| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply voltage circuit capable of reducing power consumption while achieving the good characteristics of an overcurrent protection circuit. SOLUTION: The power supply voltage circuit includes an output transistor M1 for allowing a first current I1 to flow into an output terminal Po on the basis of a control voltage input to a control terminal and output from an error amplifier 2, a reference transistor M2 for allowing a second current I2 corresponding to the first current I1 to flow into the output terminal Po and the overcurrent protection circuit for adjusting the potential of a control voltage on the basis of the comparison of a detection voltage generated on the basis of the second current I2 with a reference voltage. The flow of an overcurrent into the output transistor M1 is detected on the basis of the comparison of the detection voltage with the reference voltage. Consequently the time when an overcurrent is allowed to flow can be more accurately detected. Further, since the first current I1 and the second current I2 are allowed to flow into the output terminal Po, the amount of current consumed in the power supply voltage circuit is reduced. COPYRIGHT: (C)2008,JPO&INPIT
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