300A Single-stage 48V Voltage Regulator with Multiphase Current Doubler Rectifier and Integrated Transformer

High-current, high-power-density 48V voltage regulator modules (VRMs) are critical for 48V data center power architecture. In the paper, a single-stage 48V converter with multiphase current doubler rectifiers is proposed for CPUs in data center applications. The magnetizing inductors of the matrix transformer are used as the output inductors of the multiphase current doubler rectifier. A magnetic integration structure for the matrix transformer is proposed and optimized, which creates negative coupling between multiphase current doubler rectifiers. With GaN devices as primary side devices and low voltage silicon devices as secondary synchronous rectifiers (SRs), the proposed converter can achieve high efficiency and high power density. A 48/1.8V 300A converter is designed, which can reach an estimated peak efficiency of 93% and a power density of 1.9 kW/in³.