Equivalent circuit modeling of discharge current injected in contact with an ESD-gun

The transient electromagnetic (EM) fields caused by an electrostatic discharge (ESD) have broadband frequency spectra, which cause serious failure to high-tech information equipment. From this perspective, ESD testing for the EM immunity of the equipment is specified by IEC 61000-4-2, in which the detailed waveform of the discharge current injected onto the IEC recommended Pellegrini target in contact with an ESD-gun is prescribed for calibration. However, the factors for determining the current waveform remain unclear, and thus the IEC prescribed current waveform is unlikely to be injected into actual equipment, In this study, based on the structure of an ESD-gun, an equivalent circuit modeling is proposed for analyzing the discharge current injected onto a 50-Ω SMA connector instead of the IEC target that has frequency-dependent transmission characteristics. Its validity is confirmed by comparing the calculated current waveform with the measured result. The proposed circuit modeling is also validated from measurement of the discharge current injected onto a transmission line by the ESD-gun. © 2004 Wiley Periodicals, Inc.