A High Efficiency and High Current LLC Resonant Converter with Improved Interleaving Winding Arrangements

This paper proposes a magnetic core geometry with merged winding layouts for a 30/5V 660W LLC resonant converter used in data centers. It enables only one turn for both primary and secondary windings to realize the 6:1 turns ratio. The resonant capacitors are integrated into primary windings to reduce the winding loss and the converter footprint. The merged winding is applied to secondary windings. Compared with the state-of-the-art, the proposed winding layout illustrates more effective proximity effect reduction, smaller footprint, lower DC and AC resistances. The experiment results show that the prototype achieves a peak efficiency of 97.7%.