A Reconfigurable Single-Inductor Multi-Stage Hybrid Converter for 1-Cell Battery Chargers

This article presents a reconfigurable single-inductor multi-stage (SIMS) hybrid step-down converter that efficiently provides a wide range of voltage conversion ratios (VCRs) needed for 1-cell battery charging across a wide input voltage range of 5–24 V while moving the inductor away from the high-output current path. The inductor is used to couple two synchronous switched-capacitor stages to provide soft charging benefits to each stage. A prototype was implemented in a
$0.18 \mu \text{m}$
bipolar, complimentary metal-oxide semiconductor, double-diffused metal-oxide semiconductor (BCD) process with a die area of 9.4 mm2. It extends reconfigurable switched-capacitor and merged multi-stage operation concepts to deliver a maximum output current of 5 A and achieves peak efficiencies of 94.8% and 92.4% from 5- and 24-V input supplies, respectively.