Patent ID: 7501802

Claim:
A DC-DC converting apparatus comprising: a step-up and step-down circuit configured to step-up and step-down an input voltage to generate and output a predetermined output voltage; and a pulse-width modulation control circuit configured to: generate an error signal based on the predetermined output voltage and a predetermined reference voltage, first to third voltages, a first triangular wave signal varying between the first and second voltages, and a second triangular wave signal varying between the third voltage and a fourth voltage, determined based on the first to third voltages, perform a comparison of the error signal with the first and second triangular wave signals, and cause the step-up and step-down circuit to step-up and step-down the input voltage based on a result of the comparison, wherein at least one of the first to third voltages is variably set such that a time period in which voltage ranges of the first and second triangular wave signals overlap is longer than a delay time period caused by the comparison.