Texas Instruments Incorporated
Turn off circuit for protection switch

Abstract:

A switch circuit includes: a power transistor having a source coupled to a supply terminal, a drain coupled to an output terminal, and a gate; a bipolar transistor having a collector coupled to the supply terminal, an emitter coupled to the gate of the power transistor, and a base; a bias circuit to control an emitter current of the bipolar transistor; and a resistor coupled between the supply terminal and the base. A control circuit receives a current at a current input to turn the bipolar transistor on responsive to a control input being in a first state, and ceases receiving the current at the current input to reduce a gate-source voltage of the power transistor responsive to the control input being in a different second state.