Switching power supply with short circuit detection

A switching power supply, comprising:

• a switching device connected in series to an inductance element and arranged between an input power supply and a ground terminal;
• an output circuit that rectifies and smooths current output through the inductance element from the input power supply as the switching device is switched ON and OFF;
• an output voltage control circuit that controls an ON time of the switching device on the basis of an error voltage between a prescribed reference voltage and a feedback voltage obtained by detecting an output voltage of the output circuit;
• and
• a short-circuit detection circuit that detects a voltage applied to a control terminal of the switching device when the switching device is ON, determines that a short-circuit has occurred in the switching device if the voltage becomes less than a prescribed threshold value, and outputs a short-circuit detection signal to control operation of the output voltage control circuit so as to reduce the ON time of the switching device to be less than the ON time of the switching device when there is no short-circuit,
• wherein the switching device is an n-type MOSFET, and
• wherein the short-circuit detection circuit detects a voltage between a source and gate of the n-type MOSFET when the n-type MOSFET is switched ON by the output voltage control circuit.