Differential Amp Serves High-Voltage Apps

Designed to operate in areas subject to high common-mode voltages, the AD629 high-input, common-mode voltage differential amplifier serves motor control and power supply current monitoring applications. The device can be used to extract a small differential signal, such as the output current of a motor measured across a shunt resistor, in the presence of a high common-mode voltage. And its inputs can be raised or lowered more than 250V above or below the supply voltage, allowing damage-free operation in applications with transients as high as ±500V. By isolating the device's output circuitry from high input voltages, the differential amp provides a simple solution for protecting a range of end user equipment from irregular high voltages. Available in either an 8-pin DIP or SOIC package, the differential amplifier costs $4.00 each/1000.