A control circuit of a power supply that generates an output voltage from an input voltage includes a gain adjustment circuit that adjusts a gain of an alternating-current component of the output voltage. An addition circuit adds an output signal of the gain adjustment circuit to a first feedback voltage, which is in accordance with the output voltage, to generate a second feedback voltage. A voltage generation circuit generates a comparison reference voltage that changes at a given rate with respect to a first reference voltage that is set according to a target value of the output voltage. A switch control circuit controls the output voltage by switching a switch circuit, to which the input voltage is supplied, at a timing according to a result of a comparison of the second feedback voltage with the comparison reference voltage.