Patent ID: 7880234

Claim:
An electrostatic discharge protection circuit comprising: a metal-oxide semiconductor transistor having a first terminal being connected to an input end, and a gate being connected to a supply voltage; a first bipolar junction transistor having a first terminal being connected to the input end, and a base being connected to a second terminal of the metal-oxide semiconductor transistor; a second bipolar junction transistor having a first terminal being connected to the input end, a second terminal being connected to the supply voltage, and a base being connected to a second terminal of the first bipolar junction transistor; a first resistor having a first end being connected to the second terminal of the metal-oxide semiconductor transistor, and a second end being directly connected to the supply voltage without any intermediate components; and a second resistor having a first end being connected to the second terminal of the first bipolar junction transistor, and a second end being directly connected to the supply voltage and the second end of the first resistor without any intermediate components; wherein the input end is connected to an input pad from another circuit, and is not connected to a VDD.