Ferrite-Based Approach for Optimising Electrostatic Discharge Generator Waveforms

Abstract

Electrostatic discharges (ESD) remain a significant challenge in electromagnetic compatibility testing due to their high-frequency spectral content and the increasing complexity of modern electronic systems, which incorporate higher integration densities and faster signal transitions. The upcoming revision of the system level ESD immunity testing Standard IEC 61000-4-2 introduces a new parameter regulating the second peak of the ESD current waveform produced by the ESD test generators. This revision is expected to render many existing ESD generators non-compliant, posing a costly issue for testing laboratories as it necessitates expensive modifications or complete generator replacements. To address this challenge, a cost-effective alternative is proposed, utilising ferrite clamps around the grounding cable of the ESD generator to modify the second peak parameters. A workflow-based methodology is introduced, including the identification of non-compliance, evaluation and ranking of ferrite configurations and an investigation of saturation effects to ensure sustained performance. Beyond ensuring compliance, this methodology can also be applied to optimise the second peak waveform parameters, improving the overall match to the ideal waveform of IEC 61000-4-2. By providing an effective and adaptable solution, this approach enhances test accuracy, improves reproducibility and reduces costs associated with equipment replacement and upgrades.