 V to 5 V
Low noise: 22 nV/√Hz
Micropower: 50 μA maximum
Low distortion
No phase reversal
Unity gain stable

APPLICATIONS

Battery-powered instrumentation
Multipole filters
Sensors
Low power ASIC input or output amplifiers

GENERAL DESCRIPTION

The AD8603/AD8607/AD8609 are single/dual/quad micro­power rail-to-rail input and output amplifiers, respectively, that
feature very low offset voltage as well as low input voltage and
current noise.

These amplifiers use a patented trimming technique that achieves
superior precision without laser trimming. The parts are fully
specified to operate from 1.8 V to 5.0 V single supply or from
±0.9 V to ±2.5 V dual supply. The combination of low offsets, low
noise, very low input bias currents, and low power consumption
makes the AD8603/AD8607/AD8609 especially useful in portable
and loop-powered instrumentation.

The ability to swing rail to rail at both the input and output
enables designers to buffer CMOS ADCs, DACs, ASICs, and
other wide output swing devices in low power, single-supply
systems.

The AD8603 is available in a tiny 5-lead TSOT package. The
AD8607 is available in 8-lead MSOP and 8-lead SOIC packages.
The AD8609 is available in 14-lead TSSOP and 14-lead SOIC
packages.

AD8603/AD8607/AD8609

PIN CONFIGURATIONS

OUT

1

AD8603

TOP VIEW

V–

2

(Not to Scale)

+IN

3

Figure 1. 5-Lead TSOT (UJ Suffix)

1

OUT A

–IN A

+IN A

V–

AD8607

2

TOP VIEW

3

(Not to Scale)

4

Figure 2. 8-Lead MSOP (RM Suffix)

OUT A

1

V–

AD8607

2

3

TOP VIEW

(Not to Scale)

4

–IN A

+IN A

Figure 3. 8-Lead SOIC (R Suffix)

1

OUT A

2

–IN A

3

+IN A

V+

+IN B

–IN B

OUT B

AD8609

TOP VIEW

4

(Not to Scale)

5

6

7

Figure 4. 14-Lead TSSOP (RU Suffix)

OUT A

1

2

–IN A

3

+IN A

+IN B

–IN B

OUT B

V+

AD8609

TOP VIEW

4

(Not to Scale)

5

6

7

Figure 5. 14-Lead SOIC (R Suffix)

5

4

8

7

6

5

8

7

6

5

14

13

12

11

10

14

13

12

11

10

9

8

V+

OUT B

–IN B

+IN B

9

8

V+

–IN

V+

OUT B

–IN B

+IN B

OUT D

–IN D

+IN D

V–

+IN C

–IN C

OUT C

OUT D

–IN D

+IN D

V–

+IN C

–IN C

OUT C

04356-001

04356-002

04356-003

04356-004

4356-005

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
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2003–2008 Analog Devices, Inc. All rights reserved.

AD8603/AD8607/AD8609

TABLE OF CONTENTS

Features .............................................................................................. 1

Applicat ions ....................................................................................... 1

General Description ......................................................................... 1

Pin Configurations ........................................................................... 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Electrical Characteristics ............................................................. 3

Absolute Maximum Ratings ............................................................ 5

ESD Caution .................................................................................. 5

Typical Performance Characteristics ............................................. 6

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

Applicat ions ..................................................................................... 12

No Phase Reversal ...................................................................... 12

Input Overvoltage Protection ................................................... 12

Driving Capacitive Loads .......................................................... 12

Proximity Sensors ....................................................................... 13

Composite Amplifiers ................................................................ 13

Battery-Powered Applications .................................................. 13

Photodiodes ................................................................................ 13

Outline Dimensions ....................................................................... 14

Ordering Guide .......................................................................... 16

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 V

−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 R

AD8603 400 1000 V/mV
AD8607/AD8609 250 450 V/mV

Input Capacitance C

C

1.9 pF

DIFF

2.5 pF

CM

OUTPUT CHARACTERISTICS

Output Voltage High VOH I

−40°C to +125°C 4.9 V

I

−40°C to +125°C 4.50 V
Output Voltage Low VOL I

−40°C to +125°C 50 mV

I

−40°C to +125°C 330 mV
Short-Circuit Current ISC ±70 mA
Closed-Loop Output Impedance Z

f = 10 kHz, AV = 1 36 Ω

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR 1.8 V < VS < 5 V 80 100 dB
Supply Current per Amplifier ISY V

