Efficiency-Based Auto-Tuning of Current Sensing and Sharing Loops in Multiphase Converters

Multiphase converters require a current-sharing loop to maintain equal or desired current sharing between phases or paralleled modules. The current-sharing loop is highly sensitive to current-sensing accuracy. In this letter, a method is presented to achieve auto-tuning of the current-sharing loop in multiphase converters while adaptively calibrating the current sensing based on power conversion efficiency. This is achieved without the need for a precise calibration reference or resistor and with no dependency on sensing accuracy. A digital controller implementation of the method is described and experimental results are obtained for a 0.84 V/30 A two-phase buck voltage regulator.