Analysis of conducted emissions in CAN bus systems with VHDL-AMS

The increasing number of electronic components in a motor vehicle makes the prediction of EMC behavior more and more crucial. Thus, early in the design phase new methodologies are being implemented in order to estimate conducted emissions. This paper provides application engineers information about the different aspects to electromagnetic emissions of a CAN bus system; how emissions are generated and transformed within the application environment. Behavioral models (VHDL-AMS) are used for system simulations. The description focuses on the interaction between CAN transceivers and the twisted pair transmission line connecting them. Both common- and differential-mode as well as mode conversion aspects are considered. It highlights the fact that electromagnetic emissions from a CAN bus system highly depend on the application environment.