EMC #49. IEC / EN 61000-4-2 ESD Testing Explained: Electrostatic Discharge Immunity & Test Setup. скачать в хорошем качестве

EMC #49. IEC / EN 61000-4-2 ESD Testing Explained: Electrostatic Discharge Immunity & Test Setup.

EMC playlist. Watch these video to understand more on EMC.    • EMC #1. Electromagnetic Compatibility EMC=...   For access to this presentation materials, membership is required: I need the Material PPT Sent me an email to [email protected] If you need the whole playlist material, send me email and we discuss. Give me some time to response. Thanks. What is IEC / EN61000-4-2 IEC 61000-4-2 is commonly called ElectroStatic Discharge (ESD) immunity compliance standard for commercial electronics to attain CE product certification. It is an international test standard that outlines electromagnetic immunity requirements for electronic equipment when exposed to ESD generated from a human body or metal objects. Why we need to do IEC / EN61000-4-2 test? Standard assumes that the source is an electrified human body discharge and testing simulates the current waveform generated in those conditions. The occurrence of ESD is impossible to predict, so the best method is to take as much preventative measures to prevent damage or malfunction when it does occur. Since IEC 61000-4-2 is a test standard and not a product standard, you have to check ESD test levels from applicable product standard. For instance, for medical devices, IEC/EN 60601-1-2 standard defines test levels as ±2kV, ±4kV and ±8kV for air discharges and ±2kV, ±4kV and ±6kV for contact discharges. IEC/EN 60601-1-2 defines ESD test levels and IEC 61000-4-2 refers how to perform ESD testing. Guidelines Points of application - all points that are accessible to the user in normal operation; not necessarily pins of open connectors nor points accessible only during maintenance or servicing. EUT / DUT is subjected to 3 types of discharge. 1) Direct contact discharge to the EUT / DUT is always preferred or 2) indirectly through vertical / horizontal coupling plane. 3) Air discharge is used where direct contact cannot be applied. Number of discharges - normally ten in each polarity ( Pos & Neg) to each point of application. Mode of application - test generator must be perpendicular to the surface of the EUT / DUT; for air discharge, the tip must approach the EUT as fast as possible without causing mechanical damage; for contact, the tip must touch the EUT before the discharge. It is important to make sure that the room where the test is conducted is at a temperature of 15°C to 35°C and relative humidity is between 30% and 60%. The direct discharge test simulates the human body model of electrostatic discharge and must be set up to recreate similar conditions. It is important to make sure that you have the proper grounding system in place before you begin testing. When using a tabletop for testing, it have a horizontal coupling plane on top of the table but below an insulation sheet. This should be connected to a ground reference plane on the floor using a 2 x 470k"Ω" bleed resistor cable. If the EUT is too large for a tabletop, place the EUT on an insulation pallet that is at least 0.1m in height. For direct discharge test, place the ESD gun to the point of test on the EUT and discharge at 1 sec intervals. This should be performed at least 10 times at both positive and negative polarities and the results recorded. For indirect discharge test, the same process is repeated except that the discharge goes to the vertical or horizontal coupling plane rather than directly to the EUT. A vertical coupling plane should be set up 10 cm from the EUT and connected to the ground reference plane using the bleed resistors. The air discharge method is used for cases where contact discharge testing cannot be applied like for example, EUT / DUT has a moving part or some separation. In this case, the ESD test gun is moved towards the EUT (without touching) until the distance is small enough causing a discharge through the air gap to the EUT/DUT. The air discharge method is commonly used for replicating real word events as well as when contact discharge is not possible. This simulates real situation as most discharges occur without having the intention of touching the EUT / DUT. Multiple discharge points may be required for testing, depending on type of EUT / DUT