Patent ID: 7466527

Claim:
An electrostatic discharge (ESD) protection circuit comprising: a first LDNMOS transistor, having a drain served as an electrostatic input end, and a P-body and a source of the first LDNMOS transistor are connected to each other, wherein a coupling voltage signal determines whether the first LDNMOS transistor is turned on or not; a second LDNMOS transistor, having a drain connected to the drain of the first LDNMOS transistor, a P-body connected to the source of the first LDNMOS transistor, and a gate connected to a common ground potential; a first resistor, having one end connected to the source of the first LDNMOS transistor, and the other end connected to the common ground potential; and a gate driving resistor, having one end connected to the common ground potential, and the other end connected to the source of the second LDNMOS transistor, so as to generate the coupling voltage signal, and to couple the coupling voltage signal to the gate of the first LDNMOS transistor.