Abstract: In a switching circuit comprising an output field effect transistor having an output drain electrode connected to a power supply through a load resistor and an output gate electrode supplied with an input voltage, a reference field effect transistor has a reference drain electrode connected to the power supply through a reference resistor and a reference gate electrode supplied with the input voltage. Each of the output and the reference field effect transistors is made of a metal oxide semiconductor. A comparator has a load input terminal connected to a load node of the output drain electrode and the load resistor and a reference input terminal connected to a reference node of the reference drain electrode and the reference resistor. The comparator compares a load sensing voltage from the load node with a reference voltage from the reference node to produce a compare output voltage when the load sensing voltage is higher than the reference voltage.