600-V GaN HEMT targets PFC off-line power supply

摘要

The promise of higher efficiency power conversion using GaN (gallium nitride) high electron mobility transistors (HEMT) has been achieved with devices now in volume production. This article describes the totem pole PFC and LLC dc/dc converter circuits that take advantage of the high-frequency switching speed, low on-state resistance (RDS(on)) and extremely low reverse-recovery charge (Qrr) of GaN HEMT switches, resulting in a combined overall efficiency exceeding 97%.