Hybrid Low-Frequency Switch for Bridgeless PFC

Abstract

Traditionally, for the bridgeless PFC, the low-Ron Si super-junction (SJ) mosfets are utilized to reduce the loss on the low-frequency switches. However, the high cost of the low-Ron Si SJ mosfet is an issue. Therefore, this letter proposes a hybrid low frequency switch which hybrids a high-Ron and low-cost Si SJ mosfet and a high current and low-cost Si diode. This hybrid switch achieves the low conduction loss under light load conditions due to the internal mosfet and achieves the low conduction loss under heavy load conditions due to the parallel diode. This hybrid switch combines the benefits of the mosfet and the diode with very low cost. This switch is very suitable for the high-efficiency bridgeless PFC rectifiers. The analytical and the experimental results based on the implemented hybrid switch verify the performance of the hybrid switch.