An AC-Coupled Stacked Dual Active Bridge Hybrid DC-DC Converter for Battery-to-Processor Power Delivery with 87.2% Peak Efficiency and High Accuracy Loadline Regulation

Abstract

This work presents a hybrid 3:1 DC-DC converter topology for power conversion directly from Li-ion battery to processor. The proposed topology enables the use of standard CMOS switches for achieving high voltage conversion ratios while utilizing the package interconnection as the effective inductor with minimum off-chip capacitors. The prototype achieves 87.2% peak efficiency with 83.4% at a power density of 0.46W/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> including the area of off-chip capacitors and demonstrates 50mV voltage perturbanion under a 0.4A on-die load step. Compared with state-of-the-art switched-capacitor and hybrid converters that operate under similar conversion ratios, this work demonstrates a wide voltage regulation range with competitive efficiency, power density and by-far the best transient performance.