Switching power circuit

A switching power circuit, comprising:

• a first switching transistor in which a main current path is connected between an input terminal to which a direct-current input voltage is applied and an output terminal supplying an output voltage;
• an inductor that is connected between the switching transistor and the output terminal;
• a first PWM signal generation circuit that generates a first PWM signal of which a duty ratio is changed in accordance with a first control voltage based on a control voltage output from a differential amplifier circuit comparing a reference voltage with a feedback voltage of the output voltage;
• a first rectification diode that is connected in a forward direction towards the first switching transistor from a ground;
• a second rectification diode that is connected in the forward direction towards the output terminal from the inductor;
• a second switching transistor that is connected between an anode of the second rectification diode and the ground;
• a second PWM signal generation circuit that generates a second PWM signal of which a duty ratio is changed in accordance with a second control voltage based on the control voltage, on a gate of the second switching transistor;
• and
• an overcurrent protection circuit that decreases a voltage of the reference voltage in a case where an output current of the first switching transistor is greater than a set current.