−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

R

Phase Margin ØO R

NOISE PERFORMANCE

Peak-to-Peak Noise e

0.1 Hz to 10 Hz 2.3 3.5 μV

n p-p

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

= 3.3 V @ VCM = 0.5 V and 2.8 V 12 50 μV

S

= 10 kΩ, 0.5 V < VO < 4.5 V

L

= 1 mA 4.95 4.97 V

L

= 10 mA 4.65 4.97 V

L

= 1 mA 16 30 mV

L

= 10 mA 160 250 mV

L

= 0 V 40 50 μA

O

= 10 kΩ 316 kHz

L

= 10 kΩ, RL = 100 kΩ 70 Degrees

L

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 V

−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 R

AD8603 150 3000 V/mV
AD8607/AD8609 100 2000 V/mV

Input Capacitance C

C

2.1 pF

DIFF

3.8 pF

CM

OUTPUT CHARACTERISTICS

Output Voltage High VOH I

−40°C to +125°C 1.6 V
Output Voltage Low VOL I

−40°C to +125°C 80 mV
Short-Circuit Current ISC ±10 mA
Closed-Loop Output Impedance Z

f = 10 kHz, AV = 1 36 Ω

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR 1.8 V < VS < 5 V 80 100 dB
Supply Current per Amplifier ISY V

−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

R

Phase Margin ØO R

NOISE PERFORMANCE

Peak-to-Peak Noise e

0.1 Hz to 10 Hz 2.3 3.5 μV

n p-p

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

= 3.3 V @ VCM = 0.5 V and 2.8 V 12 50 μV

S

= 10 kΩ, 0.5 V < VO < 4.5 V

L

= 1 mA 1.65 1.72 V

L

= 1 mA 38 60 mV

L

= 0 V 40 50 μA

O

= 10 kΩ 316 kHz

L

= 10 kΩ, RL = 100 kΩ 70 Degrees

L

Rev. C | Page 4 of 16

AD8603/AD8607/AD8609

ABSOLUTE MAXIMUM RATINGS

Absolute maximum ratings apply at 25°C, unless otherwise noted.

Table 3.

Parameter Rating

Supply Voltage 6 V
Input Voltage GND to VS
Differential Input Voltage ±6 V
Output Short-Circuit Duration to GND Indefinite
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 60 sec) 300°C
Operating Temperature Range −40°C to +125°C
Junction Temperature Range −65°C to +150°C

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.

Table 4. Package Characteristics

Package Type θ

5-Lead TSOT (UJ) 207 61 °C/W
8-Lead MSOP (RM) 210 45 °C/W
8-Lead SOIC_N (R) 158 43 °C/W
14-Lead SOIC_N (R) 120 36 °C/W
14-Lead TSSOP (RU) 180 35 °C/W

1

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.

1

θJC Unit

JA

ESD CAUTION

Rev. C | Page 5 of 16

AD8603/AD8607/AD8609

TYPICAL PERFORMANCE CHARACTERISTICS

300

VS = 3.3V

250

T

= 25°C

A

200

150

100

50

0

(µV)

OS

–50

V

–100

–150

–200

–250

–300

0

0.9 2.1 3.0

0.60.3 1. 5 2.72. 41.81.2

VCM(V)

VCM (V)

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

400

350

300

250

VS = ±2.5V

3.3

04356-009

NUMBER OF AMPLIFIERS

2600

2400

2200

2000

1800

1600

1400

1200

1000

800

600

400

200

VS = 5V
T

= 25°C

A

V

= 0V TO 5V

CM

0

–270

–210

–150 –30 30 90 210 270–90

0150

VOS (µV)

Figure 6. Input Offset Voltage Distribution

30

25

20

VS = ±2.5V
T

= –40°C TO +125° C

A

V

= 0V

CM

04356-006

15

10

NUMBERS OF AMPL IFIERS

5

0

0

0.4 0.8 1.2 2.0 2.4 2.8 3.6 4.0 4.4 4.8 5.2

1.6 3.2
TCVOS (µV/°C)

