Patent ID: 10236684

Abstract:
An ESD protection circuit has a diode that includes an anode connected to a first power-supply line and a cathode connected to a second power-supply line. A metal-oxide-semiconductor (MOS) transistor is connected in series with the diode. A trigger circuit is configured to output a trigger signal to a gate of the MOS transistor in synchronization with a surge on the first power-supply line. A first resistor and a first capacitor are connected in series between the first power-supply line and the second power-supply line. A well region, in which the source and the drain of the MOS transistor are disposed, is connected to a connection point between the first resistor and the first capacitor. A potential of the connection point varies so that a forward voltage is applied to a p-n junction between the well region and the source of the MOS transistor to correspond with the surge.