A 90.6% Efficient, 0.333 W/mm2 Power Density Direct 48V-to-1V Dual Inductor Hybrid Converter with Delay-line Based V2D Controller

Abstract

This brief presents a 48V-to-1V 10-level dual inductor hybrid converter (DIHC) containing 11 on-chip switches and an off-chip gallium nitride (GaN) switch. Thanks to the 10-level Dickson switched-capacitor (SC) circuit, most of the voltage stress will be taken over by off-chip capacitors, which reduces the voltage stress of each switch to 4.8 V and takes full advantage of the voltage pressure on the 5-V on-chip transistors. This proposed structure is implemented in a 0.18- $\mu \text{m}$ BCD process to convert 48-V input to 1-V output with up to 18-A current load. The post-layout simulations show that a peak power efficiency of 90.6% can be achieved at 5.2-A loading and the power density is about 0.333 $W/mm^{2}$ considering the power stage area.