Patent ID: 8610251

Claim:
A protection device for providing protection from transient electrical events, the apparatus comprising: a first n-type well region; a second n-type well region; a first p-type well region disposed between the first and second n-type well regions, wherein the first n-type well region, the first p-type well region, and the second n-type well region are configured as an NPN bi-directional bipolar transistor; a p-type tub configured to surround the first p-type well region and the first and second n-type well regions, wherein the p-type tub comprises a plurality of sides and a bottom, wherein the bottom extends beneath the first n-type well region, the second n-type well region, and the first p-type well region, and wherein the a bottom of the first-p-type well region is in contact with the p-type tub; an n-type tub configured to surround the plurality of sides and the bottom of the p-type tub, wherein the bottom comprises an end of the p-type tub opposite a surface of the protection device; a first p-type active region disposed in the first n-type well region, wherein the first p-type active region, the first n-type well region, and the p-type tub are configured as a first PNP bipolar transistor; a second p-type active region disposed in the second n-type well region, wherein the second p-type active region, the second n-type well region, and the p-type tub are configured as a second PNP bipolar transistor; a first pad configured to receive a first voltage; a second pad separate from the first pad configured to receive a second voltage different from the first voltage; a first n-type active region disposed in the first n-type well region, wherein the first pad is electrically connected to the first n-type active region; and a second n-type active region disposed in the second n-type well region, wherein the second pad is electrically connected to the second n-type active region.