Isolated and Regulated Ultra-Flat DC–DC Power Converter for Extremely Wide Input Voltage Range (15 V–150 V), High Gain and Demanding Dynamics

Abstract

This article proposes an isolated ultra-flat DC–DC converter architecture capable of directly converting high-voltage distribution rails (15–150 V) into regulated sub-1 V outputs with extremely high voltage conversion ratio. The solution is based on a resonant single-transformer structure specifically designed to enable large step-down operation while minimizing conduction path complexity. A 12:1 turns ratio with a single-turn secondary and reduced primary turns allows high gain realization using only one magnetic component and a minimized number of series devices along the main current path. The complete hardware implementation achieves a total height of 3.5 mm, making it compatible with surface power delivery and direct-to-chip integration constraints. An improved version incorporating a secondary-side active clamp is introduced to enhance controllability and transient behavior without increasing magnetic complexity. Both implementations are experimentally validated and quantitatively compared under equivalent operating conditions. The results demonstrate the feasibility of achieving extreme gain, wide gain variation, and ultra-low-profile integration using a single-magnetic isolated architecture suitable for future high-performance computing and AI processors.