Wide-bandwidth digital controller for multi-phase converters

Abstract

DC-DC converters with high bandwidth are essential for today's high efficiency and high-speed micro-processing applications. In order to satisfy the requirements of those systems, we propose the implementation of a practical wide bandwidth digital controller for multiphase buck converters. Traditional implementations of multiphase converters have a performance comparable to single-phase implementations, with a bandwidth limited to a fraction of the per-phase switching frequency Fsw. The goal of this project is to take advantage of multiphase to achieve a higher bandwidth for any given switching frequency. Specifically, we target a bandwidth that scales with N x Fsw, rather than Fsw, with N being the number of phases in the system. This work focuses on the evaluation of a previously proposed digital modulator that is able to react to duty cycle changes at a speed equal to N x Fsw. Using this modulator, we design a few digital controllers and compare their performance to that of traditional digital controllers.