Patent ID: 7280335

Claim:
A method for protecting a switch from a fault, comprising the steps of: sensing a low-side load current through the switch, wherein the switch includes a first terminal, a second terminal and a control terminal and the first terminal is connected to a low-side of a load and the second terminal is connected to ground, and wherein the switch provides a conductive path between the first and second terminals responsive to a control signal provided on the control terminal; reducing a magnitude of the control signal to limit the low-side load current carried by the switch when the low-side load current exceeds a first predetermined value; providing a resistive biasing network between the low-side of the load and ground; providing a second sense signal developed across at least a portion of the resistive biasing network to a control terminal of a second transistor, the second transistor including a first terminal and a second terminal, wherein the first terminal of the second transistor is coupled to the control terminal of the switch and the second terminal of the second transistor is coupled to ground; sensing a voltage at the low-side of the load; and pulling the control terminal of the switch to ground responsive to the second sense signal to interrupt the low-side load current when the second sense signal indicates that the voltage at the low-side of the load exceeds the second predetermined value.