Patent ID: 7087968

Claim:
An electrostatic discharge protection circuit adapted for an integrated circuit with a first power source and a second power source, the protection circuit comprising: a first silicon controlled rectifier, comprising a first metal-oxide-semiconductor transistor, wherein a cathode of the first silicon controlled rectifier is coupled to the first power source, and an anode of the first silicon controlled rectifier is coupled to the second power source; a second silicon controlled rectifier, comprising a second metal-oxide-semiconductor transistor, wherein an anode of the second silicon controlled rectifier is coupled to the first power source, a cathode of the second silicon controlled rectifier is coupled to the second power source, and gates of the first and the second metal-oxide-semiconductor transistors are coupled to the first power source or the second power source; and a parasitic diode, wherein a cathode of the parasitic diode is coupled to the first power source, and an anode of the parasitic diode is coupled to the second power source.