Effect of GMR recording head resistance on human body and machine model ESD waveforms

The effect of the GMR sensor resistance on HBM and MM ESD current waveforms is studied. It is shown that the sensor resistance can have a significant impact on the peak current and waveform shape, especially for MM ESD testing. SPICE modeling results confirm the experimental data for HBM and MM. It is concluded that if the resistance between devices varies significantly, then reporting failure voltage alone can be misleading, since higher resistance devices will experience less current at the same voltage.