Abstract: The semi-bridgeless dual Boost power factor correction（PFC）circuit can obtain higher conversion

efficiency without increasing common mode noise，but the return current of the input AC terminal produces

additional losses on the introduced diodes，which reduces the conversion efficiency. The replacement of diodes with

MOS transistors was investigated. The MOS transistor was with very low impedance when turned on to short-circuit

the MOS transister（or its body diode）and the inductor branch in parallel. Most of the return current was flowed

through the introduced MOS transistor，the conduction loss was reduced and the conversion efficiency was

improved. At the same time，a low impedance path was provided for the common mode noise through the MOS

transistor and its body diode，and the commonmode noise level was not changed. The working process and design

criteria of the circuit were given，and the correctness of the analysis was verified by circuit simulation. Finally，a 1.5

kW principle prototype was developed，in which it was verified that the circuit can further improve the conversion

efficiency.

      Key words: semi-bridgeless power factor correcttion；self-drive synchronous rectifier；high efficiency