Optimal Design of Hexagonal Matrix Transformer for 48V-1V Switched-Capacitor and Series-Resonant Converter

Switched-capacitor and series-resonant converter (SCSRC) is a promising topology to achieve single stage 48V-1V power conversion in 48V data center applications. This is mainly because of its high step down ratio, excellent soft-switching characteristics, and high efficiency. However, it is challenging to optimal design its transformer due to the high step down ratio and large output current. To address this challenge, in this paper, we propose a hexagonal matrix transformer and its optimal design methodology. The hexagonal matrix planar transformer is derived by merging multiple EI cores, which results in 40% reduction in primary side winding loss and 10% reduction in footprint. A guideline is detailed to facilitate the design process. A hardware prototype that operates at 950kHz, 48V input and 1V/100A output is designed and tested. Experimental results validate the design methodology and functionality of the transformer with an 87.73% peak efficiency.