Time-domain measurements using near field scanning method for fast transient current reconstruction

Direct Electrostatic Discharge (ESD to connectors pins is used to evaluate the system level susceptibility. Nevertheless, it is difficult to determine accurately the sensitive areas. Indeed, the propagation of an ESD through a PCB is still very difficult to predict even for a simple system. The lack of models at both IC and PCB levels and the limited computational resources force to simulate the system with great simplifications. Consequently, we can only estimate roughly the current spreading generated by the transient pulse throughout the application. The near field scanning (NFS) method using magnetic or electric probes is a promising method to capture the current spreading as a function of time and location through the system. This article describes the measurement method, a data process for current reconstruction and the application on two cases: a microstrip line and a DC/DC converter PCB. Based on the analysis of these examples, the paper helps to better understand the transient pulse propagation throughout a PCB.