Overheat protection circuit and switching regulator including the same

An overheat protection circuit, comprising:

• an input terminal;
• an output terminal;
• a first transistor which includes a first terminal to be supplied with a reference voltage, and a second terminal to be connected to a ground terminal, a control terminal, and which is configured to be switchable between an on state and an off state in accordance with a voltage level of an input voltage applied at the input terminal;
• and
• a first NPN transistor which includes a base to be connected to a node between the second terminal of the first transistor and the ground terminal, an emitter to be connected to the ground terminal, and a collector to be supplied with a constant current and connected to the output terminal, the first NPN transistor having a temperature coefficient of zero or more, and being switchable between an on state and an off state in accordance with a voltage level of a reference voltage to be supplied to the base.