Single-Stage 48 V/1.8 V Converter With a Novel Integrated Magnetics and 1000 W/in<sup>3</sup> Power Density
Xin Lou, Qiang Li
Abstract
High-efficiency, high-power-density 48-V voltage regulator modules are crucial and also challenging for 48-V data center power architecture. In this article, a novel single-stage 48 V/1.8 V converter for high-performance microprocessors is proposed, offering ultrahigh power density and high efficiency. The converter utilizes a novel magnetic structure that integrates the transformers and four-phase coupled inductors of two current doubler rectifiers. The magnetic structure design guidelines highlight the tradeoff between the coupling coefficient and magnetic core size. To minimize core and winding losses while maintaining compactness, small core legs are employed in corner areas, replacing the bulky leakage legs. In addition, the printed circuit board winding arrangement is optimized, with the use of buried vias further reducing winding loss. Finally, a 48 V/1.8 V prototype is designed with 93.1% peak efficiency and 1037 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> power density, including its gate driver loss and size. The prototype can handle 120 A continuous current and 300 A peak current for 2 ms × 62 Hz, with 500 linear feet per minute air cooling.