US Patent 11990747 Electrostatic protection circuit and semiconductor integrated circuit

An electrostatic protection circuit includes first and second output terminals, a first diode circuit connected between the first output terminal and a common node, a second diode circuit connected between the second output terminal and the common node, an intermediate voltage circuit that is connected between the first output terminal and the second output terminal and that is configured to generate, at the common node, an intermediate voltage having an intermediate voltage value between a voltage value of the first output terminal and a voltage value of the second output terminal, and a clamp circuit configured to electrically connect the common node to a ground line in accordance with the intermediate voltage.