Optimal Lowest-Voltage-Switching for Boundary Mode Power Factor Correction Converters

This paper presents an optimal lowest-voltage-switching technique for boundary mode power factor correction (PFC) converters. The proposed approach minimizes the switching loss of the power MOSFET without additional discrete components. Optimal zero-voltage-switching or valley-switching can be achieved for universal input range. The gate driver delay can also be taken into account. A boundary mode boost PFC converter with the proposed optimal switching technique has been implemented using a 0.5-μm N-well process. Experimental results show that the proposed approach can realize optimal soft switching, and improve the efficiency of the boost PFC converter. The proposed lowest-voltage-switching technique can be applied to other resonant converters as well.