GENERAL DESCRIPTION

The AD8221 is a gain programmable, high performance instrumentation amplifier that delivers the industry’s highest CMRR over frequency in its class. The CMRR of instrumentation amplifiers on the market today falls off at 200 Hz. In contrast, the AD8221 maintains a minimum CMRR of 80 dB to 10 kHz for all grades at G = 1. High CMRR over frequency allows the AD8221 to reject wideband interference and line harmonics, greatly simplifying filter requirements. Possible applications include precision data acquisition, biomedical analysis, and aerospace instrumentation.

FEATURES

Easy to use

Available in space-saving MSOP

Gain set with 1 external resistor (gain range 1 to 1000)

Wide power supply range: ±2.3 V to ±18 V

Temperature range for specified performance:

−40°C to +85°C

Operational up to 125°C1

Excellent AC specifications

80 dB minimum CMRR to 10 kHz (G = 1)

825 kHz, –3 dB bandwidth (G = 1)

2 V/µs slew rate

Low noise

8 nV/√Hz, @ 1 kHz, maximum input voltage noise

0.25 µV p-p input noise (0.1 Hz to 10 Hz)

High accuracy dc performance (AD8221BR)

90 dB minimum CMRR (G = 1)

25 µV maximum input offset voltage

0.3 µV/°C maximum input offset drift

0.4 nA maximum input bias current

APPLICATIONS

Weigh scales

Industrial process controls

Bridge amplifiers

Precision data acquisition systems

Medical instrumentation

Strain gages

Transducer interfaces