POWER SUPPLY DEVICE

摘要

Control signals, which control a MOSFET (Q1) of a power supply device (10) to be in an ON status and a MOSFET (Q2) of the power supply device to be in an OFF status, are given to gates of the MOSFETs (Q1, Q2) from a control circuit (11) during a standby time, respectively. An emitter of a pnp transistor (Q3) is connected to the gate of the MOSFET (Q2) through a diode (D6) of a switch circuit (1), and a collector is connected to the ground. A power supply operation control signal is inputted to a base of the pnp transistor (Q3), and when the power supply operation control signal in a Low status is inputted to the base during the standby time, an electricity is carried between the emitter and the collector. Thus, the gate of the MOSFET (Q2) is permitted to have a substantially a ground potential, and the MOSFET (Q2) is permitted to be in the OFF-status, not depending on the control signal.