How does the EPSCAN bus suppress common-mode interference?

Suppressing common-mode interference on the CAN bus in an EPS (Electronic Power Controller) is crucial for ensuring reliable communication. Measures include:

1. Using common-mode chokes: Connecting common-mode inductors in series on the CAN_H and CAN_L lines, such as the CML3225A-101T or a common-mode filter specifically designed for the CAN bus, whose impedance curve should cover the frequency range corresponding to the CAN communication rate (e.g., 500kbps).

2. Bus termination matching: Installing a 120Ω terminating resistor at each of the two end nodes of the CAN network to suppress signal reflection, which also helps stabilize the common-mode voltage.

3. Shielding and grounding: Using shielded twisted-pair cable for the CAN bus and reliably grounding the shielding layer at the device end (ideally at both ends) to provide a discharge path for externally coupled common-mode interference.

4. Isolation design (optional): For long distances or situations where the ground potential difference may be large, using isolated CAN transceiver modules.

5. Optimized wiring: Keeping CAN lines away from power lines and high-current wires to reduce coupling. Common-mode interference is comprehensively suppressed through filtering, shielding, and good grounding.