ESDガンの接触放電に対する放電電流波形の周波数スペクトルと不確実性(電力,生体,一般)

概要

論文の詳細を見る
International Electrotechnical Commission (IEC) has prescribed an immunity test (IEC61000-4-2) of electronic equipment against electrostatic discharges (ESDs), in which a discharge current to be injected onto equipment under test is being specified by a Heidler formula. As for the waveform, however, not the whole-waveform but only the rise time, the first peak, and the current amplitudes at 30 ns and 60 ns are being specified in the time domain together with their uncertainty so that a commercially available ESD generator (ESD-gun) shall be checked by injecting a current onto an IEC recommended calibration target before testing. In this study, to clarify the discrepancy between measured discharge currents and the above-mentioned calculated current in the frequency domain, we measured discharge currents for contact discharges of an ESD gun onto the calibration target with respect to various arrangements of the ESD gun and its earth return cable, and obtained the ratio of their current frequency spectra to the calculated current spectrum from the Heidler formula. As a result, we found that according to the inclination of the ESD gun and arrangement of the earth return cable current spectra vary by -10dB in the frequency range from 10 MHz o 200 MHz and by 15dB at frequencies over 300 MHz. This finding suggests that the arrangements of an ESD gun and its earth return cable should affect immunity testing results.
2009-12-11