ANALOG DEVICES AD627 Service Manual

Micropower, Single- and Dual-Supply,

–V

www.BDTIC.com/ADI

Rail-to-Rail Instrumentation Amplifier

FEATURES

Micropower, 85 µA maximum supply current Wide power supply range (+2.2 V to ±18 V) Easy to use

Gain set with one external resistor

Gain range 5 (no resistor) to 1000 Higher performance than discrete designs Rail-to-rail output swing High accuracy dc performance

0.03% typical gain accuracy (G = +5) (AD627A)

10 ppm/°C typical gain drift (G = +5)

125 µV maximum input offset voltage (AD627B dual supply)

200 µV maximum input offset voltage (AD627A dual supply)

1 µV/°C maximum input offset voltage drift (AD627B)

3 µV/°C maximum input offset voltage drift (AD627A)

10 nA maximum input bias current Noise: 38 nV/√Hz RTI noise @ 1 kHz (G = +100) Excellent ac specifications

AD627A: 77 dB minimum CMRR (G = +5)

AD627B: 83 dB minimum CMRR (G = +5)

80 kHz bandwidth (G = +5)

135 µs settling time to 0.01% (G = +5, 5 V step)

APPLICATIONS

4 to 20 mA loop-powered applications Low power medical instrumentation—ECG, EEG Transducer interfacing Thermocouple amplifiers Industrial process controls Low power data acquisition Portable battery-powered instruments

GENERAL DESCRIPTION

The AD627 is an integrated, micropower instrumentation amplifier that delivers rail-to-rail output swing on single and dual (+2.2 V to ±18 V) supplies. The AD627 provides excellent ac and dc specifications while operating at only 85 µA maximum.

The AD627 offers superior flexibility by allowing the user to set t

he gain of the device with a single external resistor while conforming to the 8-lead industry-standard pinout configuration. With no external resistor, the AD627 is configured for a gain of 5. With an external resistor, it can be set to a gain of up to 1000.

A wide supply voltage range (+2.2 V to ±18 V) and micropower

urrent consumption make the AD627 a perfect fit for a wide

c range of applications. Single-supply operation, low power consumption, and rail-to-rail output swing make the AD627

Rev. D

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her 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.

AD627

FUNCTIONAL BLOCK DIAGRAM

R

G

–IN

+IN

S

Figure 1. 8-Lead PDIP (N) and SOIC_N (R)

100

90

80

70

60

50

40

CMRR (dB)

30

20

10

0

1 10 100

DISCRETE DESI GN

Figure 2. CMRR vs. Frequency, ±5 V

ideal for battery-powered applications. Its rail-to-rail output stage maximizes dynamic range when operating from low supply voltages. Dual-supply operation (±15 V) and low power consumption make the AD627 ideal for industrial applications, including 4 to 20 mA loop-powered systems.

The AD627 does not compromise performance, unlike other

opower instrumentation amplifiers. Low voltage offset,

micr offset drift, gain error, and gain drift minimize errors in the system. The AD627 also minimizes errors over frequency by providing excellent CMRR over frequency. Because the CMRR remains high up to 200 Hz, line noise and line harmonics are rejected.

The AD627 provides superior performance, uses less circuit

oard area, and costs less than micropower discrete designs.

b

AD627

1

2

3

4

TRADITIONAL

LOW POWER

FREQUENCY ( Hz)

R

8

G

+V

7

S

OUTPUT

6

REF

5

1k 10k

, Gain = +5

S

AD627

00782-001

00782-002

AD627

www.BDTIC.com/ADI

REVISION HISTORY

11/07—Rev. C to Rev. D

Changes to Features.......................................................................... 1

Changes to Figure 29 to Figure 34 Captions............................... 13

Changes to Setting the Gain Section............................................ 15

Changes to Input Range Limitations in Single-Supply

Applications Section....................................................................... 16

Changes to Table 7.......................................................................... 17

Changes to Figure 41...................................................................... 18

11/05—Rev. B to Rev. C

pdated Format..................................................................Universal

U Added Pin Configurations and Function

Descriptions Section ........................................................................ 8

Change to Figure 33 ....................................................................... 13

Updated Outline Dimensions....................................................... 24

Changes to Ordering Guide.......................................................... 24

Rev. A to Rev. B

hanges to Figure 4 and Table I, Resulting Gain column......... 11

C

Change to Figure 9 ......................................................................... 13

Rev. D | Page 2 of 24

AD627

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SPECIFICATIONS

SINGLE SUPPLY

Typical @ 25°C single supply, VS = 3 V and 5 V, and RL = 20 kΩ, unless otherwise noted.

Table 1.

