This article describes the benefits and limitations of using galvanic isolation in CAN interface boards, highlighting improved noise immunity, reduced ground loop issues, and a slight reduction in bus length.
APPLICABLE PRODUCTS
CAN-IB100/PCIe, CAN-IB200/PCIe, CAN-IB300/PCI, CAN-IB400/PCI, CAN-IB520/PCIe mini, CAN-IB600/PCIe, USB-to-CAN V2, USB-to-CAN FD, CAN@net NT
QUESTION
Is a CAN interface board with or without galvanic isolation more suitable for my CAN network?
ANSWER
A CAN interface board with galvanic isolation is more noise immune and prevents a ground loop. The potential difference occurring because of the different power supplies for different CAN nodes does not influence the transmission quality.
The galvanic isolation reduces the maximal possible CAN bus length by approximately 10 meters. (The typical CAN signal delay of the galvanic isolation is approximately 50 ns).
Please note, that the CAN_GND wire should be connected even if a galvanic isolation is used.