Datasheet AD8603 Datasheet (Analog Devices)

Precision Micropower Low Noise CMOS Rail-

to-Rail Input/Output Operational Amplifiers

FEATURES

Low offset voltage: 50 µV max Low input bias current: 1 pA max Single-supply operation: 1.8 V to 5 V Low noise: 22 nV/√Hz Micropower: 50 µA max 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 features 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 make 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-23 package. The AD8607 is available in 8-lead MSOP and SOIC packages. The AD8609 is available in 14-lead TSSOP and SOIC packages.

AD8603/AD8607/AD8609

PIN CONFIGURATIONS

V+

1

OUT

AD8603

V–

2

TOP VIEW

(Not to Scale)

+IN

3

Figure 1. 5-Lead TSOT-23 (UJ Suffix)

IN A

V–

1

AD8607

45

OUT A

–

+IN A

Figure 2. 8-Lead MSOP (RM Suffix)

OUT A

1

–IN A

2

+IN A

AD8607

3

V–

4

Figure 3. 8-Lead SOIC (R Suffix)

OUT A

–

+IN A

+IN B

–

OUT B

IN A

IN B

1

AD8609

V+

7

Figure 4. 14-Lead TSSOP (RU Suffix)

1

OUT A

2

–

IN A

3

+IN A

AD8609

4

V+

5

+IN B

6

–IN B

7

OUT B

Figure 5. 14-Lead SOIC (R Suffix)

5

–IN

4

04356-0-001

8

V+ OUT B

–IN B

+IN B

04356-0-045

V+

8

OUT B

7

6

–IN B

+IN B

5

04356-0-047

OUT D

14

–

IN D

+IN D

–

V +IN C

–

IN C

8

OUT C

04356-0-044

14

OUT D

13

–IN D

12

+IN D

11

V–

10

+IN C

9

–IN C

8

OUT C

04356-0-046

Rev. A

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.

AD8603/AD8607/AD8609

TABLE OF CONTENTS

Specifications..................................................................................... 3

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

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

Applications..................................................................................... 12

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

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

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

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

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

Battery-Powered Applications .................................................. 14

Photodiodes ................................................................................ 14

Outline Dimensions....................................................................... 15

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

REVISION HISTORY

10/03—Data Sheet Changed from Rev. 0 to Rev. A

Change Page

Added AD8607 and AD8609 parts ..............................Universal

Changes to Specifications............................................................ 3

Changes to Figure 35.................................................................. 10

Added Figure 41.......................................................................... 11

Rev. A | Page 2 of 16

AD8603/AD8607/AD8609

SPECIFICATIONS

Table 1. Electrical Characteristics @ VS = 5 V, VCM = VS/2, TA = 25°C, unless otherwise noted

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

Output Current I

Closed-Loop Output Impedance Z

±80 mA

OUT

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/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. A | Page 3 of 16

AD8603/AD8607/AD8609

Table 2. Electrical Characteristics @ VS = 1.8 V, VCM = VS/2, TA = 25°C, unless otherwise noted

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

Output Current I

Closed-Loop Output Impedance Z

±7 mA

OUT

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/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

= 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

Channel Separation Cs f = 10 kHz –115 dB

f = 100 kHz –110 dB

Rev. A | Page 4 of 16

AD8603/AD8607/AD8609

ABSOLUTE MAXIMUM RATINGS

Table 3. AD8603/AD8607/AD8609 Stress Ratings

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

All Packages –65°C to +150°C Lead Temperature Range (Soldering, 60 Sec) 300°C Operating Temperature Range –40°C to +125°C Junction Temperature Range

All Packages –65°C to +150°C

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although these parts feature proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

1, 2

Table 4. Package Characteristics

Package Type θ

5-Lead TSOT-23 (UJ) 207 61 °C/W 8-Lead MSOP (RM) 210 45 °C/W 8-Lead SOIC (R) 158 43 °C/W 14-Lead SOIC (R) 120 36 °C/W 14-Lead TSSOP (RU) 180 35 °C/W

1

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 listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

2

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

3

θJA is specified for the worst-case conditions, i.e., θJA is specified for device

soldered in circuit board for surface-mount packages.