AD627A AD627B Parameter Conditions Min Typ Max Min Typ Max Unit

GAIN G = +5 + (200 kΩ/RG)

Gain Range 5 1000 5 1000 V/V Gain Error

Nonlinearity

Gain vs. Temperature

VOLTAGE OFFSET

Input Offset, V

Output Offset, V

Offset Referred to the

INPUT CURRENT

Input Bias Current 3 10 3 10 nA

Input Offset Current 0.3 1 0.3 1 nA

INPUT

Input Impedance

Common-Mode Rejection

OUTPUT

Output Swing RL = 20 kΩ (−VS) + 25 (+VS) − 70 (−VS) + 25 (+VS) − 70 mV R Short-Circuit Current Short circuit to ground ±25 ±25 mA

1

G = +5 0.03 0.10 0.01 0.06 % G = +10 0.15 0.35 0.10 0.25 % G = +100 0.15 0.35 0.10 0.25 % G = +1000 0.50 0.70 0.25 0.35 %

G = +5 10 100 10 100 ppm G = +100 20 100 20 100 ppm

G = +5 10 20 10 20 ppm/°C G > +5 −75 −75 ppm/°C

2

OSI

Over Temperature VCM = V Average TC 0.1 3 0.1 1 µV/°C

1000 500 µV

OSO

Over Temperature 1650 1150 µV Average TC 2.5 10 2.5 10 µV/°C

Input vs. Supply (PSRR) G = +5 86 100 86 100 dB G = +10 100 120 100 120 dB G = +100 110 125 110 125 dB G = +1000 110 125 110 125 dB

Over Temperature 15 15 nA Average TC 20 20 pA/°C

Over Temperature 2 2 nA Average TC 1 1 pA/°C

Differential 20||2 20||2 GΩ||pF Common-Mode 20||2 20||2 GΩ||pF Input Voltage Range3VS = 2.2 V to 36 V (−VS) − 0.1 (+VS) − 1 (−VS) − 0.1 (+VS) – 1 V

3

Ratio

DC to 60 Hz with

1 kΩ Source Imbalance G = +5 VS = 3 V, VCM = 0 V to 1.9 V 77 90 83 96 dB G = +5 VS = 5 V, VCM = 0 V to 3.7 V 77 90 83 96 dB

V

= (−VS) + 0.1 to (+VS) − 0.15

OUT

1

50 250 25 150 µV

= +VS/2 445 215 µV

REF

= VS/2

V

REF

= 100 kΩ (−VS) + 7 (+VS) − 25 (−VS) + 7 (+VS) − 25 mV

L

Rev. D | Page 3 of 24

AD627

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AD627A AD627B Parameter Conditions Min Typ Max Min Typ Max Unit

DYNAMIC RESPONSE

Small Signal −3 dB

Bandwidth G = +5 80 80 kHz G = +100 3 3 kHz

G = +1000 0.4 0.4 kHz Slew Rate +0.05/−0.07 +0.05/−0.07 V/µs Settling Time to 0.01% VS = 3 V, 1.5 V output step

G = +5 65 65 µs G = +100 290 290 µs

Settling Time to 0.01% VS = 5 V, 2.5 V output step

G = +5 85 85 µs G = +100 330 330 µs

Overload Recovery 50% input overload 3 3 µs

1

Does not include effects of External Resistor RG.

2

See Table 8 for total RTI errors.

3

See the Using the AD627 section for more information on the input range, gain range, and common-mode range.

Rev. D | Page 4 of 24

AD627

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DUAL SUPPLY

Typical @ 25°C dual supply, VS = ±5 V and ±15 V, and RL = 20 kΩ, unless otherwise noted.

Table 2.

Parameter Conditions Min Typ Max Min Typ Max Unit

GAIN G = +5 + (200 kΩ/RG)

Gain Range 5 1000 5 1000 V/V Gain Error1 V

G = +5 0.03 0.10 0.01 0.06 % G = +10 0.15 0.35 0.10 0.25 % G = +100 0.15 0.35 0.10 0.25 % G = +1000 0.50 0.70 0.25 0.35 %

Nonlinearity

G = +5 VS = ±5 V/±15 V 10/25 100 10/25 100 ppm G = +100 VS = ±5 V/±15 V 10/15 100 10/15 100 ppm

Gain vs. Temperature1

G = +5 10 20 10 20 ppm/°C G > +5 –75 −75 ppm/°C

VOLTAGE OFFSET Total RTI error =

Input Offset, V

Over Temperature VCM = V Average TC 0.1 3 0.1 1 µV/°C

Output Offset, V

Over Temperature 1700 1100 µV Average TC 2.5 10 2.5 10 µV/°C

Offset Referred to the Input

vs. Supply (PSRR) G = +5 86 100 86 100 dB G = +10 100 120 100 120 dB G = +100 110 125 110 125 dB G = +1000 110 125 110 125 dB

INPUT CURRENT

Input Bias Current 2 10 2 10 nA

Over Temperature 15 15 nA Average TC 20 20 pA/°C

Input Offset Current 0.3 1 0.3 1 nA

Over Temperature 5 5 nA Average TC 5 5 pA/°C

INPUT

Input Impedance

Differential 20||2 20||2 GΩ||pF Common Mode 20||2 20||2 GΩ||pF Input Voltage Range3 VS = ±1.1 V to ±18 V (−VS) − 0.1 (+VS) − 1 (−VS) − 0.1 (+VS) − 1 V

