Design of Direct 48-V/1-V Three-Path Four-State Switching Power Converter With Adaptive VCF Rebalancing and Dual-Edge tdead Modulation Yuanqing Huang , Student Member , IEEE

Abstract

This article presents a new power converter capable of direct 48-V/1-V dc–dc conversion with high efficiency. The proposed three-path four-state (3P4S) hybrid switching power stage enables high switching frequency ( fSW) operation and minimizes power passives by significantly reducing power switch voltage stress. To address the issues of power delivery path imbalances and potential device breakdown, an adaptive flying capacitor voltage ( VCF) rebalancing technique is introduced that improves design robustness and eliminates the need for direct floating VCF sensing. Additionally, a dual-edge deadtime ( tdead) modulation with elastic tdead control at switching nodes optimizes converter efficiency across different input voltage and load conditions. An IC prototype of the design was fabricated and tested with input voltage VIN ranging from 12 to 48 V , delivering up to 4 W of power at 1-V VO. It achieves peak efficiency of 90.7% and 85.6% for 12-V/1-V and 48-V/1-V power conversion, respectively, at an effective switching frequency of 4.5 MHz, which is based on a three-phase operation with each phase at 1.5 MHz. The adaptive VCF rebalancing technique reduces VCF imbalance error by up to 65.1%. Overall, the proposed 3P4S hybrid switching power converter offers an efficient and robust solution for direct dc–dc conversion with a wide VIN range.