Patent ID: 7498785

Claim:
A step-down switching regulator configured to convert a voltage input to an input terminal into a set voltage and output the converted voltage from an output terminal, the step-down switching regulator comprising: a first switching element configured to switch in accordance with a first control signal input to a control electrode thereof so as to perform output control of the input voltage; an inductor connected between an output end of the first switching element and the output terminal; a second switching element configured to release energy stored in the inductor in accordance with a second control signal input to a control electrode thereof; and an interruption circuit configured to interrupt a backflow of current from said inductor to said second switching element, by turning off the second switching element, wherein said interruption circuit includes a detector circuit part configured in detect a reverse current flowing from the inductor to the second switching element, and detect a change in the set voltage, and wherein said interruption circuit causes the second switching element to be turned off upon detection of the reverse current, and when said detector circuit part detects said change in the set voltage, said interruption circuit does not turn off the second switching element due to detection of reverse current for a predetermined period of time, and after the predetermined period is over, said interruption circuit resumes turning off the second switching element upon detection of the reverse current.