| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply control circuit which varies and controls the level of a source voltage to a load device according to a trigger signal in the form of not software constitution whose specification alternations are complicated, but hardware constitution, and to prevent the power supply control circuit from malfunctioning. SOLUTION: The trigger signal 5 is supplied to a PNP transistor 12 of an initial-stage inverter to be inverted in level and the output level thereof is supplied to an NPN transistor 14 of a next-stage inverter to be further inverted in level. The output thereof is used as an on/off signal for a P-channel FET 6. A voltage equal to the high level of the trigger signal 5 is used as the power source of the initial-stage inverter, and the source voltage of a power source 1 is used as the power source of the next-stage inverter. Consequently, the level of the trigger signal 5 is securely converted to a level which is high enough to perform on/off control over the FET 6. COPYRIGHT: (C)2008,JPO&INPIT
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