| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching regulator having an overcurrent protection function. SOLUTION: An error amplifier 10 compares the output voltage Vout of the switching regulator 200 with a predetermined reference voltage Vref1 and generates an error signal Verr based on the difference between the two voltages. A comparator 14 compares a detection signal Vdet' based on a coil current passed through the output inductor L1 of the switching regulator 200 with the error signal Verr from the error amplifier 10 and outputs an off signal Soff that is brought to the high level when the value of the detection signal Vdet' reaches the value of the error signal Verr. A driver circuit 30 turns off a switching transistor M1 when the off signal Soff is brought to the high level and turns on the switching transistor M1 when a clock signal CK transitions to the high level. A clamp circuit 50 clamps the error signal Verr output from the error amplifier 10 at a clamp value based on the output voltage Vout of the switching regulator 200. COPYRIGHT: (C)2009,JPO&INPIT
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