AD8221 is a precision instrumentation amplifier with features such as easy to use, wide power supply range, excellent AC and DC performance, low noise, etc. It is suitable for applications such as weigh scales, industrial process controls, bridge amplifiers, precision data acquisition systems, medical instrumentation, strain gages, and transducer interfaces.
The AD8221 is a gain‑programmable, high‑performance instrumentation amplifier that offers the industry’s highest CMRR over frequency in its class. It provides a gain range of 1 to 1000 set by a single external resistor and operates from a wide supply voltage of +2.3 V to +18 V, making it suitable for space‑constrained, multichannel designs.
Key features include an 80 dB minimum CMRR at 1 kHz (G=1), 825 kHz –3 dB bandwidth at unity gain, low input noise of 8 nV/√Hz at 1 kHz, and operation over an industrial temperature range of –40 °C to +85 °C (extended to +125 °C for specified performance). The device is available in 8‑lead SOIC and MSOP packages.
| Gain range | 1 to 1000 (set by a single external resistor) |
|---|---|
| Supply voltage range | +2.3 V to +18 V |
| CMRR (G=1) at 1 kHz | 80 dB minimum |
| Input voltage noise (1 kHz) | 8 nV/√Hz |
| Small‑signal bandwidth (G=1) | 825 kHz |
| Quiescent current | 0.9 mA typical |
| Operating temperature range | –40 °C to +85 °C (specified), –40 °C to +125 °C (extended) |
The AD8221 provides a programmable gain from 1 to 1000 set by a single external resistor.
The device operates with a supply voltage from +2.3 V up to +18 V.
It achieves a minimum of 80 dB CMRR at 1 kHz when the gain is set to 1.
The input voltage noise is 8 nV/√Hz at 1 kHz.