Design of GaN-based MHz totem-pole PFC rectifier

Totem-pole bridgeless power factor correction (PFC) rectifier is recently recognized as a promising front end candidate for applications like server and telecommunication power supply. In this paper the advantage, enabled by emerging high-voltage gallium-nitride (GaN) devices, of totem-pole PFC rectifier comparing to traditional PFC rectifier is discussed in the beginning. Critical mode operation is used by the totem-pole PFC rectifier in order to achieve both high frequency and high efficiency. Then several high frequency issues and detailed design considerations are introduced including zero-voltage-switching (ZVS) extension for entire line-cycle ZVS operation; variable on-time strategy for zero-crossing distortion suppression; and interleaving control for ripple current cancellation. The volume reduction of differential-mode (DM) electro-magnetic interference (EMI) filter significantly benefited from MHz high frequency operation and multi-phase interleaving is also presented. Finally, a 1.2kW GaN-based MHz totem-pole PFC rectifier is demonstrated with 99% peak efficiency and 200W/in³ power density.