Integrated 4-Level Dual-Phase Superimposed Quadratic Power Converter for High-Density Direct 48V/1V Conversion

Recent hybrid power converter topologies have encountered significant design and performance challenges for high step-down DC-DC power conversion. To minimize power passives and achieve high power density, both high switching frequency (f<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SW</inf>) operation and single-stage conversion are preferred; however, the resulting high step-down ratio imposes extremely short ON-time (T<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf>), which limits the maximum achievable f<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SW</inf>. To address these, this paper presents a novel 4-level dual-phase superimposed quadratic (4-LDPSQ) converter topology, which significantly extends TON and enhances efficiency by reducing voltage stresses on switches and optimizing RMS currents with parallel multipath power delivery. A prototype of this work, designed in a 0.18μm HV-BCD process, demonstrates direct 48V-to-1V conversion with a maximum IO of 5A at 5MHz, a peak efficiency of 88.28%, and power density of 69mW/mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, representing ×9.35 power density improvement and ×13.9 T<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> extension over a conventional half-bridge (HB) topology.