GENERAL DESCRIPTION:

The AD8221 is a gain programmable, high performanceinstrumentation amplifier that delivers the industry’s highestCMRR over frequency in its class. The CMRR of instrumentationamplifiers on the market today falls off at 200 Hz. In contrast,the AD8221 maintains a minimum CMRR of 80 dB to 10 kHzfor all grades at G = 1. High CMRR over frequency allows theAD8221 to reject wideband interference and line harmonics,greatly simplifying filter requirements. Possible applicationsinclude precision data acquisition, biomedical analysis, andaerospace instrumentation.Low voltage offset, low offset drift, low gain drift, high gainaccuracy, and high CMRR make this part an excellent choicein applications that demand the best dc performance possible,such as bridge signal conditioning.Programmable gain affords the user design flexibility. A singleresistor sets the gain from 1 to 1000. The AD8221 operates onboth single and dual supplies and is well suited for applicationswhere ±10 V input voltages are encountered.The AD8221 is available in a low cost 8-lead SOIC and 8-leadMSOP, both of which offer the industry’s best performance. TheMSOP requires half the board space of the SOIC, making it idealfor multichannel or space-constrained applications.Performance is specified over the entire industrial temperaturerange of −40°C to +85°C for all grades. Furthermore, the AD8221is operational from −40°C to +125°C1. 

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 rateLow 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