Analysis and Design of the LmC Resonant Converter for Low Output Current Ripple

In this paper, an LmC resonant converter is proposed for low output current ripple, and its steady-state analysis and design guidelines are investigated. In the LmC converter, the current stress of the output capacitors is reduced due to the inductive output filter, and the series resonant inductor is removed while maintaining the benefits of an LLC resonant converter such as zero-voltage switching and narrow switching frequency range. The mode analysis is described, and the steady-state characteristics are explored using the extended describing function. Based on the result, the design guidelines are suggested. A 240-W 24-V/10-A hardware prototype is built and tested to verify the analysis results and to evaluate the performance of the LmC resonant converter.