Patent ID: 7443147

Claim:
A DC-DC converter control apparatus for controlling a DC-DC converter to convert an input voltage into a predetermined output voltage by making said DC-DC converter execute at least one of a plurality of kinds of PWM controls, comprising: a differential output circuit for generating a signal corresponding to a difference between an output voltage and a predetermined voltage; an offset change circuit for receiving the signal generated from the differential output circuit, and for changing offset of ON/OFF switching timing for PWM control on the basis of a kind of said plurality of PWM controls under execution by said DC-DC converter; an oscillator for generating a triangular wave signal; a step-up comparator circuit for comparing signals generated from said oscillator and said differential output circuit and generating a step-up PWM control signal corresponding to a comparison result; and a step-down comparator circuit for comparing signals generated from said oscillator and said differential output circuit and generating a step-down PWM control signal corresponding to a comparison result, wherein said plurality of kinds of PWM controls includes step-up PWM control, step-down PWM control, and both of step-up PWM control and step-down PWM control, and wherein said offset change circuit changes offset of the triangular wave signal generated from said oscillator so as to change offset of ON/OFF switching timing for step-up PWM control and/or offset of ON/OFF switching timing for step-down PWM control on the basis of a kind of PWM control under execution by said DC-DC converter.