How to suppress CAN bus interference in intelligent low-voltage monitoring units?

CAN bus interference suppression employs a combination of filtering and protection. A 120Ω terminating resistor is connected in series at both ends of the bus. A CML4532A-101T common-mode inductor (100μH) is used for filtering at the interface. Protection devices utilize ESDLC3V3D3B low-capacitance ESD protection, coupled with an SMBJ24CA TVS diode. Shielded twisted-pair cables are used, with the shield grounded at a single point. PCB design: The CAN interface is kept away from noise sources. With this suppression, the CAN bus can pass IEC 61000-4-2 8kV EFT and IEC 61000-4-4 2kV EFT tests, achieving a communication rate of 1Mbps.