Disclosed is a power supply for receiving an input voltage and generating an output voltage and an output current, which includes a power converter for receiving the input voltage and generating an intermediate output voltage, an output protection circuit connected to an output terminal of the power converter and including a plurality of switch circuits connected in parallel with each other. The output protection circuit is configured to limit the flowing direction of the output current by the switching operations of the switch circuits. The power supply further includes a control unit connected to the output protection circuit for issuing a plurality of control signals to the switch circuits, in which at least two of the control signals are set to allow at least two of the switch circuits to be turned off with different timings.