Switching control circuit and switching power supply device

A switching control circuit for use in a power conversion circuit in a switching power supply device and includes a semiconductor integrated circuit to control a switching element, the switching control circuit comprising:

• a plurality of external terminals including a feedback signal input terminal arranged to receive a feedback signal that is generated by the power conversion circuit in response to an operation of the switching control circuit;
• an output voltage stabilization control unit configured to control stabilization of an output voltage in accordance with a signal input into the feedback signal input terminal;
• and
• a protected operation mode setting unit configured to detect a voltage induced by an external circuit that is connected to the feedback signal input terminal and that includes a resistor element or a semiconductor element, as a determination target signal, and to set one of a hiccup mode in which an oscillation period and a suspension period are repeated and a latch mode in which oscillation is stopped in accordance with the determination target signal in an overload state or an overvoltage output state;
• wherein
• the feedback signal input terminal is defined by a single one of the plurality of external terminals;
• and
• the feedback signal input terminal is arranged to control the output voltage stabilization control unit so as to control stabilization of the output voltage and to control the protected operation mode setting unit so as to select one of the hiccup mode and the latch mode.