High Common-Mode Voltage Difference Amplifier

The INA117 is a precision unity-gain difference amplifier with very high common-mode input voltage range. The INA117 is a single monolithic IC consisting of a precision op amp and integrated thin-film resistor network. The device can accurately measure small differential voltages in the presence of common-mode signals up to ±200V. The INA117 inputs are protected from momentary common-mode or differential overloads up to ±500V.

In many applications, where galvanic isolation is not essential, the INA117 can replace isolation amplifiers. This design can eliminate costly isolated input-side power supplies and the associated ripple, noise, and quiescent current. The 0.001% nonlinearity and 200kHz bandwidth of the INA117 is superior to those of conventional isolation amplifiers.

The INA117 is available in 8-pin plastic mini-DIP and SO-8 surface-mount packages, specified for the –40°C to 85°C temperature range.