Patent ID: 9263884
Filing Date: 2016-02-16
CPC Classification: H02H

Claim Text:
1. An electrostatic protection circuit, comprising: a trigger circuit connected between a first power source line and a second power source line and configured to output a trigger signal in response to a voltage difference between the first and second power source lines; a buffer circuit configured to output a drive signal in response to the trigger signal; a switch circuit having a main current path connected between the first power source line and the second power source line, and configured to switch a conduction state of the main current path between an ON state and an OFF state in accordance with the drive signal, the switch circuit including a first transistor having a source-drain path connected between the first power source line and the second power source line; and a control circuit configured to supply a control signal to the switch circuit in response to the drive signal to cause the switch circuit to switch the conduction state of the main current path to the ON state, the control signal maintaining the conduction state of the main current path in the ON state while the voltage difference between the first and second power source lines exceeds a predetermined value, the control circuit including: the drive signal is supplied to a gate electrode of the first transistor and the gate electrode of the second transistor, and an output of the current mirror circuit is supplied to the gate electrode of the first transistor.