Patent ID: 8189309

Claim:
An apparatus comprising: a first terminal; a second terminal; a first transistor having a first passive electrode, a second passive electrode, and a control electrode, wherein the first passive electrode of the first transistor is coupled to the second terminal; a first resistive element that is coupled to the second terminal; a first diode stack that is coupled to the first resistive element, wherein the first diode stack has a first breakdown voltage; a second diode stack that is coupled between the first diode stack and the control electrode of the first transistor, wherein the second diode stack has a second breakdown voltage; a second resistive element that is coupled between the first terminal and a node between the first and second diode stacks; and a second transistor having a first passive electrode, a second passive electrode, and a control electrode, wherein the first passive electrode of the second transistor is coupled to the node between the first and second diode stacks, and wherein the control electrode of the second transistor is coupled to the first terminal, and wherein the second passive electrode of the second transistor is coupled to the control electrode of the first transistor.