T15.2 - Survey of Components and Topologies for High-Efficiency and High-Power Density 48V DC-DC Converters

This survey examines fundamental components of 48 V DC-DC converters and recent publications. It compares properties of common discrete MLCCs and power inductors, confirming capacitors’ potential for up to 200 times higher energy density. Discrete GaN power transistors offer better volumetric conductivity than Si switches. Recent publications show highest efficiencies at low conversion ratios (4:1 or 6:1). Converters with output currents above 5 A typically use discrete power stages. The survey indicates the potential for higher conversion ratios for converters operating at lower currents. Efficient topologies include transformer-based and hybrid switched-capacitor converters. Hybrid switched-capacitor converter topologies using discrete components show the highest efficiency and power density simultaneously, while also effectively addressing high-power applications. The data set for all components and compared publications is made accessible on GitHub.