Patent ID: 8737028
Filing Date: 2014-05-27
Classification: H02H

Abstract:
1. A method of responding to an electrostatic discharge (ESD) event, the method comprising: in response to the ESD event on a first voltage rail, generating a trigger signal with an RC network having a time constant equal to a product of a resistance of a field-effect transistor and a capacitance of a capacitor coupled in series with the field effect transistor between the first voltage rail and a second voltage rail; providing the trigger signal from the RC network to an inverter; driving a clamp device with the inverter to discharge current from the ESD event from the voltage rail through the clamp device; and after the trigger signal is provided from the RC network to the inverter, providing a feedback signal from an output of the inverter to a gate of the field-effect transistor to increase the resistance of the field-effect transistor such that the time constant of the RC network is increased to sustain the discharge of the current by the clamp device.