Multiphase buck converter with current balancing

Abstract

A multi-phase buck voltage regulator includes first and second buck converters, first and second low pass filters, and a current balancing loop circuit. The first buck converter includes a first pair of power transistors and a first switch node. The second buck converter includes a second pair of power transistors and a second switch node. The low pass filters are coupled to their respective switch nodes. The current balancing loop circuit receives a filtered output of each filter. The current balancing loop generates a current balancing current signal to control a gain of a first voltage-to-current converter for the second buck converter. The duty cycle of the second buck converter is thereby adjusted, which in turn adjusts a current of the second buck converter to become closer to a current of the first buck converter.