What is the correct (preferred) method of removing the residual charges on the test point on the EUT?
NoiseKenA cable with 470 kΩ bleeder resistors, similar to the one used with the horizontal coupling plane and vertical coupling plane is the preferred device to remove charges. The cable with bleeder resistors may remain installed during the ESD test when functionally allowed. The presence of the cable with the bleeder resistors can influence the test results of some equipment.
A test with the cable disconnected during the ESD pulse takes precedence over the test with the cable installed during the test, provided that the charge has sufficiently decayed between the successive discharges. As an alternative, the following options may be used:
- the time interval between successive discharges shall be extended to the time necessary to allow natural decay of the charge from the EUT;
- sweeping of the EUT with a grounded carbon fiber brush with bleeder resistors (for example, 2 × 470 kΩ) in the grounding cable.