Patent ID: 8541838

Claim:
A monolithically-integrated dual surge protective device, comprising: a) a Laterally Diffused Metal Oxide Semiconductor (LDMOS) device, and a diode assembly which comprises multiple diodes series-wound on back to back basis in the following sequence: N-P- . . . -N-P-N-P-N- . . . -P-N-; b) one end of the diode assembly being connected to a drain electrode of the LDMOS device and the other end is connected to a gate electrode of the LDMOS device; c) the breakdown voltage of the diode assembly being selected below the breakdown voltage of the semiconductor device, so that, when a surge voltage in excess of the breakdown voltage of the LDMOS device occurs, the diode assembly breaks down to protect the LDMOS device; and d) the diode assembly being arranged so that current through said assembly can flow through a resistance between the gate electrode and a source electrode of the LDMOS device and cause a voltage drop across said resistance that exceeds the threshold voltage of the LDMOS device, so as to cause break-over of the LDMOS device with resulting current being broken over from the drain electrode to the source electrode, so as to further protect the LDMOS device.