Patent ID: 7612545

Claim:
A DC/DC converter for, through the opening and closing of a switching element, supplying power from an input power supply, via a coil, to an output terminal connected to a load, and adjusting a voltage of the output terminal, the DC/DC converter comprising: a coil current detection element interposed between the coil and the output terminal, and arranged to generate, in a terminal connected to the coil and a terminal connected to the output terminal, a detection voltage in response to a coil current; a smoothing capacitor connected to the load side of the coil current detection element to smooth the voltage of the output terminal; a reference current value control circuit arranged to detect the voltage of the coil side of the coil current detection element and to control a reference current value of a current flowing in the coil; and a feedback circuit having an offset voltage generator arranged to generate an offset voltage that corresponds to the reference current value in response to an output voltage of the reference current value control circuit, and arranged to close the switching element in synchronization with a reference clock signal of a clock signal generator, and open the switching element in response to comparing the detection voltage with the offset voltage when the current flowing in the coil exceeds the reference current value.