In this invention, the inductors of multiphase PFC converters are coupled and integrated into one magnetic core. The coupling can improve converter efficiency. With a novel structure, the inductors can be built with PCB winding with similar loss as traditional litz wire inductors. In addition, balance technique is applied to reduce common mode EMI noise. This invention can be used in power supply for laptop, desktop, server, telecom datacenter and battery charger for electric vehicle.