Direct 48V to 1V Step-Down DC-DC Converter

A new solution based on switched-capacitor (SC) to convert 48 V to 1 V is presented herein for data center applications. The topology integrates four ladder SC cells and a Buck converter. All stages are connected in cascade and thus the topology provides a high gain ratio with good output voltage regulation. The work propos a modification of the ladder SC cell, which allows the cascade connection with a reduced number of components making simples integration among the cells. The SC stages convert from 48 V to 3 V and the Buck stage changes 3 V to 1 V, and thus the proposed structure uses switches, capacitors and just one inductor (from Buck stage). These features make the structure adequate to be built in an integrated circuit (IC). In addition, the power rating may be increased by adding more converters in parallel. The paper discusses the topology, static gain, voltage stresses, modeling, efficiency, and a comparison with the ladder association of SC (commonly used). The topology was verified by simulation results under 20 A in output current with Gallium Nitride (GaN).