Protection circuit with a FET device coupled from a protected bus to ground

A semiconductor device, comprising:

• a circuit node;
• a ground voltage node;
• a first transistor coupled between the circuit node and the ground voltage node, wherein the first transistor is a field-effect transistor (FET);
• a second transistor coupled between the circuit node and the ground voltage node in parallel with the first transistor, wherein the second transistor is a FET, and wherein a source or drain terminal of the second transistor is coupled to a gate terminal of the first transistor;
• a resistor coupled between the gate terminal of the first transistor and the ground voltage node;
• a voltage-limiting circuit coupled between the gate terminal of the first transistor and the ground voltage node in parallel to the resistor;
• and
• a triggering circuit comprising an input coupled to the circuit node and an output of the triggering circuit coupled to a gate terminal of the second transistor, wherein the triggering circuit further includes a third transistor comprising an emitter or collector terminal coupled to the gate terminal of the second transistor, and wherein the third transistor is a bipolar junction transistor (BJT).

A method of electrical-overstress protection, comprising:

• providing an electrical device comprising a circuit node and a ground node;
• providing a first transistor electrically coupled between the circuit node and ground node, wherein the first transistor is a field-effect transistor (FET);
• providing a second transistor electrically coupled between the circuit node and a gate terminal of the first transistor, wherein the second transistor is a FET;
• providing a voltage-limiting circuit coupled between the gate terminal of the first transistor and the ground node;
• and
• providing a triggering circuit comprising an input coupled to the circuit node and an output of the triggering circuit coupled to a gate terminal of the second transistor, wherein the triggering circuit includes a bipolar junction transistor (BJT) comprising an emitter or collector terminal of the bipolar junction transistor coupled to the circuit node.