Digital control of dual output interleaved PFC using single input current sense

In this paper the control aspects of dual output interleaved PFC converter with single current sense is discussed. As well known, the interleaved PFC topologies have been widely used since they allow for smaller components, improved thermal performance, increased critical conduction mode power range, better transients and reduced current ripple. In this study, a two-phase interleaved PFC topology running with universal input range is modified to obtain dual independent outputs for servers and telecom applications. A low cost microcontroller (TMS320F28027-PiccoloA) is used to implement complete digital control of the interleaved PFC system. In this dual-output PFC concept, the control electronics, the input voltage sense circuits and the current sense circuits are shared between two PFC power stages. This minimizes the size and the cost of the design significantly.