Low Cost Instrumentation Amplifier

AD622

Rev. D

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FEATURES

Easy to use

Low cost solution

Higher performance than two or three op amp design

Unity gain with no external resistor

Optional gains with one external resistor

(Gain range: 2 to 1000)

Wide power supply range: ±2.6 V to ±15 V

Available in 8-lead PDIP and 8-lead SOIC_N packages

Low power, 1.5 mA maximum supply current

DC performance

0.15% gain accuracy: G = 1

125 μV maximum input offset voltage

1.0 μV/°C maximum input offset drift

5 nA maximum input bias current

66 dB minimum common-mode rejection ratio: G = 1

Noise

12 nV/√Hz @ 1 kHz input voltage noise

0.60 μV p-p noise: 0.1 Hz to 10 Hz, G = 10

AC characteristics

800 kHz bandwidth: G = 10

10 μs settling time to 0.1% @ G = 1 to 100

1.2 V/μs slew rate

APPLICATIONS

Transducer interface

Low cost thermocouple amplifier

Industrial process controls

Difference amplifier

Low cost data acquisition

PIN CONFIGURATION

8

7

OUTPUT

6

REF

5

AD622

Figure 1. 8-Lead PDIP and 8-Lead SOIC_N

(N and R Suffixes)

GENERAL DESCRIPTION

The AD622 is a low cost, moderately accurate instrumentation

amplifier that requires only one external resistor to set any gain

between 2 and 1000. For a gain of 1, no external resistor is

required. The AD622 is a complete difference or subtracter

amplifier system that also provides superior linearity and

common-mode rejection by incorporating precision laser-

trimmed resistors.

The AD622 replaces low cost, discrete, two or three op amp

instrumentation amplifier designs and offers good common-

mode rejection, superior linearity, temperature stability,

reliability, and board area consumption. The low cost of the

AD622 eliminates the need to design discrete instrumentation

amplifiers to meet stringent cost targets. While providing a

lower cost solution, it also provides performance and space

improvements.