Patent ID: 7714560

Claim:
A control circuit which turns on/off switching device elements of a synchronous rectifier switching regulator, comprising: a hysteresis comparator which compares a detection voltage that corresponds to an output voltage of said step-down switching regulator with a first threshold voltage and a second threshold voltage which is lower than the first threshold voltage; a light-load detection circuit which detects whether or not a load connected to said step-down switching regulator is in the light-load state; and a driver circuit which turns on/off said switching device elements according to a pulse signal output from said hysteresis comparator, wherein, upon said light-load detection circuit detecting the light-load state, said hysteresis comparator shifts the second threshold voltage toward a higher voltage side by a predetermined voltage difference, and wherein, after said light-load detection circuit detects the light-load state, said driver circuit stops the ON/OFF operation of said switching device elements during a period from the time point at which the detection voltage rises up to the first threshold voltage to the time point at which the detection voltage drops to the second threshold voltage thus shifted.