Figure 7. Input Offset Voltage Drift Distribution

300

VS = 5V

250

T

= 25°C

200

150

100

(µV)

OS

–50

V

–100

–150

–200

–250

–300

A

50

0

0

1.5 3.5 5.0

1.00.5 2.5 4.54.03.02.0
VCM (V)

Figure 8. Input Offset Voltage vs. Common-Mode Voltage

200

150

100

INPUT BIAS CURRENT (pA)

50

0

0

04356-007

25 75

50 100 125

TEMPERATURE (°C)

4356-010

Figure 10. Input Bias Current vs. Temperature

1000

VS = 5V

= 25°C

T

A

100

10

1

0.1

OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

0.01

04356-008

0.001

SOURCE

0.01 0.1 1
LOAD CURRENT (mA)

SINK

10

04356-011

Figure 11. Output Voltage to Supply Rail vs. Load Current

Rev. C | Page 6 of 16

AD8603/AD8607/AD8609

350

V

= 5V

S

T

= 25°C

A

300

– VOH@ 10mA LOAD

V

250

200

150

100

OUTPUT VOLTAGE SWING (mV)

50

DD

@ 10mA LOAD

V

OL

– VOH@ 1mA LOAD

V

DD

0

–25 –10 125

–40

20 35 50 65 80 95 1105
TEMPERATURE (°C)

VOL@ 1mA LOAD

Figure 12. Output Voltage Swing vs. Temperature

100

80

60

40

20

0

–20

–40

OPEN-LOOP GAIN (dB)

–60

–80

–100

1k 10k 100k 1M 10M

FREQUENCY ( Hz)

VS = ±2.5V
R

L

C

L

Φ = 70.9°

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

5.0

VS = 5V

4.5
= 4.9V p-p

V

IN

= 25°C

T

A

4.0

= 1

A

V

3.5

3.0

2.5

2.0

1.5

1.0

OUTPUT VOLTAGE SWING (V p-p)

0.5

0

0.01

0.1 1 100
FREQUENCY ( kHz)

10

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

= 100kΩ
= 20pF

225

180

135

90

45

0

–45

–90

–135

–180

–225

04356-012

PHASE (Degree)

04356-013

04356-014

1750

VS= ±2.5V, ±0.9V

1575

1400

1225

1050

875

700

525

OUTPUT IMPEDANCE (Ω)

350

175

0

100

AV = 100

AV = 10

1k 100k

FREQUENCY (Hz)

10k

Figure 15. Output Impedance vs. Frequency

140

120

100

80

60

40

20

CMRR (dB)

0

–20

–40

–60

100

1k 10k

FREQUENCY ( Hz)

Figure 16. CMRR vs. Frequency

140

120

100

80

60

40

20

PSRR (dB)

0

–20

–40

–60

10 100 1k 10k 100k

FREQUENCY (Hz)

Figure 17. PSRR vs. Frequency

= 1

A

V

VS = ±2.5V

VS = ±2.5V

100k

04356-015

04356-016

04356-017

Rev. C | Page 7 of 16

AD8603/AD8607/AD8609

A

T

T

60

VS = 5V

50

40

30

L OVERSHOOT (%)

20

10

SMALL SIGN

0

10

LOAD CAPACITANCE (pF)

OS–

OS+

100 1000

Figure 18. Small Signal Overshoot vs. Load Capacitance

60

VS = ±2.5V

55

50

45

40

35

30

25

20

SUPPLY CURRENT (µA)

15

10

5

0

–40

–10 5

20 80–25 50

35 65

TEMPERATURE (°C)

Figure 19. Supply Current vs. Temperature

100

90

80

70

60

50

40

30

SUPPLY CURRENT (µA)

20

10

0

0

1

2453

SUPPLY VOLTAGE (V)

Figure 20. Supply Current vs. Supply Voltage

95 110 125

TA = 25°C

04356-018

4356-019

04356-020

VS = 5V, 1.8V

VOLTAGE NOISE (1µV/DIV)

TIME (1s/DIV)

Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise

VS = 5V
R

= 10kΩ

L

C

= 200pF

L

A

= 1

V

AGE (50mV/DI V)

