Patent ID: 7567091

Claim:
In an integrated circuit having an internal circuit and an external terminal for communications between the internal circuit and circuitry external to the integrated circuit, a device for isolating the internal circuit from the external communications terminal, the device comprising: control circuitry for sensing a short in the internal circuit and outputting a control signal in response thereto, the control circuitry comprising: a first transistor having a source connected to a supply terminal, a gate connected to an output terminal, and a drain connected to a control signal terminal; a first resistor connected between the supply terminal and the output terminal; a second resistor connected between the control signal terminal and a reference voltage bond pad; a second transistor having a source connected to the supply terminal, a gate, and a drain connected to the control signal terminal; an inverter connected between the control signal terminal and the gate of the second transistor; and switching circuitry coupled to the control circuitry for isolating the internal circuit from the external communications terminal in response to receiving the control signal.