CCM Totem-Pole PFC for Ultra-High Power Density USB-PD Chargers

Abstract:
This paper presents a CCM totem-pole PFC to be used in USB-PD applications. The implementation of CCM instead of the traditional CrCM for this power range, simplifies the design and reduces the size of the EMI filter, enabling power density close to 90 W/in³ with a peak efficiency of 98.6%. On the contrary, the possibility of ZVS operation is considerably reduced compared to CrCM. This paper analyzes both aspects together with a robust implementation of bootstrapping for the GaN transistors, which considerably simplifies the driving and bias concept.