Patent ID: 8878508

Claim:
A control circuit of a DC-DC converter that includes a switching element, comprising: an error amplifier that amplifies a difference between a reference voltage and a feedback voltage corresponding to an output voltage of the DC-DC converter, and outputs the amplified difference; a voltage reduction comparator that outputs an interrupt signal when the feedback voltage is lower than a voltage reduction threshold that has a value lower than that of the reference voltage; and a pulse-width modulation (PWM) signal generator circuit that, when no interrupt signal is generated by said comparator, generates a PWM signal of a predetermined frequency based on the amplified voltage difference output by the error amplifier, and, when the interrupt signal is generated by said comparator, generates a switch drive signal to activate the switching element for a first period of time corresponding to the amplified voltage difference, and to deactivate the switching element for a second period of time after the first period of time has elapsed.