The present invention has: a pump capacitor (12), which has one end thereof connected to the source power supply (B) side via a diode (7), and which has the other end thereof connected to two kinds of voltage sources via switches (3, 4); and an output capacitor (13), which has one end there of connected to a high-potential terminal of a pump capacitor via a diode (8), and the other end thereof connected to a source power supply. A filter circuit configured with a resistor (15) and a capacitor (11) is provided between the source power supply and the diode (7).