A DC-DC converter includes a smoothing capacitor connected between a first output terminal connected to a first end of a load and a second output terminal connected to a second end of the load, the smoothing capacitor smoothing an output voltage. The DC-DC converter includes a choke coil having a first end connected to a first end of a battery. The DC-DC converter includes a semiconductor integrated circuit having a switch terminal connected to a second end of the choke coil, a first potential terminal connected to the first output terminal, and a second potential terminal connected to the second output terminal and a second end of the battery.