| 摘要 |
PROBLEM TO BE SOLVED: To obtain a synchronous rectification type switching regulator which can shorten a delay time of a backflow detection circuit, can largely reduce current consumption, and can improve efficiency. SOLUTION: A proportional voltage Vs1 proportional to a voltage VLx of a connecting part Lx to which a synchronous rectifying transistor S2 and an inductor L1 are connected is generated at a proportional voltage generation circuit 11, and a comparator 13 compares the proportional voltage Vs1 and a prescribed second reference voltage Vref2, and outputs a signal Vdet of a high level when the proportional voltage Vs1 reaches a value not lower than the second reference voltage Vref2, and when there is detected a sign that a reverse current is generated, or the generation of the reverse current. Accompanied by this, a control circuit 6 brings the synchronous rectifying transistor S2 into a blocked state by turning it off irrespective of an input PWM-pulse signal Spwm. COPYRIGHT: (C)2009,JPO&INPIT
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