Electrostatic discharge protective circuit having rise time detector and discharge sustaining circuitry

Abstract

Methods of the invention include an electrostatic discharge (ESD) protection method capable of detecting a slew rate of an input signal and capable of determining whether the slew rate of the input signal is greater than a threshold value. For an ESD event having a slew rate in excess of the threshold value said method generates a trigger signal which generates an activation signal that activates the ESD dissipation circuitry and that controls the length of time the dissipation circuit remains active. The method further comprises shunting the ESD energy away from a protected internal circuit. The method maintaining the shunting of the energy for a period of time sufficient to discharge of the ESD energy without damaging the protected circuitry.