3

θJC Unit

JA

Rev. A | Page 5 of 16

AD8603/AD8607/AD8609

TYPICAL PERFORMANCE CHARACTERISTICS

2600

VS = 5V

2400

TA = 25°C

2200

VCM = 0V to 5V

2000

1800

1600

1400

1200

1000

800

600

NUMBER OF AMPLIFIERS

400

200

0

–270

–210

–150 –30 30 90 210 270–90

VOS (µV)

Figure 6. Input Offset Voltage Distribution

30

0 150

04356-0-002

300

VS = 3.3V

250

TA = 25°C

200

150

100

50

0

(µV)

OS

–50

V

–100

–150

–200

–250

–300

0.0

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

04356-0-005

3.3

NUMBERS OF AMPLIFIERS

25

20

15

10

5

0

0.4 0.8 1.2 2.0 2.4 2.8 3.6 4.0 4.4 4.8

1.6 3.2 TCVOS (µV/°C)

VS= ±2.5V

= –40°C TO +125°C

T

A

= 0V

V

CM

Figure 7. Input Offset Voltage Drift Distribution

300

VS = 5V

250

TA = 25°C

200

150

100

50

0

(µV)

OS

–50

V

–100

–150

–200

–250

–300

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

04356-0-003

04356-0-004

350

300

250

200

150

100

INPUT BIAS CURRENT (pA)

VS= ±2.5V

50

0

25

50 100 125

TEMPERATURE (°C)

75

Figure 10. Input Bias vs. Temperature

1000

VS= 5V

= 25°C

T

100

10

1

0.1

OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

0.01

0.001

A

SOURCE

0.01 0.1 1 LOAD CURRENT (mA)

SINK

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

04356-0-006

04356-0-007

10

Rev. A | Page 6 of 16

AD8603/AD8607/AD8609

350

= 5V

V

S

= 25°C

T

A

300

DD–VOH

V

@ 10mA LOAD

OL

V

DD–VOH

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

@ 1mA LOAD

VOL@ 1mA LOAD

250

200

150

100

OUTPUT SWING (mV)

V

50

0

–25 –10 125

–40

Figure 12. Output Voltage Swing vs. Temperature

100

VS= ±2.5V

80

RL= 100kΩ CL= 20pF φ = 70.9°

60

40

20

0

–20

–40

OPEN-LOOP GAIN (dB)

–60

–80

–100

1k 10k 100k 1M 10M

FREQUENCY (Hz)

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

5.0

VS= 5V

4.5 VIN= 4.9V p-p

T = 25°C

4.0 A

= 1

V

3.5

3.0

2.5

2.0

1.5

OUTPUT SWING (V p-p)

1.0

0.5

0.0

0.01

0.1 1 100 FREQUENCY (kHz)

10

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

225

180

135

90

45

0

–45

–90

–135

–180

–225

04356-0-008

PHASE (Degree)

04356-0-010

04356-0-011

1925

OUTPUT IMPEDANCE (Ω)

1750

1575

1400

1225

1050

875

700

525

350

175

100

VS= ±2.5V, ±0.9V

A = 100

A = 10

1k 100k

10k

FREQUENCY (Hz)

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. Common-Mode Rejection Ratio vs. Frequency

140

VS= ±2.5V

120

100

80

60

40

20

PSRR (dB)

0

–20

–40

–60

10 100 1k 10k 100k

FREQUENCY (Hz)

Figure 17. PSRR v s. Frequency

A = 1

04356-0-012

VS = ±2.5V

04356-0-013

100k

04356-0-014

Rev. A | Page 7 of 16

AD8603/AD8607/AD8609

60

VS= 5V

50

40

30

20

10

SMALL SIGNAL OVERSHOOT (%)

OS–

OS+

VS = 5V, 1.8V

VOLTAGE NOISE (1µV/DIV)

0

10

LOAD CAPACITANCE (pF)

