Patent ID: 6958595

Claim:
A step-up/step-down DC-DC converter that yields an output voltage by stepping up or down an input voltage, comprising: an error signal generation circuit that generates an error signal commensurate with a difference between a voltage commensurate with the output voltage and a predetermined reference voltage; an inverting circuit that generates an inverted signal by inverting the error signal with respect to a predetermined inversion reference voltage; a triangular wave generation circuit that generates a triangular wave signal whose maximum level is higher than the predetermined inversion reference voltage and whose minimum level is lower than the predetermined inversion reference voltage; a first comparator that compares the error signal with the triangular wave signal; a second comparator that compares the inverted signal with the triangular wave signal; a step-up switching circuit that is turned on and off according to an output of the first comparator; a step-down switching circuit that is turned on and off according to an output of the second comparator; an inductor to and from which energy is accumulated and released as the step-up switching circuit and/or the step-down switching circuit is turned on and off; and a smoothing circuit that smoothes the output voltage by receiving the energy released from the inductor.