48V-to-12V Dual-Path Hybrid DC-DC Converter

A dual-path hybrid DC-DC converter with the step-down ratio of less than half is proposed for the first time. In the proposed converter, the efficiency is higher than a conventional buck converter, because the output current is divided into inductor- and capacitor-path and the conduction loss due to ESR of the inductor is reduced. In the measurement, the peak efficiency of the proposed dual-path hybrid and conventional buck converters was 97.1% and 96.0% at 120W, 48V-to-12V conversion, respectively, indicating the loss is reduced by 28.4 %. Furthermore, the efficiency of the proposed and conventional converters was 95.8% and 94.8% at 240W, respectively, indicating the loss is reduced by 30.0 %.