100 1000

Figure 18. Small Signal Overshoot vs. Load Capacitance

60

55

VS= ±2.5V

50

45

40

35

30

25

20

SUPPLY CURRENT (µA)

15

10

5

0 –40

–10 5 35 65

20 80–25 50

TEMPERATURE (°C)

Figure 19. Supply Current vs. Temperature

100

90

80

70

60

50

40

30

SUPPLY CURRENT (µA)

20

10

0

1.0

2.0 4.0 5.0

SUPPLY VOLTAGE (V)

TA= 25°C

3.0

Figure 20. Supply Current vs. Supply Voltage

95 110 125

04356-0-015

04356-0-016

04356-0-017

TIME (1s/DIV)

Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise

VS = 5V RL = 10k

Ω

CL = 200pF AV = 1

VOLTAGE (50mV/DIV)

TIME (4

Figure 22. Small Signal Transient

VS = 5V RL = 10k

Ω

CL = 200pF

= 1

A

V

VOLTAGE (1V/DIV)

TIME (20µs/DIV)

Figure 23. Large Signal Transient

µ

s/DIV)

04356-0-018

04356-0-019

04356-0-020

Rev. A | Page 8 of 16

AD8603/AD8607/AD8609

VS= ±2.5V

= 10kΩ

R

L

= 100

A

+2.5V

0V

VOLTAGE (50mV/DIV)

–50mV

V

IN

= 50mV

TIME (4µs/DIV))

TIME (40µs/DIV))

Figure 24. Negative Overload Recovery

VS = ±2.5V

= 10kΩ

R

L

= 100

A

V

= 50mV

V

IN

0V

VOLTAGE (50mV/DIV)

–50mV

TIME (4µs/DIV)

Figure 25. Positive Overload Recovery

168

144

120

96

72

48

24

VOLTAGE NOISE DENSITY (nV/ Hz)

0

0.1 1.00.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90

FREQUENCY (kHz)

Figure 26. Voltage Noise Density vs. Frequency

04356-0-021

+2.5V

04356-0-022

VS = ±2.5V

04356-0-045

176

154

132

110

88

66

44

22

VOLTAGE NOISE DENSITY (nV/ Hz)

0

110234567890

FREQUENCY (kHz)

VS = ±2.5V

Figure 27. Voltage Noise Density vs. Frequency

800

NUMBER OF AMPLIFIERS

750

700 650

600

550

500

450 400

350 300

250

200

150

100

50

0

–300

–240 60 240–180 –120 120 180 300

Figure 28. V

0–60

VOS (µV)

Distribution

OS

VS = 1.8V

= 25°C

T

A

= 0V to 1.8V

V

CM

300

VS = 1.8V

250

200

150

100

(µV)

OS

–50

V

–100

–150

–200

–250

–300

= 25°C

T

A

50

0

0.0

0.9

0.60.3 1.5 1.81.2

VCM(V)

VCM (V)

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

04356-0-046

04356-0-025

04356-0-026

Rev. A | Page 9 of 16

AD8603/AD8607/AD8609

1000

VS= 1.8V

= 25°C

T

A

100

10

1

0.1

OUTPUT VOLTAGE TO SUPPLY RAIL (mV)

0.01

0.001

SOURCE

SINK

0.01 0.1 1 LOAD CURRENT (mA)

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

10

04356-0-027

100

VS= ±0.9V RL= 100kΩ

80

CL= 20pF φ = 70°

60

40

20

0

–20

–40

OPEN-LOOP GAIN (dB)

–60

–80

–100

1 10 100 1M 10M

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

100

90

80

70

60

50

40

30

OUTPUT SWING (mV)

20

10

0

–40

–25

VS = 1.8V

VDD– VOH@ 1mA LOAD

VOL@ 1mA LOAD

–10

5 35 125

20

TEMPERATURE (°C)

50 65 80 95 110

04356-0-028

140

120

VS= 1.8V

100

80

60

40

20

CMRR (dB)

0

–20

–40

–60

100 1k 10k 100k

FREQUENCY (Hz)

