Modeling and Simulation of Digital Control Schemes for Two-Phase Interleaved Buck Converters

Abstract

The importance of energy-efficient DC voltage conversionis ever increasing. This demands for advanced topologiessuch as time-interleaved multiphase DC-DC converters. Anessential part of such a converter is the control loop, which not only regulates the output voltage, but also balances the currents of the individual phases. In this paper, a small-signal model of a two-phase buck converter is derived, and a linear voltage-mode controller is presented. Further, a current balancing scheme that only requires input current sensing is investigated. Finally, the benefits of a multisampled controller and digital pulse width modulator are highlighted.