Analysis of the Increase in Radiated Emissions After Applying ESD on the CAN Communication Hamess

The Electrostatic Discharge (ESD) test is frequently conducted as a last sequence of all EMC tests because if products are damaged during the ESD test, then no other tests can be conducted unless customers suggest ESD test to be done as a first step. After the ESD test, Electromagnetic Interference (EMI) performance can be changed, and because of the sequence of Electromagnetic Compatibility (EMC) tests, EMC performance degradation cannot usually be perceived. Among the hard failure modes, we additionally see the phenomenon of Radiated Emissions (RE) levels increasing when ESD applied on the Controller Area Network (CAN) communication lines is studied. When ESD voltage is applied on a CAN transceiver, the silicon die inside CAN transceiver can become damaged and as a result radiated emissions levels can increase, even though the communication performance and the impedance of circuit are not changed. In this paper, the reason for the radiated emissions increase, verification of damaged silicon inside the transceiver, and the solution to this phenomenon are studied.