Analog Devices AD8422 instrumentation amplifier

The AD8422 from Analog Devices, a high-precision, low-power, low-noise, rail-to-rail instrumentation amplifier with ultralow distortion processes signals with ultralow distortion performance, load independent over its full output range. Very-low bias current is said to make the amplifier error-free with high source impedance, allowing multiple sensors to be multiplexed to the inputs. Low-voltage noise and low-current noise make the device a suitable choice for measuring a Wheatstone bridge.

The device uses robust input protection that ensures reliability without sacrificing noise performance. The device has high ESD immunity, and the inputs are protected from continuous voltages up to 40 V from the opposite supply rail. A single resistor sets the gain from 1 to 1000.

The reference pin can be used to apply a precise offset to the output voltage. The amplifier is specified from -40 to +85°C and has typical performance curves to 125°C. It is available in 8-lead MSOP and 8-lead SOIC packages.