US Patent 7586720 Electrostatic discharge protection device

A compact ESD protection device is described that uses the reverse breakdown voltage of a base-emitter junction as a trigger diode to switch a transistor that shunts the forward bias ESD current to ground. The trigger diode in series with a leakage diode provides a path to shunt the reverse bias ESD current to ground. The leakage diode is matched to the trigger diode to shunt any leakage current from the trigger diode to ground.