Balance Technique for MHz Critical Mode PFC Rectifier with Coupled Inductor
The coupled inductor has been widely adopted in VR applications for many years because of its benefits, which include reducing current ripple and improv-ing transient performance. In this presentation, the coupled inductor concept is applied to an interleaved MHz Totem-pole CRM PFC converter with GaN devices. The coupled inductor in the CRM PFC converter can reduce switching frequency variation, which helps to achieve ZVS, and reduce circulating energy. Hence, the coupled inductor can improve the performance of the PFC converter. In addition, a balance technique is applied to help minimize the CM noise. Previously, the balance technique was developed for an interleaved boost PFC converter with independent inductors. This presentation will introduce how to achieve balance with a coupled inductor. The inductor design procedure and FEA simulation will be provided.