CPLD realization of a digital programmable PFC control IC for single-phase half-bridge boost AC-DC converters

In this paper we present a digital programmable PFC control IC for single-phase half-bridge boost AC-DC converters, employing an Altera Flex 10K100 CPLD device. We also propose a multiple-loop control scheme for this PFC control IC to achieve a near-unity power factor under large load variations. The control scheme is simple in architecture and thus facilitates realization of the proposed digital controller using the CPLD-based circuit design approach. We adopted hierarchical, modular, and circuit resource concurrency design method for reducing the design complexity of the control IC. Owing to the high-speed nature of the CPLD, the sampling frequency of the constructed IC can be raised up to the range that cannot be achieved using a conventional microprocessor-based digital controller. Besides, the control parameters in this IC are programmable and the variables can be observed via an interface to a monitoring processor. Simulation and experimental results are presented to verify the viability of the proposed control IC.