Patent ID: 8058856

Claim:
A multi-phase DC-DC converter, comprising: a plurality of switching sets for generating an output voltage at an output, wherein each switching set comprises a phase node; a plurality of output inductors separately coupled between the phase nodes and the output; a sense circuit having a plurality of sense units separately coupled to the phase nodes, each sense unit for sensing a signal from the corresponding phase node and generating a sensing signal according to the signal from the corresponding phase; and a PWM generator for generating a plurality of PWM signals to balance a plurality of currents of the output inductors, comprising: an error amplifier for comparing a reference voltage with the output voltage to generate an error signal; a plurality of calculating circuits, each comprising: a subtracting unit for subtracting a first signal from one of the sensing signals to generate a difference signal, wherein the first signal is generated by summing each of the sensing signals divided by a predetermined value except for the one of the sensing signals; and a summing unit for summing the difference signal and a ramp signal to generate a second signal; and a plurality of comparators separately coupled to the calculating circuits, each comparing the error signal with the corresponding second signal to generate the PWM signal, wherein the switching sets generate the output voltage according to the PWM signals, and each of the difference signals is greater than 0.