Abstract: This invention provides a power switch circuit and a power circuit using the power switch circuit. In particular, the power switch circuit includes a first reverse current monitoring circuit and a second reverse current monitoring circuit. The first reverse current monitoring circuit is coupled to a power transistor, and is configured to detect whether a reverse current flows through the power transistor to a voltage input terminal for a predetermined period of time, and only if yes, turn off the power transistor. The second reverse current monitoring circuit is coupled to the power transistor, and is configured to detect whether a reverse current flows through the power transistor to the voltage input terminal, and if yes, turn off the power transistor immediately.

Abstract: This invention provides a power switch circuit and a power circuit using the power switch circuit. In particular, the power switch circuit includes a first reverse current monitoring circuit and a second reverse current monitoring circuit. The first reverse current monitoring circuit is coupled to a power transistor, and is configured to detect whether a reverse current flows through the power transistor to a voltage input terminal for a predetermined period of time, and only if yes, turn off the power transistor. The second reverse current monitoring circuit is coupled to the power transistor, and is configured to detect whether a reverse current flows through the power transistor to the voltage input terminal, and if yes, turn off the power transistor immediately. As such, the reverse current can be blocked in time from further flowing to the voltage input terminal, thereby avoiding a damage to the interior electronic components of the power source at the low voltage side.