Patent ID: 8324875

Claim:
A multiphase DC/DC converter comprising: a plurality of DC/DC converters whose outputs are connected in common to supply electric power to a load; a load state detection portion which detects a state of the load connected to the plurality of DC/DC converters and outputs a load state detection signal; a comparator which compares an output voltage generated by the plurality of DC/DC converters and a reference voltage with each other, and outputs a comparison signal; a pulse signal generation portion which, based on the comparison signal, generates a pulse signal whose on time is fixed; and a pulse distribution portion which, based on the load state detection signal from the load state detection portion, distributes successively a pulse of the pulse signal as a drive signal for the plurality of DC/DC converters so as to drive the plurality of DC/DC converters such that output phases of the plurality of DC/DC converters are deviated from each other or such that the output phases of the plurality of DC/DC converters are aligned with each other, wherein an output stage of the pulse distribution portion includes: a first logical-multiply operation circuit arranged to output a first logical-multiply operation signal of the load state detection signal and a second drive signal, a second logical-multiply operation circuit arranged to output a second logical-multiply operation signal of the load state detection signal and a first drive signal, a first logical-sum operation circuit arranged to output a first logical-sum operation signal of the first drive signal and the first logical-multiply operation signal to a first DC/DC convertor, and a second logical-sum operation circuit arranged to output a second logical-sum operation signal of the second drive signal and the second logical-multiply operation signal to a second DC/DC convertor, wherein the first and second drive signals are generated by successively distributing pulses of the pulse signal.