The AD629 is a difference amplifier with a very high input, common-mode voltage range. It is a precision device that allows the user to accurately measure differential signals in the presence of high common-mode voltages up to ±270 V.The AD629 can replace costly isolation amplifiers in applications that do not require galvanic isolation. The device operates over a ±270 V common-mode voltage range and has inputs that are protected from common-mode or differential mode transients up to ±500 V.The AD629 has low offset, low offset drift, low gain error drift, low common-mode rejection drift, and excellent CMRR over a wide frequency range.The AD629 is available in low cost, 8-lead PDIP and 8-lead SOIC packages. For all packages (including die) and grades, performance is guaranteed over the industrial temperature range of −40°C to +85°C.ApplicationsHigh voltage current sensingBattery cell voltage monitorsPower supply current monitorsMotor controlsIsolation