CPLD and dsPIC Hybrid-Controller for Converter Prototyping driving a Reconfigurable Transformer Phase-Shifted Full-Bridge

Abstract:
The development of recent high-efficient power converters leads to novel multi-switch topologies. To allow precise control of multiple switches, high-resolution PWM signals are required. Today, DSCs already provide PWM signal generation with 250 ps resolution. Nevertheless, limitations prevent them from meeting new converter topologies. Still, they are a promising choice for prototyping compared to FPGAs in terms of cost, footprint and complexity. To overcome these limitations, a hybrid-controller with a dual core dsPIC DSC and a CPLD was designed. The presented controller is optimized for a wide-range converter with reconfigurable transformer configuration. Since it is very versatile, easy to configure and fabricate, it can also be used for prototyping of many other converter topologies. In addition to the regular DSC features, it adds dynamic signal routing, logic and synchronization capabilities. The proposed hybrid-controller is described, experimentally verified and compared to a purely DSC based controller when driving a phase-shifted full-bridge with reconfigurable transformer. To estimate the component stress, the generated PWM waveforms were captured and fed into a spice simulation of the converter.