Abstract

Industrial applications such as motor drives, photo voltaic inverters, and uninterruptible power supplies (UPS) and automotive applications such as onboard chargers (OBCs), traction inverters, and DC/DC converters operate at high voltage and current levels to optimize overall efficiency and power throughput. These systems are subjected to hostile environments such as electrical noise, vibration, mechanical shock, extreme temperatures, ingress of contaminants, and so forth. Such systems demand robust, reliable, galvanic isolation to isolate high voltages from low-voltage circuits. The feedback signals measured on these high voltages are galvanically isolated from the low-voltage controllers by isolated amplifiers or isolated modulators.

This document compares isolated amplifiers and isolated-modulator-based designs and explains some unique advantages of isolated-modulator-based designs.