OVERCURRENT PROTECTION CIRCUIT AND SWITCHING POWER SUPPLY EMPLOYING THE SAME

摘要

PROBLEM TO BE SOLVED: To perform an appropriate overcurrent protection operation.SOLUTION: An overcurrent protection circuit 13 comprises: a voltage monitoring part (comparator 131) for monitoring an output voltage VOUT produced by a cyclic switching operation of a switching output stage 11 or a feedback voltage VFB corresponding to the output voltage; a current monitoring part (a comparator 132 and a sense resistor 133) for monitoring whether a monitoring object current IS flowing in the switching output stage 11 is in an overcurrent state; and a protection operation part (a signal delay part 134 and signal path switching parts 135a and 135b) for performing the overcurrent protection operation corresponding to detection results (detection signals DET1 and DET2) of both the voltage monitoring part and the current monitoring part.SELECTED DRAWING: Figure 1