High Power Density High Current Density LLC-DCX Converter for Datacenter Application

Abstract

This paper presents a high-efficiency LLC resonant bus converter with a 10:1 step-down ratio, tailored for 48 V data center applications. To address the challenges of power density and current density, a compact design was achieved by employing a single-PCB planar transformer and a high-density integration scheme, significantly reducing the converter's footprint compared to conventional approaches. Furthermore, a primary winding connection method for current sharing and a copper-plated secondary termination design were proposed. The implemented prototype demonstrates excellent performance: with a 48 V input, it delivers a maximum output current of 85 A and a peak efficiency of 98.8%; under 60 V input conditions, the converter achieves a current density of 0.29 A/mm² and a power density of 3548 W/inch³.