225

180

135

90

45

0

–45

–90

–135

–180

–225

PHASE (Degree)

04356-0-030

04356-0-031

Figure 31. Output Voltage Swing vs. Temperature

60

VS = 1.8V

= 25°C

T

A

50

40

30

20

10

SMALL SIGNAL OVERSHOOT (%)

= 1

A

V

OS–

0

10

LOAD CAPACITANCE (pF)

100 1000

Figure 32. Small Signal Overshoot vs. Load Capacitance

OS+

04356-0-029

Rev. A | Page 10 of 16

Figure 34. Common-Mode Rejection Ratio vs. Frequency

1.8

VS= 1.8V VIN= 1.7V p–p

1.5 T= 25°C

)

P-P

OUTPUT SWING (V

AV= 1

1.2

0.9

0.6

0.3

0.0

0.01 0.1 1 10010 FREQUENCY (kHz)

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

04356-0-032

AD8603/AD8607/AD8609

VS = 1.8V

= 10kΩ

R

L

= 200pF

C

L

= 1

A

V

VOLTAGE (50mV/DIV)

Figure 36. Small Signal Transient

VS= 1.8V RL= 10kΩ

= 200pF

C

L

= 1

A

V

TIME (4µs/DIV)

04356-0-033

–20

–40

–60

176

154

132

110

88

66

44

22

VOLTAGE NOISE DENSITY (nV/ Hz)

0

110234567890

FREQUENCY (kHz)

VS = ±0.9V

04356-0-048

Figure 39. Voltage Noise Density

0

VS = ±2.5V, ±0.9V

–80

VOLTAGE (500mV/DIV)

04356-0-034

TIME (20µs/DIV)

Figure 37. Large Signal Transient

168

140

112

84

56

28

VOLTAGE NOISE DENSITY (nV/ Hz)

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

04356-0-047

–100

CHANNEL SEPARATION (dB)

–120

–140

100

1k 10k 100k

Figure 40. Channel Separation

FREQUENCY (Hz)

04356-A-043

1M

Figure 38. Voltage Noise Density

Rev. A | 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 V

V

IN

V

OUT

IN

A

V

R

L

= 6V p-p = 1 = 10kΩ

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

VOLTAGE (1V/DIV)

04356-0-037

TIME (4µs/DIV)

Figure 41. No Phase Response

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 equation

– VS)/(RS + 200 Ω) ≤ 5 mA

(V

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.

04356-0-038

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

V

EE

–

V V+

R

S

200mV

+ –

150Ω

V

CC

C

S

47pF

C

L

04356-A-039

Figure 43. Snubber Network

VSY = ±0.9V V

= 100mV

IN

C

= 2nF

L

R

= 10kΩ

L

R

= 150Ω

S

C

= 470pF

S

04356-0-040

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

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

Table 5. Optimum Values for the Snubber Network

CL (pF) RS (Ω) CS (pF)

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

Rev. A | 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 the feedback in parallel with R2 (Figure 45) improves the phase margin. Picking C

= 50 pF yields a phase margin of

F

about 45° for the values shown in Figure 45.

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 since they are divided by the high gain of the AD8603.

,

F

R1

1kΩ

V

IN

R2

99kΩ

V

EE

V

CC

V

–

AD8603

V+

V

CC

R3 R4

U5

V+

AD8541

V

–

V

EE

99kΩ1kΩ

04356-A-041

Figure 45. High Gain Composite Amplifier

R2

100kΩ

V

AD8603

R1

1kΩ

V

IN

EE

R3

–

V V+

1kΩ

C2

V

CC

V

CC

R4

V+ V

–

100Ω

AD8541

V

C3

EE

04356-A-042

Figure 46. Low Power Composite Amplifier

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

Rev. A | Page 13 of 16

AD8603/AD8607/AD8609

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 bar code 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.

