Ikuko Mori

Transfer impedance of new-type calibration target and reconstruction of injected currents for air discharges from electrostatic discharge generators

We measured in the frequency range from 300kHz to 6GHz of the transfer impedance of a commercially available calibration target newly developed for immunity testing against electrostatic discharges (ESDs) being prescribed by the International Electrotechnical Commission. The result showed that the transfer impedance has an almost flat frequency response up to 6GHz, while resonance phenomena were still observed at frequencies around 2.5 and 5GHz. With this result, the waveforms of injected currents onto the target were reconstructed from the observed output voltages for air discharges of an ESD generator with a charge voltage of 2kV.

Severity evaluation of immunity test for air and contact discharges of ESD generators

An immunity test method for electrostatic discharges (ESDs) is being specified in the IEC 61000–4–2, in which two types of discharges, contact and air discharges of ESD generators (ESD-guns), are given. To achieve an immunity test of higher quality, severity evaluation of discharge currents for both the current injection methods is essential.

Rise Time Limit of Discharge Current for Air Discharge of an ESD-gun

Using a 12-GHz digital oscilloscope, we measured discharge currents for air discharge of an ESD-gun with charge voltages below 1 kV, and demonstrated that the rise time reached the limit of measurement. Based on the Gaussian response of the oscilloscope, the rise time limit was investigated