A multiplexed feedback solution for isolated digital power supplies

Abstract

As digital power supply became a significant market opportunity, manufacturers started looking at ways to control the system cost by reducing components and their technical requirements. This thesis proposes a multiplexed digital feedback solution for isolated digital power supply systems. Several digital isolators used in existing applications can be reduced to one. The data transmission speed is greatly reduced. The communication protocol is DC-balanced; therefore pulse-transformer type digital isolators can be used resulting in further lower cost. The proposed solution also improves output accuracy over existing solutions. Presentation of the proposed system will be in three parts: architecture, protocol, and Piece-wise Linear Feedback method. Both theoretical analysis and practical implementation will be discussed, and the simulation results included support the theoretical analysis. A prototype board was built and its performance is promising.