Patent ID: 6313658
Filing Date: 2001-11-06
Classification: G01R

Abstract:
In an integrated circuit (IC) having an internal circuit and an external terminal for communications between the internal circuit and circuitry external to the IC, a device for isolating the internal circuit from the external communications terminal, the device comprising:short-sensing control circuitry for sensing a short in the internal circuit and outputting a control signal in response thereto, the short-sensing control circuitry comprising:a first PMOS transistor having a source coupled to a supply terminal, a gate coupled to an output terminal, and a drain coupled to a control signal terminal;a first resistive device coupled between the supply terminal and the output terminal;a second resistive device coupled between the control signal terminal and a reference voltage bond pad;a second PMOS transistor having a source coupled to the supply terminal, a gate, and a drain coupled to the control signal terminal; andan inverter coupled between the control signal terminal and the gate of the second PMOS transistor; andswitching circuitry coupled to the short-sensing control circuitry for isolating the internal circuit from the external communications terminal in response to receiving the control signal.