A 90.7% 4-W 3P4S Hybrid Switching Converter Using Adaptive VCF Rebalancing Technique and Switching Node Dual-Edge tdead Modulation for Extreme 48V/1V Direct DC-DC Conversion

This paper reports a 3-path 4-state (3P4S) hybrid switching converter for extreme 48V/1V direct power conversion. Compared to classic half-bridge topology, the 3P4S topology extends on-time TON by 9 times with 67% RMS current reduction. It also employs the fewest conducting switches in every discharge path and allows lower voltage rating and faster switches than the peers, facilitating high f
sw
operation, high efficiency, small power passives and low chip area. To prevent over-voltage stress and thermal breakdowns, an adaptive VCF rebalancing technique is introduced to reduce the VCF1 and VCF2 imbalance errors by 57.1% and 65.1%, respectively. To enable zero-voltage switching (ZVS) for high efficiency, a dual-edge t
dead
modulation is implemented at key switching nodes. The converter was fabricated in a 180nm HV BCD process, with an active area of 3.3mm
²
. It delivers 4W power with a peak efficiency of 90.7% and an effective f
SW
of 4.5MHz.