Patent ID: 7940507
Filing Date: 2011-05-10
Classification: H02M,Y02B

Abstract:
1. A switching control circuit that is provided in a self-excited DC-DC converter chopping a direct-current input voltage by turning on/off a switching element and then smoothing the chopped voltage with a smoothing circuit to generate an output voltage of a target level that is different from a level of the input voltage, the switching control circuit comprising: 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, wherein the delayed state signal is output