Miniaturized Low-Voltage Power Converters With Fast Dynamic Response

Abstract

This paper demonstrates a two-stage approach for power conversion that combines the strengths of variable-topology switched capacitor techniques (small size and light-load performance) with the regulation capability of magnetic switch-mode power converters. The proposed approach takes advantage of the characteristics of complementary metal–oxide–semiconductor (CMOS) processes, and the resulting designs provide excellent efficiency and power density for low-voltage power conversion. These power converters can provide low-voltage outputs over a wide input voltage range with very fast dynamic response. Both design and fabrication considerations for highly integrated CMOS power converters using this architecture are addressed. The results are demonstrated in a 2.4-W dc–dc converter implemented in a 180-nm CMOS IC process and co-packaged with its passive components for high performance. The power converter operates from an input voltage of 2.7–5.5 V with an output voltage of ≤1.2 V, and achieves a 2210 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{3}$ </tex-math></inline-formula> power density with ≥80% efficiency.