A New 8x Matrix Autotransformer Switched Capacitor DC-DC Converter for Datacenter Application

This paper proposes an 8x matrix auto-transformer switched-capacitor DC-DC converter (MASC) to achieve a high voltage conversion ratio, high efficiency, and high power density for 48-V data-center applications. On the high-voltage side, the proposed converter can fully leverage the benefits of high-performance low voltage stress devices similar to the multilevel modular switched-capacitor converter. On the low-voltage side, the current doubler instead of full bridge is adopted to decreases the devices count. For the less than 8-V low output voltage application, the current doubler rectifier design can fully utilize the best figure-of-merit 25-V device, which is more efficient than the full-bridge rectifier solution using two 25-V devices during the operation. A 500-W 48-V to 6-V DC-DC converter hardware prototype has been developed with optimized device selection and integrated matrix auto-transformer design. Both simulation and experiment results have been provided to validate the features and benefits of the proposed converter. The maximum efficiency of the MASC can reach 98.33% with power density as 767.4W/in
³
.