Research On Totem-Pole Bridgeless PFC Converter

Due to the rapid development of mobile communication technology, telecom power supplies have been widely applied in telecom system. Traditionally, telecom power supply consists of a PFC stage and a DC/DC stage. The most widely used solution to PFC stage is the Boost PFC circuit working in CCM with average current control, which is quite mature and has reached its performance limit. In an attempt to further improve the efficiency of PFC stage, increasing researches have been focused on bridgeless PFC circuits, which improve PFC efficiency by eliminating the input diode bridge and its conduction loss.In this paper, some typical bridgeless PFC topologies will be analyzed and compared in aspects of common mode noise, driving difficulty and component count. According to the above analysis, thorough research will be conducted on totem-pole bridgeless PFC topology, which has a promising application prospect.Totem-pole bridgeless PFC topology enjoys low common mode noises and low component count. However, the fact that body diode of MOSFET is used as freewheeling diode prevents it from working in CCM. It can only work in DCM or CRM. In order to apply totem-pole topology to practical products, in-depth study on totem-pole bridgeless PFC converter will be carried out, including its digital control scheme, zero current detection, compensation for reverse recovery of body diode, driving scheme, etc. Finally, experimental results based on prototype will be showed to verify the proposed schemes.