Patent ID: 8553380

Claim:
An apparatus comprising: a substrate having a first well disposed in the substrate, wherein the first well has a doping of a first type, wherein the substrate has a second well adjacent the first well, wherein the second well has a doping of a second type opposite to that of the first type; a first active area disposed in the first well, wherein the first active area has a doping of the first type; a second active area disposed in the first well, wherein the second active area has a doping of the second type; and wherein the second active area, the first well, and the second well are configured to operate as an emitter, a base, and a collector of a bipolar transistor, respectively, and wherein the second active area surrounds at least a portion of the first active area so as to aid in recombining carriers injected into the first well from the second well before the carriers reach the first active area; wherein the first well and the second well are configured to operate as a breakdown diode, and wherein a punch-through induced breakdown voltage between the second well and the first well is lower than or equal to about a direct breakdown voltage between the second well and the first well; wherein the apparatus is configured to provide protection from a transient electrical event.