| 摘要 |
PROBLEM TO BE SOLVED: To mask a current spike caused by the turning-on/off of a power transistor by a simple constitution. SOLUTION: This power supply circuit feeds an output voltage corresponding to an input voltage to a load by on/off-controlling the power transistor. The power transistor is turned on/off by a drive signal, the power supply circuit is provided with an LEB circuit 20 and a comparator 21, and the comparator obtains a comparison result signal by comparing a gate voltage of the power transistor and a prescribed threshold voltage. The LEB circuit 20 comprises delay circuits 22, 23, 24 and 26 each of which generates a delay signal by delaying the drive signal for a prescribed time, and an NOR gate 25 that obtains a reference signal for generating the drive signal according to the delay signal and the comparison result signal, and masks the rising zone of the gate voltage according to the reference signal for a prescribed time. COPYRIGHT: (C)2008,JPO&INPIT
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