Failure Protection for Controller Area Network Against EMI Emitted by Buck Converter

This study focuses on data transmission failure of a controller area network (CAN) caused by common-mode (CM) noise emitted from a buck converter. CM noise emitted from a switching converter is a major cause of transmission failure in CANs and seriously undermine the communication performance. To prevent this problem, the CAN failure mechanism is analyzed by using a novel test bench, where a buck converter and a CAN are closely installed. Then, a simulation model is developed to analyze how the CM noise from the buck converter is converted into differential-mode noise in the CAN communication lines. It is found that a CAN bit error occurs when the CM noise is induced to the CAN communication lines at a CAN sample timing. To suppress the CAN transmission error, the authors propose a converter control method to not coincide the CM noise with the CAN sample timing, and apply an additional approach to suppress converter output disturbance. The effectiveness of the proposed method is verified experimentally.