Interleaving Phase Shifters for Critical-Mode Boost PFC

Interleaving control schemes are widely used in converter applications. Merits of such control methods are in reducing input/output current or voltage ripples and volume, and increasing the processed power capacity of converters. For converters with constant frequency operation, it is easy to achieve interleaving control. However, it is difficult to realize interleaving features with variable frequency operation, such as boost-type power factor correctors (PFCs) operated in critical-mode (CM) condition. This paper proposes several interleaving phase shifters for CM boost PFCs. Analysis and design of the interleaving phase shifters are first described in detail. Moreover, simulated results of the CM boost PFCs with interleaving two-phase and four-phase shifters are introduced. Finally, experimental results of a two-phase interleaved CM boost PFC are presented to verify the discussed features.