VOL

TIME (4µs/DIV)

Figure 22. Small Signal Transient

VS = 5V
R

= 10kΩ

L

C

= 200pF

L

A

= 1

V

AGE (1V/DIV)

VOL

TIME (20µs/DIV)

Figure 23. Large Signal Transient

04356-021

04356-022

04356-023

Rev. C | Page 8 of 16

AD8603/AD8607/AD8609

√

√

VS= ±2.5V
R

= 10kΩ

L

A

= 100

(V)

+2.5V

OUT

0V

0V

(mV) V

IN

V

–50mV

μ

s/DIV))

TIME (4

TIME (40µs/DIV)

V

V
IN

= 50mV

04356-024

Figure 24. Negative Overload Recovery

VS = ±2.5V
R

= 10kΩ

L

A

= 100

V

V

= 50mV

(V)

OUT

(mV) V

IN

V

IN

0V

0V

–50mV

TIME (4µs/DIV)

+2.5V

04356-025

Figure 25. Positive Overload Recovery

168

144

Hz)

120

96

72

48

VOLTAGE NOISE DENSITY (nV/

24

0

0.1 1.00.2 0.3 0.4 0. 5 0.6 0.7 0.8 0.90
FREQUENCY (kHz)

VS = ±2.5V

04356-026

Figure 26. Voltage Noise Density vs. Frequency

176

154

Hz)

132

110

88

66

44

VOLTAGE NOISE DENSITY (nV/

22

0

11234567890

FREQUENCY (kHz)

VS = ±2.5V

Figure 27. Voltage Noise Density vs. Frequency

NUMBER OF AMPLIFIERS

800
750

700
650

600

550

500

450
400

350
300

250

200

150

100

50

0
–300

–240 60 240

–180 –120

Figure 28. V

–60

VOS (µV)

OS

0

Distribution

VS = 1.8V
T

= 25°C

A

V

CM

120

= 0V TO 1. 8V

180

300

VS = 1.8V

250

T

= 25°C

A

200

150

100

50

0

(µV)

OS

–50

V

–100

–150

–200

–250

–300

0

0.9

0.60.3 1.5 1.81.2

VCM(V)

VCM (V)

Figure 29. Input Offset Voltage vs. Common-Mode Voltage

0

04356-027

300

04356-028

9
2
0

­6
5
3
4
0

Rev. C | Page 9 of 16

AD8603/AD8607/AD8609

A

1000

VS = 1.8V
T

= 25°C

A

100

OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

0.01

10

1

0.1

0.001

SOURCE

0.01 0.1 1
LOAD CURRENT (mA)

SINK

Figure 30. Output Voltage to Supply Rail vs. Load Current

100

90

80

70

60

50

40

30

20

OUTPUT VOLTAGE SWING (mV)

10

0

–40

–25

VS = 1.8V

–10

35

20

5

TEMPERATURE (°C)

VDD – VOH@ 1mA LOAD

VOL@ 1mA LOAD

50 65 80 95 110

Figure 31. Output Voltage Swing vs. Temperature

60

VS = 1.8V
T

= 25°C

A

50

A

= 1

V

40

125

10

04356-030

04356-031

100

80

60

40

20

0

–20

–40

OPEN-LOOP GAIN (dB)

–60

–80

–100

1k 10k 100k 1M 10M

FREQUENCY ( Hz)

VS = ±0.9V
R
C
Φ = 70°

Figure 33. Open-Loop Gain and Phase vs. Frequency

140

VS= 1.8V

120

100

80

60

40

20

CMRR (dB)

0

–20

–40

–60

100 1k 10k 100k

FREQUENCY ( Hz)

Figure 34. CMRR vs. Frequency

1.8

VS= 1.8V

1.5
V

= 1.7V p-p

IN

T

= 25°C

A

A

= 1

V

1.2

= 100kΩ

L

= 20pF

L

225

180

135

90

45

0

–45

–90

–135

–180

–225

PHASE (Degrees)

04356-033

04356-034

30

L OVERSHOOT (%)

20

OS–

10

SMALL SIGN

0

10

LOAD CAPACITANCE (pF)

OS+

100 1000

Figure 32. Small Signal Overshoot vs. Load Capacitance

04356-032

0.9

0.6

OUTPUT VOLTAGE SWING (V p-p)

