Ultra-Low Profile Hybrid Switched Capacitor Converter with Matrix Multi-Tapped Autostransformer

Abstract

In server AI application one of the biggest bottlenecks to keep up calculation capability is power management, hence high power density and high efficiency power supply are required. 48 V power-delivery architecture has been promoted to replace the 12 V power supply [1] where a two-stage approach is commonly adopted. First stage is typically implemented with an unregulated converter such as LLC or STC [2]. LLC converters with matrix transformer are suitable for these applications, however, where isolation is not needed a non-isolated resonant hybrid switched capacitor converter is a valuable candidate. In this paper a novel magnetic structure called matrix multi-tapped autotransformer is presented. This structure combines the benefit of matrix transformer with the advantages of hybrid switched capacitor structure. Experimental results for a 450 W prototype in 8th brick ultra-low profile factor achieving 1300 W/in3 power density, are proving the effectiveness of the proposed approach.