A 12/24 V-Input HV-LV-Separated Hybrid SC PoL Converter With 355 mW/mm3 Power Density at 3 A Load Current and 15.2 mm3 Power Passives

This letter presents a high-power-density point-of-load dc–dc converter for 12/24 V input applications, using the proposed high voltage-low voltage separated hybrid switched-capacitor (SC) topology. By incorporating inductors between the SC networks in HV/LV domains, the design achieves reduced inductor dc current (
I
_L,DC
) at small voltage conversion ratios (VCRs), optimized switching and conduction losses, and extended duty ratio range, enabling the use of small-sized inductors with higher dc resistance and resulting in a compact system volume. LV switches handle most of the current conduction, reducing switching losses and silicon area for higher on-chip power density. The fabricated converter, using a 180-nm BCD process, generates 0.8–1.8 V output from 12/24 V inputs with a 3-A maximum load. Measured results show total
I
_L,DC
of 1.2 A at VCR 0.075 and 2 A load. The converter achieves a peak power density of 355 mW/mm
³
with a power passive volume of 15.2 mm
³
. Peak efficiencies are 85% at 12 V input and 84.2% at 24 V input.