A control circuit for controlling an output voltage of a DC/DC converter. The control circuit includes a pulse signal generation circuit which generates a pulse signal for controlling the output voltage of the DC/DC converter, and a drive signal generation circuit which generates first and second drive signals using the pulse signal such that a main switching element and a synchronous switching element are turned ON and OFF alternately at different timings. The drive signal generation circuit generates the first drive signal which has substantially the same pulse width as that of the pulse signal to improve ON-duty characteristics of the main switching element.