Patent ID: 7479773

Claim:
A synchronous rectification switching regulator, comprising: an input terminal configured to receive an input voltage; an output terminal configured to output a predetermined output voltage obtained by converting the input voltage; a load connected to the output terminal and configured to receive the predetermined output voltage output by the output terminal; a first switching element configured to perform a first switching; an inductor charged with the input voltage by the first switching of the first switching element; a second switching element for synchronous rectification configured to perform a second switching to discharge the inductor; a control circuit unit configured to control the first switching element to perform the first switching and to control the second switching element to perform the second switching opposite to the first switching, causing the output terminal to output the predetermined output voltage; a reverse current prevention circuit unit including a third switching element connected to the second switching element in series; and a connecting portion configured to connect the second switching element with the third switching element, wherein the reverse current prevention circuit unit detects one of a symptom of a reverse current flowing in a direction from the output terminal to the second switching element and a generation of the reverse current based on a voltage of the connecting portion, and wherein the reverse current prevention circuit unit turns off the third switching element to interrupt the reverse current when the reverse current prevention circuit unit detects the symptom or the generation of the reverse current.