Failure Protection Method for CAN Communication Against EMI Noise Generated by Switched-Mode Power Supplies

Abstract

This article presents a protection method for controller area network (CAN) communication against electromagnetic interference (EMI) caused by switched-mode power supplies (SMPSs). SMPSs generate EMI noise on the communication lines by switching the power semiconductor devices, which often causes communication failure. Conventional EMI reduction methods, such as EMI filters and shielded cables, generally reduce the converter conducted noise and the noise susceptibility of the communication system. However, depending on the system configuration, these EMI reduction methods are not sufficient to prevent communication failure. To resolve this issue, the authors propose an EMI failure protection method that realizes robust CAN operation. The proposed method eliminates the coincidence between induced noise in the communication lines and the CAN sample timing so that no communication failure occurs. Experimental results verify that the proposed method is effective in interference reduction, and the proposed method is revised for resolving the converter output disturbance due to an undesirable shift of switching timing.