A Multi-Phase Multi-Path Hybrid SC Buck Converter With Enhanced DCR-Loss Reduction and Alleviated ICF Gathering for 9-48 V-Input PoL Conversions

Abstract

This article presents a multi-phase multi-path hybrid switched-capacitor (SC) buck converter for 9-48 V-input point-of-load applications. The proposed topology uses interleaved SC cells operating at a higher frequency than the high-voltage stage, resulting in phase-balanced capacitor charge/discharge, thereby mitigating the effects of SC current gathering. In addition, the multi-phase operation decouples the high-voltage-stress power cells from high-current-conduction paths, reducing the inductor current under high-step-down conversions. Fabricated in a 180-nm SOI process with 5.7mm², the proposed converter achieves a measured peak efficiency of 88.3% and a current density of 176 A/cm³ over an input range of 9-48 V and an output of 0.8-1.2 V, using only 11.35 mm³ in passive volume.