Patent ID: 8659274

Claim:
A switching power supply circuit in a synchronous rectification mode for alternately turning on and off a main switching element and a subordinate switching element to convert a direct current input voltage into a direct current output voltage, comprising: a differential amplification stage for outputting an error signal representing a difference voltage between a preset reference voltage and a voltage based on the output voltage; an ON-time generation circuit for defining a period of time during which the main switching element is kept ON; a flip-flop circuit which is set by a set signal based on the error signal and reset by a reset signal being an output of the ON-time generation circuit; current information means for detecting current information representing a current flowing to the subordinate switching element; current information detecting means for supplying a current information detecting signal, which makes an adjustment based on the current information so as to delay a timing of a rise of the set signal, to an output side or an interior of the differential amplification stage; and current information holding means for holding the current information detected by the current information means at a moment when the subordinate switching element is turned on, and supplying a current information holding signal, which makes an adjustment so as to advance the timing of the rise of the set signal, to the output side or the interior of the differential amplification stage.