48 V-to-12 V Always-Dual-Path Hybrid DC-DC Converter for Inductor Current Reduction
Katsuhiro Hata, Shinsaku Tanaka, Yasuhiro Rikiishi, Takashi Matsumoto
Abstract
A novel circuit topology for 48 V-to-12 V always-dual-path hybrid (ADPH) DC-DC converters is proposed using one inductor and two flying capacitors with only two circuit states to reduce the inductor DC current by 50 % compared to a conventional buck converter. The loss analysis shows that the proposed ADPH converter can achieve higher efficiency than the conventional buck converter over the entire output current range of the 48 V-to-12 V conversion. In the measurement, the efficiency at 15 A <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</inf> full load of the prototype converter was improved by 2.3 points from 95.6 % to 97.9 %. Then, the inductor conduction loss due to the inductor DC resistance was reduced by 76.2 % by reducing the inductor DC current by 50.9 % compared to the conventional buck converter.