Prolongation of Double RLC Model for ESD Manifold Events

摘要

The starting point of our work was focused around some phenomena encountered while testing the ESD immunity of vehicle electrical equipment, mainly using a laptop, an ESD gun and a scope. One target of our approach is to find explanations for the influence of the position of the ground connection of the ESD tester and of the rod geometry and dimension upon the rise time of the injected current into the abovementioned laptop. The scope was a good 500MHz one, with connectivity facilities, inserted in an experimental set-up recommended by IEC. The second target was to extend a model and to set its lumped elements for multiple discharges. We observed during some ESD events, successive pulses, with a decreasing energy level, being separated by a time period lasting tens of milliseconds. We consider that this multiple discharge event could by modelled by up-grading the body metallic model. Scope-tracing many ESD discharge waveforms, we determined the values of the elements from a double RLC scheme with two ground connections, forming self-oscillating circuits with variable attenuation, for allowing the extension from a single discharge pulse to multiple ones.