This talk will present a multi-mode control algorithm for totem-pole bridgeless power factor correction (PFC): the PFC operates at continuous conduction mode (CCM) at heavy load or at AC peak, and triangular current mode (TCM) with zero voltage switching (ZVS) at light load or around AC zero-crossing. In addition, a revised average current mode controller generates PWM for both CCM and TCM operation, resulting a smooth mode transition without any input current distortion. This multi-mode operation combines the advantages of both CCM and TCM operations, resulting in a high efficiency and high power density totem-pole bridgeless PFC solution. The proposed control method was implemented in a 3.6 KW totem-pole bridgeless PFC, it not only achieved >180 W/in3 power density, but also improved the light load efficiency up to 2%.