0.3

0

0.01 0.1 1 10010
FREQUENCY (kHz )

Figure 35. Closed-Loop Output Voltage Swing vs. Frequency

04356-035

Rev. C | Page 10 of 16

AD8603/AD8607/AD8609

√

√

R
A

VS = 1.8V
R

= 10kΩ

L

C

= 200pF

L

A

= 1

V

VOLTAGE (50mV/DIV)

TIME (4µs/DIV)

04356-036

Figure 36. Small Signal Transient

VS = 1.8V
R

= 10kΩ

L

C

= 200pF

L

A

= 1

V

176

154

Hz)

132

110

88

66

44

VOLTAGE NOISE DENSITY (nV/

22

0

11234567890

FREQUENCY (kHz)

Figure 39. Voltage Noise Density vs. Frequency

0

–20

–40

TION (dB)

–60

VS = ±0.9V

VS = ±2.5V, ±0.9V

0

04356-039

–80

VOLTAGE (500mV/DIV)

TIME (20µs/DIV)

04356-037

Figure 37. Large Signal Transient

168

140

Hz)

112

84

56

28

VOLTAGE NOISE DENSITY (nV/

0

0.1 1.00.2 0.3 0.4 0.5 0. 6 0.7 0.8 0. 90
FREQUENCY (kHz)

VS = ±0.9V

04356-038

–100

CHANNEL SEPA

–120

–140

100

1k 10k 100k

FREQUENCY ( Hz)

1M

04356-040

Figure 40. Channel Separation vs. Frequency

Figure 38. Voltage Noise Density vs. Frequency

Rev. C | Page 11 of 16

AD8603/AD8607/AD8609

APPLICATIONS

NO PHASE REVERSAL

The AD8603/AD8607/AD8609 do not exhibit phase inversion
even when the input voltage exceeds the maximum input
common-mode voltage. Phase reversal can cause permanent
damage to the amplifier, resulting in system lockups. The
AD8603/AD8607/AD8609 can handle voltages of up to 1 V
over the supply.

VS = ±2.5V

= 6V p-p

V

V

IN

V

OUT

VOLTAGE (1V/DIV)

TIME (4µs/DIV)

Figure 41. No Phase Response

IN

A

V

= 10kΩ

R

L

= 1

04356-041

INPUT OVERVOLTAGE PROTECTION

If a voltage 1 V higher than the supplies is applied at either
input, the use of a limiting series resistor is recommended. If
both inputs are used, each one should be protected with a
series resistor.

To ensure good protection, the current should be limited to a
maximum of 5 mA. The value of the limiting resistor can be
determined from the following equation:

(V

− VS)/(RS + 200 Ω) ≤ 5 mA

IN

DRIVING CAPACITIVE LOADS

The AD8603/AD8607/AD8609 are capable of driving large
capacitive loads without oscillating. Figure 42 shows the output
of the AD8603/AD8607/AD8609 in response to a 100 mV input
signal, with a 2 nF capacitive load.

Although it is configured in positive unity gain (the worst case),
the AD8603 shows less than 20% overshoot. Simple additional
circuitry can eliminate ringing and overshoot.

One technique is the snubber network, which consists of a
series RC and a resistive load (see Figure 43). With the snubber
in place, the AD8603/AD8607/AD8609 are capable of driving
capacitive loads of 2 nF with no ringing and less than 3%
overshoot.

The use of the snubber circuit is usually recommended for unity
gain configurations. Higher gain configurations help improve
the stability of the circuit. Figure 44 shows the same output
response with the snubber in place.

VS = ±0.9V
V

= 100mV

IN

C

= 2nF

L

R

= 10kΩ

L

4356-042

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

V

EE

V–
V+

R

S

200mV

+
–

150Ω

C

S

V

CC

47pF

C

L

04356-043

Figure 43. Snubber Network

VSY = ±0.9V
V

= 100mV

IN

C

= 2nF

L

R

= 10kΩ

L

R

= 150Ω

S

C

= 470pF

S

04356-044

Figure 44. Output Response to a 2 nF Capacitive Load with Snubber

Optimum values for RS and CS are determined empirically;
Tabl e 5 lists a few starting values.

