| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply, wherein it is possible to detect reduction of increase in voltage applied to a driver for driving a transistor due to a bootstrap or prevent reduction in this increase. SOLUTION: A comparator 21 for an anomaly detection unit 20 compares the voltage of an SW node signal, indicating the voltage of the source of a transistor T1 that brings a direct-current power supply and an output unit 16 into either continuity or discontinuity with the voltage of the direct-current power supply 22. When the voltage of the SW node signal, that is, the voltage of one end of a capacitor C1 is equal to or higher than the voltage of the direct-current power supply 22, the comparator brings an SW node CMP signal as its output signal to the high level. When the SW node CMP signal is at a high level, during a period for which an SWMOS gate signal as the output of a driver 15 for driving the transistor T1 is at the low level, that is, during a period for which the driver 15 does not drive the transistor T1, an AND circuit 24 outputs an anomaly detection signal. COPYRIGHT: (C)2011,JPO&INPIT
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