Patent ID: 8193560

Claim:
An electronic device having a first terminal and a second terminal, comprising: a circuit core coupled between the first terminal and the second terminal; and at least one voltage limiting device coupled between the first terminal and the second terminal, wherein the voltage limiting device comprises: a first bipolar transistor having an emitter of a first conductivity type, a first base of a second opposite conductivity type and a first base width, and a first collector of the first conductivity type; and a second bipolar transistor having a second emitter of the second conductivity type, a first portion of a second base of the first conductivity type and having a second base width and a first doping density, a further portion of the second base within the first portion of the second base and having the first conductivity type and a second doping density higher than the first doping density, and a second collector of the second conductivity type; a first base resistance coupled between the first emitter and the first base; a second base resistance coupled between the second emitter and the second base; and wherein a PN junction exits between the first base and the second base; and wherein the first emitter is coupled to the second terminal and the second emitter is coupled to the first terminal.