Optimal Design of Integrated Planar Inductor for a Hybrid Totem-Pole PFC Converter

Optimal design of the planar integrated inductor is presented for a hybrid totem-pole bridgeless power factor correction (PFC) converter with a high frequency GaN-based switching leg and a low frequency Si-diode-based switching leg. The switching frequency of the PFC converter can be up to MHz by adopting critical mode (CRM) soft-switching operation mode. In order to achieve lower height and high power density, the inductor is split into two small inductors and then implemented with a planar integrated magnetic core. Footprint and power loss of the inductor with different magnetic core structure are analyzed and compared. Optimal design method of the integrated inductor is presented as well. Finally, a 700kHz 400W PFC converter is designed and tested to verify the effectiveness of the hybrid totem-pole bridgeless PFC converter with a planar integrated inductor.