Table 5. Optimum Values for the Snubber Network

CL (pF) RS (Ω)

CS (pF)

100 to ~500 500 680
1500 100 330
1600 to ~2000 400 100

Rev. C | Page 12 of 16

AD8603/AD8607/AD8609

PROXIMITY SENSORS

Proximity sensors can be capacitive or inductive and are used in
a variety of applications. One of the most common applications
is liquid level sensing in tanks. This is particularly popular in
pharmaceutical environments where a tank must know when to
stop filling or mixing a given liquid. In aerospace applications,
these sensors detect the level of oxygen used to propel engines.
Whether in a combustible environment or not, capacitive
sensors generally use low voltage. The precision and low voltage
of the AD8603/AD8607/AD8609 make the parts an excellent
choice for such applications.

COMPOSITE AMPLIFIERS

A composite amplifier can provide a very high gain in applications
where high closed-loop dc gains are needed. The high gain
achieved by the composite amplifier comes at the expense of a
loss in phase margin. Placing a small capacitor, C
in parallel with R2 (see Figure 45) improves the phase margin.
Picking C

= 50 pF yields a phase margin of about 45° for the

F

values shown in Figure 45.

C

F

R1

1kΩ

V

EE

V

IN

–

V

V+

99kΩ

AD8603

V

CC

R2

R3 R4

V

V

Figure 45. High Gain Composite Amplifier

A composite amplifier can be used to optimize dc and ac
characteristics. Figure 46 shows an example using the AD8603
and the AD8541. This circuit offers many advantages. The band­width is increased substantially, and the input offset voltage and
noise of the AD8541 become insignificant because they are divided
by the high gain of the AD8603.

The circuit in Figure 46 offers high bandwidth (nearly double
that of the AD8603), high output current, and very low power
consumption of less than 100 μA.

V

EE

R1

V–

1kΩ

V

IN

AD8603

V+

V

CC

R3

1kΩ

C2

Figure 46. Low Power Composite Amplifier

F

CC

U5

V+

AD8541

V

–

EE

99kΩ1kΩ

R2

100kΩ

V

CC

V+
V

–

AD8541

V

EE

, in the feedback

04356-045

R4

100Ω

C3

04356-046

BATTERY-POWERED APPLICATIONS

The AD8603/AD8607/AD8609 are ideal for battery-powered
applications. The parts are tested at 5 V, 3.3 V, 2.7 V, and 1.8 V
and are suitable for various applications whether in single or
dual supply.

In addition to their low offset voltage and low input bias, the
AD8603/AD8607/AD8609 have a very low supply current of
40 μA, making the parts an excellent choice for portable electronics.
The TSOT package allows the AD8603 to be used on smaller
board spaces.

PHOTODIODES

Photodiodes have a wide range of applications from barcode
scanners to precision light meters and CAT scanners. The very
low noise and low input bias current of the AD8603/AD8607/
AD8609 make the parts very attractive amplifiers for I-V
conversion applications.

Figure 47 shows a simple photodiode circuit. The feedback
capacitor helps the circuit maintain stability. The signal band­width 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
at the output to reduce the noise. The signal bandwidth can be
calculated by ½πR2C2, and the closed-loop bandwidth is the
intersection point of the open-loop gain and the noise gain.

The circuit shown in Figure 47 has a closed-loop bandwidth of
58 kHz and a signal bandwidth of 16 Hz. Increasing C2 to 50 pF
yields a closed-loop bandwidth of 65 kHz, but only 3.2 Hz of
signal bandwidth can be achieved.

C2

10pF

R2

1000MΩ

V

EE

V–

C1

R1

1000MΩ

10pF

Figure 47. Photodiode Circuit

AD8603

V+

V

CC

04356-047

Rev. C | Page 13 of 16

AD8603/AD8607/AD8609

OUTLINE DIMENSIONS

2.90 BSC

54

0.50

0.30

2.80 BSC

0.95 BSC

*

1.00 MAX

SEATING
PLANE

(UJ-5)

0.20

0.08

8°
4°
0°

0.60

0.45

0.30

1.60 BSC

123

PIN 1

*

0.90

0.87

0.84

0.10 MAX

*

COMPLIANT TO JEDEC STANDARDS MO-193-AB WITH

THE EXCEPTION OF PACKAGE HEIGHT AND THICKNESS.

