High efficiency high density telecom rectifier with GaN device

Efficiency and power density are the two most important index of the telecom rectifier development. During recent years, the efficiency of the telecom rectifier is pushed from 92% to 96% and now 98%, this paper however explores the design considerations of super high density (100W/inch
³
) telecom rectifiers in concert with high efficiency requirements (96%). Specifically, the design considerations of a high switching frequency (1MHz) and high efficiency interleaving totem pole PFC stage with DCM boundary control followed by a high resonant frequency (500kHz), PCB winding based LLC DCDC stage is explained. The wide band device 650V GaN HEMT is used for both PFC stage and D2D stage. Experimental results are presented to validate the design concept to meet the power density and efficiency target.