Full Statistical Analysis of an ESD Environment

The authors present a direct and complete method for the statistical characterization of an equipment subjected to electrostatic discharges. The approach relies on the knowledge of the transfer function of the system (or something equivalent) which allows one to evaluate the dependence of the relevant output variables on the parameters which can cause a failure. Since these parameters are, in general, randomly variable, their properties are described through suitable probability density functions whose algebraic manipulation and combination allows one to derive the statistical distribution of the output variables as well. The probability of an undesired response then results from an analysis method which takes into account either the sensitivity on the input variables or their occurrence probability. With the aim of giving a practical example, the method is applied with great detail to the particular case of the coupling of an ESD into a shielded enclosure through an aperture. The way for taking into account a variable susceptibility is also highlighted and introduced in the model.