Very High Common-Mode Voltage Precision Difference Amplifier

The AD8479 is a difference amplifier with a very high input common-mode voltage range. The AD8479 is a precision device that allows the user to accurately measure differential signals in the presence of high common-mode voltages up to ±600 V.

The AD8479 can replace costly isolation amplifiers in applications that do not require galvanic isolation. The device operates over a ±600 V common-mode voltage range and has inputs that are protected from common-mode or differential mode transients up to ±600 V.

The AD8479 has low offset voltage, low offset voltage drift, low gain drift, low common-mode rejection drift, and excellent common-mode rejection ratio (CMRR) over a wide frequency range.

The AD8479 is available in a space-saving 8-lead SOIC package and is operational over the −40°C to +125°C temperature range.

Applications

* High voltage current sensing

* Battery cell voltage monitors

* Power supply current monitors

* Motor controls

* Isolation

* ±600 V common-mode voltage range

* Rail-to-rail output

* Fixed gain of 1

* 550 μA typical power supply current

* Excellent ac specifications

* 90 dB minimum CMRR

* 310 kHz bandwidth

* High accuracy dc performance

* ±5 ppm maximum gain nonlinearity

* ±10 µV/°C maximum offset voltage drift

* ±5 ppm/°C maximum gain drift