Precision, Dual-Channel

Instrumentation Amplifier

AD8222

Rev. 0

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FEATURES

Two channels in small 4 mm × 4 mm LFCSP

Gain set with 1 resistor per amplifier (G = 1 to 10,000)

Low noise

8 nV/√Hz @ 1 kHz

0.25 μV p-p (0.1 Hz to 10 Hz)

High accuracy dc performance (B grade)

60 μV maximum input offset voltage

0.3 μV/°C maximum input offset drift

1.0 nA maximum input bias current

126 dB minimum CMRR (G = 100)

Excellent ac performance

150 kHz bandwidth (G = 100)

13 μs settling time to 0.001%

Differential output option (single channel)

Fully specified

Adjustable common-mode output

Supply range: ±2.3 V to ±18 V

APPLICATIONS

Multichannel data acquisition for

ECG and medical instrumentation

Industrial process controls

Wheatstone bridge sensors

Differential drives for

High resolution input ADCs

Remote sensors

FUNCTIONAL BLOCK DIAGRAM

AD8222

1

2

3

4

12

11

10

9

56

7

8

13

14

15

16

–IN1

RG1

RG1

+IN1

–IN2

RG2

RG2

+IN2

Figure 1. 4mm × 4 mm LFCSP

Table 1. In Amps and Differential Amplifier by Category

High

Performance

Low

Cost

High

Voltage

Mil

Grade

Low

Power

Digital

Prog

Gain

AD8221

AD82201

AD8222

AD85531

AD6231

AD628

AD629

AD620

AD621

AD524

AD526

AD624

AD6271

AD85551

AD85561

AD85571

GENERAL DESCRIPTION

The AD8222 is a dual-channel, high performance instrumentation

amplifier that requires only one external resistor per amplifier

to set gains of 1 to 10,000.

The AD8222 is the first dual-instrumentation amplifier in the

small 4 mm × 4mm LFCSP. It requires the same board area as a

typical single instrumentation amplifier. The smaller package

allows a 2× increase in channel density and a lower cost per

channel, all with no compromise in performance.

The AD8222 can also be configured as a single-channel,

differential output instrumentation amplifier. Differential

outputs provide high noise immunity, which can be useful when

the output signal must travel through a noisy environment, such

as with remote sensors. The configuration can also be used to

drive differential input ADCs.

The AD8222 maintains a minimum CMRR of 80 dB to 4 kHz

for all grades at G = 1. High CMRR over frequency allows the

AD8222 to reject wideband interference and line harmonics,

greatly simplifying filter requirements. The AD8222 also has a

typical CMRR drift over temperature of just 0.07 μV/V/°C at G = 1.

The AD8222 operates on both single and dual supplies and only

requires 2.2 mA maximum supply current for both amplifiers. It

is specified over the industrial temperature range of −40°C to

+85°C and is fully RoHS compliant.

For a single-channel version, see the AD8221.