Circuital and numerical modeling od ESD coupling to shielded cables

The discharge current in the contact mode and the voltage induced inside a shielded cable that interconnects two shielded enclosures are simulated following two approaches: the first is circuit-oriented and is derived by the transmission line theory, while the second is based on the numerical solution by using the Finite Integration Technique. The ESD generator is numerically modeled with conductive material, dielectric material and lumped circuital elements inside in order to reproduce the reference current discharge investigated by the working group in charge to prepare a new IEC 61000-4-2 standard. The numerical or circuital simulated current on the shield of the cable is then used to calculate the disturb on the loads of the cable by using a transmission line model that implements the transfer impedance concept. The proposed models are validated by comparison with measurements. Finally, different design choices are investigated.