| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit wherein current property after detecting excess current can be made foldback current limiting characteristic without adding an error amplifier for excess current protection controlling in a switching power supply. SOLUTION: In the switching power supply having the error amplifier OP2 for stabilizing an output voltage, potential dividing resistances R4 and R5 different from potential dividing resistances R2 and R3 for voltage control and resistance R9 connected between the middle point of the resistances R4 and R5 and a collector of a transistor Q2 are arranged. As a result, foldback current limiting characteristic is realized by only the error amplifier for fixed voltage controlling without using an error amplifier for excess current controlling. COPYRIGHT: (C)2004,JPO&NCIPI
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