POWER SUPPLY CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a power supply control circuit capable of preventing destruction of a semiconductor switch while controlling power supply according to an ON/OFF control signal.

SOLUTION: While paying attention to the fact that a falling timing of a source voltage Vs of an FET 20 caused by falling of a voltage level Vg of a PWM control signal S1 is delayed from a falling timing of the voltage level Vg, the source voltage Vs is compared with a reference value Vx in a detection timing within the delay time ts (off) and based on a result of the comparison, it is detected whether or not a thermal FET 11 is in a cutoff state.

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