1.90

BSC

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

Dimensions shown in millimeters

3.20

3.00

2.80

8

5

4

SEATING
PLANE

5.15

4.90

4.65

1.10 MAX

0.23

0.08

8°
0°

0.80

0.60

0.40

3.20

3.00

1

2.80

PIN 1

0.65 BSC

0.95

0.85

0.75

0.15

0.38

0.00

0.22

COPLANARITY

0.10

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

4.00 (0.1574)

3.80 (0.1497)

0.25 (0.0098)

0.10 (0.0040)

COPLANARITY

0.10

CONTROLL ING DIMENSI ONS ARE IN MILLIMETERS; INCH DI MENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRI ATE FOR USE IN DESIGN.

5.00 (0.1968)

4.80 (0.1890)

85

1

1.27 (0.0500)

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012-A A

BSC

6.20 (0.2441)

5.80 (0.2284)

4

1.75 (0.0688)

1.35 (0.0532)

0.51 (0.0201)

0.31 (0.0122)

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0196)

0.25 (0.0099)

8°
0°

1.27 (0.0500)

0.40 (0.0157)

45°

012407-A

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)

4.00 (0.1575)

3.80 (0.1496)

14

1

8

6.20 (0.2441)

5.80 (0.2283)

7

0.25 (0.0098)

0.10 (0.0039)

COPLANARIT Y

0.10

CONTROLL ING DIMENSIONS ARE IN MILLIMETERS; INCH DI MENSIONS
(IN PARENTHESES) ARE ROUNDED-O FF MIL LIMETE R EQUIVALENTS FOR
REFERENCE ON LY AND ARE NOT APPROPRI ATE FOR USE IN DESIGN.

1.27 (0.0500)
BSC

0.51 (0.0201)

0.31 (0.0122)

COMPLIANT TO JEDEC STANDARDS MS-012-AB

1.75 (0.0689)

1.35 (0.0531)

SEATING
PLANE

8°
0°

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0197)

0.25 (0.0098)

1.27 (0.0500)

0.40 (0.0157)

45°

060606-A

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

(R-14)

Dimensions shown in millimeters and (inches)

5.10

5.00

4.90

1.05

1.00

0.80

4.50

4.40

4.30

PIN 1

14

0.65

BSC

0.15

0.05

COMPLIANT TO JEDEC STANDARDS MO-153-AB-1

0.30

0.19

8

6.40

BSC

71

1.20
MAX

SEATING
PLANE

0.20

0.09

COPLANARITY

0.10

8°
0°

0.75

0.60

0.45

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
AD8603AUJZ-REEL
AD8603AUJZ-REEL7
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-R2
AD8607ARMZ-REEL
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
AD8607ARZ
AD8607ARZ-REEL
AD8607ARZ-REEL7
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
AD8609ARZ
AD8609ARZ-REEL
AD8609ARZ-REEL7
AD8609ARU −40°C to +125°C 14-Lead TSSOP RU-14
AD8609ARU-REEL −40°C to +125°C 14-Lead TSSOP RU-14
AD8609ARUZ
AD8609ARUZ-REEL

1

Z = RoHS Compliant Part.

1

−40°C to +125°C 5-Lead TSOT UJ-5 A0X

1

−40°C to +125°C 5-Lead TSOT UJ-5 A0X

1

−40°C to +125°C 5-Lead TSOT UJ-5 A0X

1

−40°C to +125°C 8-Lead MSOP RM-8 A0G

1

−40°C to +125°C 8-Lead MSOP RM-8 A0G

1

−40°C to +125°C 8-Lead SOIC_N R-8

1

−40°C to +125°C 8-Lead SOIC_N R-8

1

−40°C to +125°C 8-Lead SOIC_N R-8

1

−40°C to +125°C 14-Lead SOIC_N R-14

1

−40°C to +125°C 14-Lead SOIC_N R-14

1

−40°C to +125°C 14-Lead SOIC_N R-14

1

−40°C to +125°C 14-Lead TSSOP RU-14

1

−40°C to +125°C 14-Lead TSSOP RU-14

©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