Multi-phase Converter for Wide Range of Input Voltages with Integrated Filter Inductor

This paper presents results of the analysis and design of a multi-phase buck converter with integrated filter inductor when operated with a wide range of voltage conversion ratios. Included are the analysis of the converter input and output currents to optimize the required filter capacitors, the analysis and design of the integrated filter inductor and results of a state-space controller that provides robust control of the output voltage for the required wide range of input voltages and loads ranging from full to no-load conditions. The influence of the wide range of input voltages to the operation of the converter is demonstrated. A prototype converter with four phases and an integrated filter inductor has been built and tested to verify predictions from the analysis.