System-Level Modeling Methodology of ESD Cable Discharge to Ethernet Transceiver Through Magnetics

Abstract

When a charged cable is plugged into an Ethernet connector, a cable discharge event (CDE) will occur. Ethernet transceiver pins are often affected by CDE as they are usually unshielded. The discharge current couples via the transformer and common mode chokes to the physical layer-integrated circuit and may damage it. This paper describes a methodology for CDE system-level modeling in SPICE taking the cable geometry into account via full-wave modeling and cross-sectional analysis. A charged cable model, a nonlinear magnetics model, an Ethernet transceiver pin model, and the traces in the system are combined to create a complete model. An Ethernet system suffering cable discharge was selected to illustrate the methodology. The simulation is compared to measurements.