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

Vast design spaces with numerous topologies and parameter requirements make optimal DC-DC converter design choices and comparisons challenging. Despite their variety, DC-DC converters share fundamental components. To this end, trends and relationships between passive components are investigated in the survey presented in this paper. The potential for 200 times higher energy density in multilayer ceramic capacitors (MLCCs) compared to discrete power inductors is confirmed. The survey also shows higher volumetric conductivity in discrete GaN switches compared to Si switches. Recent publications on 48 V DC-DC converters are investigated in order to identify topologies capable of achieving high efficiency and high power density. Hybrid switched-capacitor converters emerge as promising candidates, demonstrating the potential to achieve both goals simultaneously, while also meeting the demands of high-power applications.