| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching circuit that does not apply a voltage to a load even in a case where surplus voltage is emitted from an FET driver.SOLUTION: A switching circuit comprises: a control circuit that connects to a first positive constant voltage power source and generates a control signal from an input signal; an FET driver having a protection diode connecting a signal input terminal and a power source supply terminal and configured to connect to a second positive constant voltage power source via a protection circuit; a P type Power MOS FET in which a drain terminal is connected to the second constant voltage power source via the projection circuit, a gate terminal is connected to the second positive constant voltage power source via the protection circuit and resistance, and a source terminal is connected to a load; and a reverse current blocking part that allows the passage of a current flowing from the second positive constant voltage power source to the power source terminal of the FET driver and that blocks current flowing from the power source terminal of the FET driver to the drain terminal and gate terminal of the P type Power MOS FET. |