Common-Mode Rejection

3

Ratio 1 kΩ Source Imbalance

G = +5 to +1000 VS = ±5 V, VCM =

G = +5 to +1000 VS = ±15 V, VCM =

OUTPUT

Output Swing RL = 20 kΩ (−VS) + 25 (+VS) − 70 (−VS) + 25 (+VS) − 70 mV R Short-Circuit Current Short circuit to ground ±25 ±25 mA

2

25 200 25 125 µV

OSI

1000 500 µV

OSO

DC to 60 Hz with

= (−VS) + 0.1 to

OUT

) − 0.15

(+V

S

+ V

V

OSI

−4 V to +3.0 V

−12 V to +10.9 V

L

/G

OSO

= 0 V 395 190 µV

REF

= 100 kΩ (−VS) + 7 (+VS) − 25 (−VS) + 7 (+VS) − 25 mV

77 90 83 96 dB

AD627A AD627B

Rev. D | Page 5 of 24

AD627

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Parameter Conditions Min Typ Max Min Typ Max Unit

DYNAMIC RESPONSE

Small Signal −3 dB

Bandwidth

G = +5 80 80 kHz

G = +100 3 3 kHz

G = +1000 0.4 0.4 kHz Slew Rate +0.05/−0.06 +0.05/−0.06 V/µs Settling Time to 0.01% VS = ±5 V,

G = +5 135 135 µs

G = +100 350 350 µs Settling Time to 0.01% VS = ±15 V,

G = +5 330 330 µs

G = +100 560 560 µs Overload Recovery 50% input overload 3 3 µs

1

Does not include effects of External Resistor RG.

2

See Table 8 for total RTI errors.

3

See the Using the AD627 section for more information on the input range, gain range, and common-mode range.

+5 V output step

+15 V output step

DUAL AND SINGLE SUPPLIES

AD627A AD627B

Table 3.

Parameter Conditions Min Typ Max Min Typ Max Unit

NOISE

Voltage Noise, 1 kHz

Input, Voltage Noise, eni 38 38 nV/√Hz Output, Voltage Noise, eno 177 177 nV/√Hz RTI, 0.1 Hz to 10 Hz

G = +5 1.2 1.2 µV p-p

G = +1000 0.56 0.56 µV p-p Current Noise f = 1 kHz 50 50 fA/√Hz

0.1 Hz to 10 Hz 1.0 1.0 pA p-p

REFERENCE INPUT

RIN R Gain to Output 1 1 Voltage Range1

POWER SUPPLY

Operating Range Dual supply ±1.1 ±18 ±1.1 ±18 V Single supply 2.2 36 2.2 36 V Quiescent Current 60 85 60 85 µA Over Temperature 200 200 nA/°C

TEMPERATURE RANGE

For Specified Performance −40 +85 −40 +85 °C

1

See Using the AD627 section for more information on the reference terminal, input range, gain range, and common-mode range.

= ∞ 125 125 kΩ

G

() ( )

/

ReeNoiseRTITotal +=

Gnoni

22

AD627A AD627B

Rev. D | Page 6 of 24

AD627

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ABSOLUTE MAXIMUM RATINGS

Table 4.

Parameter Rating

Supply Voltage ±18 V Internal Power Dissipation

PDIP (N-8) 1.3 W SOIC_N (R-8) 0.8 W

−IN, +IN −VS − 20 V to +VS + 20 V Common-Mode Input Voltage −VS − 20 V to +VS + 20 V Differential Input Voltage (+IN − (−IN)) +VS − (−VS) Output Short-Circuit Duration Indefinite Storage Temperature Range (N, R) −65°C to +125°C Operating Temperature Range −40°C to +85°C Lead Temperature (Soldering, 10 sec) 300°C

1

Specification is for device in free air:

8-lead PDIP package: θJA = 90°C/W. 8-lead SOIC_N package: θJA = 155°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 indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ESD CAUTION

Rev. D | Page 7 of 24

AD627

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PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

R

1

G

S

AD627

2

TOP VIEW

3

(Not to Scale)

4

–IN

+IN

–V

Figure 3. 8-Lead PDIP Pin Configuration

Table 5. Pin Function Descriptions

Pin No. Mnemonic Description

1 RG External Gain Setting Resistor. Place gain setting resistor across RG pins to set the gain. 2 −IN Negative Input. 3 +IN 4 −V

Negative Voltage Supply Pin.

S

5 REF 6 OUTPUT 7 +V 8 R

Positive Supply Voltage.

S

External Gain Setting Resistor. Place gain setting resistor across RG pins to set the gain.

G

Positive Input.

Reference Pin. Drive with low impedance voltage source to level shift the output voltage. Output Voltage.

R

8

7

+V

6

OUTPUT

REF

5

G

S

0782-051

1

R

G

AD627

2

–IN

TOP VIEW

3

+IN

(Not to Scale)

–V

4

S

Figure 4. 8-Lead SOIC_N Pin

8

R

G

+V

7

S

6

OUTPUT

5

REF

Configuration

00782-052

Rev. D | Page 8 of 24

ANALOG DEVICES AD627 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

FUNCTIONAL BLOCK DIAGRAM

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

SINGLE SUPPLY

DUAL SUPPLY

DUAL AND SINGLE SUPPLIES

ABSOLUTE MAXIMUM RATINGS

ESD CAUTION

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS