Patent ID: 7538998

Claim:
An electrostatic discharge (ESD) protection circuit, comprising: a pad; a first transistor having the gate, a first source-drain, a second source-drain, and a bulk substrate, wherein the first source-drain is electrically coupled to the pad, and the second source-drain and the bulk substrate are electrically coupled to a first power line; a resistance element having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the gate of the first transistor, and the second terminal is electrically coupled to the first power line; and a diode having a first terminal and a second terminal, wherein the first terminal is directly coupled to the gate of the first transistor, and the second terminal is directly coupled to the pad; wherein the first transistor is an N-type metallic oxide semiconductor field effect transistor (MOSFET) as well as the first terminal of the diode is an anode and the second terminal of the diode is a cathode; wherein the diode and the first transistor together form a silicon controlled rectifier (SCR).