Analog Devices Inc. AD8221 Precision Instrumentation Amplifier

Analog Devices AD8221 Precision Instrumentation Amplifier is a gain programmable, high-performance instrumentation amplifier that delivers a high Common-Mode Rejection Ratio (CMRR) over frequency. The CMRR of instrumentation amplifiers on the market today falls off at 200Hz. In contrast, the AD8221 maintains a minimum CMRR of 80dB to 10kHz for all grades at G = 1. The 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.

Low voltage offset, low offset drift, low gain drift, high gain accuracy, and high CMRR make this part an excellent choice in applications that demand the best dc performance possible, such as bridge signal conditioning. Programmable gain affords the user design flexibility. A single resistor sets the gain from 1 to 1000. The AD8221 operates on both single and dual supplies and is well suited for applications where ±10V input voltages are encountered.


  • Easy to use
  • Available in space-saving MSOP
  • Gain set with 1 external resistor (gain range 1 to 1000)
  • Wide power supply range: ±2.3V to ±18V
  • Temperature range for specified performance: −40°C to +85°C
  • Operational up to 125°C
  • Excellent AC specifications
    • 80dB minimum CMRR to 10kHz (G = 1)
    • 825kHz, –3dB bandwidth (G = 1)
    • 2V/μs slew rate
  • Low noise
    • 8nV/√Hz, @ 1kHz, maximum input voltage noise
    • 0.25μVp-p input noise (0.1Hz to 10Hz)
  • High accuracy dc performance (AD8221BR)
    • 90dB minimum CMRR (G = 1)
    • 25μV maximum input offset voltage
    • 0.3μV/°C maximum input offset drift
    • 0.4nA maximum input bias current


  • Weigh scales
  • Industrial process controls
  • Bridge amplifiers
  • Precision data acquisition systems
  • Medical instrumentation
  • Strain gages
  • Transducer interfaces

Connection Diagram

Block Diagram - Analog Devices Inc. AD8221 Precision Instrumentation Amplifier
Published: 2019-06-13 | Updated: 2022-03-10