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

CC

1000MΩ

10pF

R1

C1

AD8603

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

V

EE

Figure 47. Photodiode Circuit

04356-0-044

Rev. A | Page 14 of 16

AD8603/AD8607/AD8609

Y

OUTLINE DIMENSIONS

5.00 (0.1968)

4.80 (0.1890)

4.00 (0.1574)

3.80 (0.1497)

85

6.20 (0.2440)

5.80 (0.2284)

41

1.27 (0.0500) BSC

0.25 (0.0098)

0.10 (0.0040)

COPLANARIT

0.10

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

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012AA

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°

1.27 (0.0500)

0°

0.40 (0.0157)

× 45°

Figure 48. 8-Lead Standard Small Outline Package (SOIC) [R-8]

Dimensions shown in millimeters and (inches)

2.90 BSC

45

0.50

0.30

2.80 BSC

0.95 BSC

1.00 MAX

SEATING PLANE

0.20

0.08

8° 4°

0.60

0.45

0.30

1.60 BSC

0.90

0.87

0.84

0.10 MAX

13

2

PIN 1

1.90 BSC

COMPLIANT TO JEDEC STANDARDS MO-193AB

Figure 49. 5-Lead Thin Small Outline Transistor Package [TSOT ]

(UJ-5)

Dimensions in millimeters

3.00

BSC

85

3.00

BSC

PIN 1

0.65 BSC

0.15

0.00

0.38

0.22

COPLANARITY

0.10

COMPLIANT TO JEDEC STANDARDS MO-187AA

4.90 BSC

4

SEATING PLANE

1.10 MAX

0.23

0.08

8° 0°

0.80

0.60

0.40

Figure 50. 8-Lead MSOP Package (RM-8)

Dimensions in millimeters

Rev. A | Page 15 of 16

AD8603/AD8607/AD8609

8.75 (0.3445)

8.55 (0.3366)

4.00 (0.1575)

3.80 (0.1496)

0.25 (0.0098)

0.10 (0.0039)

COPLANARITY

0.10

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

14

1

1.27 (0.0500) BSC

0.51 (0.0201)

0.31 (0.0122)

COMPLIANT TO JEDEC STANDARDS MS-012AB

8

6.20 (0.2441)

7

5.80 (0.2283)

1.75 (0.0689)

1.35 (0.0531)

SEATING PLANE

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0197)

0.25 (0.0098)

8°

 

0°

1.27 (0.0500)

0.40 (0.0157)

× 45°



Figure 51. 14-Lead Standard Small Outline Package (SOIC) [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-153AB-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

ORDERING GUIDE

Model Temperature Range Package Description Package Option Branding

AD8603AUJ-R2 –40°C to +125°C 5-Lead TSOT-23 UJ-5 BFA AD8603AUJ-REEL –40°C to +125°C 5-Lead TSOT-23 UJ-5 BFA AD8603AUJ-REEL7 –40°C to +125°C 5-Lead TSOT-23 UJ-5 BFA 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 AD8607AR –40°C to +125°C 8-Lead SOIC R-8 AD8607AR-REEL –40°C to +125°C 8-Lead SOIC R-8 AD8607AR-REEL7 –40°C to +125°C 8-Lead SOIC R-8 AD8609AR –40°C to +125°C 14-Lead SOIC R-14 AD8609AR-REEL –40°C to +125°C 14-Lead SOIC R-14 AD8609AR-REEL7 –40°C to +125°C 14-Lead SOIC R-14 AD8609ARU –40°C to +125°C 14-Lead TSSOP RU-14 AR8609ARU-REEL –40°C to +125°C 14-Lead TSSOP RU-14

C04356–0–10/03(A)

Rev. A | Page 16 of 16

Datasheet AD8603 Datasheet (Analog Devices)

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

PIN CONFIGURATIONS

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

TYPICAL PERFORMANCE CHARACTERISTICS

APPLICATIONS

NO PHASE REVERSAL

INPUT OVERVOLTAGE PROTECTION

DRIVING CAPACITIVE LOADS

PROXIMITY SENSORS

COMPOSITE AMPLIFIERS

BATTERY-POWERED APPLICATIONS

PHOTODIODES

OUTLINE DIMENSIONS

ORDERING GUIDE