Patent ID: 8466489

Claim:
An apparatus for providing protection from transient electrical events, the apparatus comprising a protection device which includes: a substrate; a central well disposed in the substrate, wherein the central well has a doping of a first type; a first well disposed in the substrate adjacent to the central well, wherein the first well has a doping of a second type opposite to the first type; a second well disposed in the substrate adjacent to the central well and opposite side of the central well from the first well, wherein the second well has a doping of the second type; a first active region and a second active region disposed in the first well, the second active region having a portion farther from the central well than at least a portion of the first active region, the first active region having a doping of the first type, the second active region having a doping of the second type; a third active region and a fourth active region disposed in the second well, the fourth active region having a portion farther from the central well than at least a portion of the third active region, the third active region having a doping of the first type, the fourth active region having a doping of the second type; wherein the central well, the first well, and the second well are configured to operate as a bi-directional bipolar device having an emitter/collector, a base, and a collector/emitter; wherein the first active region, the second active region, the first well, and the central well are configured to operate as a first bipolar transistor having an emitter, a base, and a collector; wherein the third active region, the fourth active region, the second well, and the central well are configured to operate as a second bipolar transistor having an emitter, a base, and a collector.