Switching control circuit and self-excited DC-DC converter

摘要

The switching control circuit comprises a switching control signal generation circuit that detects a change in ripples of the output voltage and-generates a switching control signal for the on/off control of the switching element to make the output voltage follow the target level; an overcurrent state detection circuit that generates a state signal indicating whether the output current is in an overcurrent state where the output current is equal to or greater than a predetermined current; and a delay circuit that delays the state signal for a same predetermined delay time at both of the times when the output current exceeds the predetermined current and when the output current falls below the predetermined current.