Patent ID: 7079369

Claim:
An electronic computer controlled system selected from the group consisting of communication, networking, routing, or server/client systems having computer processing electronics, keyboard and display, memory, input/output controllers and devices, the electronic computer controlled system further comprising: a power supply providing power to a power rail with respect to a ground rail, and where an ESD voltage appears as an increasing or decreasing voltage between the power and ground rails, electronic circuits powered from the power and ground rails, a first active ESD protective device disposed between the power and the ground rails that limits the ESD voltage, the active ESD device having a first control node, a second active device having a second control node, a third active device functionally connected between the second control node and the power rail, a capacitor functionally connected between the second control node and the ground rail, wherein, when a positive ESD voltage appears on the power rail, capacitor voltage trails the ESD voltage by an amount wherein the second active device turns on and drives the first active device into a snap-back condition and turns on a parasitic bipolar transistor within the first ESD active device, wherein the first ESD active device limits the ESD voltage on the power rail, and wherein the rising ESD voltage also turns on the third active device to start charging the capacitor such that the voltage on the capacitor rises and turns off the second active device after a designed time delay, and that discharges the capacitor when the ESD voltage is falling.