The ADuM31901 is an isolated error amplifier based on Analog Devices， Inc.， iCoupler? technology. The ADuM3190 is ideal for linear feedback power supplies. The primary side controllers of the ADuM3190 enable improvements in transient response， power density， and stability as compared to commonly used optocoupler and shunt regulator solutions. Unlike optocoupler-based solutions， which have an uncertain current transfer ratio over lifetime and at high temperatures， the ADuM3190 transfer function does not change over its lifetime， and it is stable over a wide temperature range of ?40°C to +125°C. Included in the ADuM3190 is a wideband operational amplifier for a variety of commonly used power supply loop compensation techniques. The ADuM3190 is fast enough to allow a feedback loop to react to fast transient conditions and overcurrent conditions. Also included is a high accuracy 1.225 V reference to compare with the supply output setpoint. The ADuM3190 is packaged in a small 16-lead QSOP package for a 2.5 kV rms isolation voltage rating.