Patent ID: 7911749

Claim:
An electrostatic discharge (ESD) protection device, comprising: an adjusting circuit, which comprises: a silicon controlled rectifier (SCR) comprising a first diode, wherein the first diode comprises a P region coupled to a pad and an N region; a snapback element coupled to the N region of the first diode, wherein the snapback element is coupled to the pad through the first diode; a diode circuit, coupled between the first diode and the snapback element; and a control circuit, which is coupled to the N region of the first diode, provides a first voltage to the N region of the first diode in a normal operation mode so that the SCR is turned off, and does not provide the first voltage to the N region of the first diode in an ESD mode so that a current flows from the pad to the snapback element through the first diode and the diode circuit to trigger the snapback element, and the SCR is turned on to discharge electrostatic charges on the pad through the SCR.