ELECTROSTATIC DISCHARGE PROTECTION CIRCUIT

摘要

An electrical circuit including an NMOS (20) or lateral NPN bipolar transistor (136) includes a zener diode (28) connected thereto to provide ESD protection for the transistor. The NMOS transistor (20) includes an N-type source (22), an N-type drain (24), a p-type channel region and a gate (26) over and insulated from the channel region. The zener diode (28) is electrically connected between the gate (26) and the drain (24) of the NMOS transistor (20) with the anode (30) of the zener diode (28) being connected to the gate (26) and the cathode (32) of the zener diode (28) being connected to the drain. For some purposes the anode (30) of the zener diode (28) is positioned close to the gate (26) to provide the desired ESD protection. The lateral NPN bipolar transistor (136) includes an N-type emitter (138) and collector (140) and a P-type base (142). The zener diode (144) is connected between the collector (140) and the base (142) with the anode (146) of the zener diode (144) being connected to the base (142) and the cathode (148) of the zener diode (144) being connected to the collector (140).