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 offers improved noise immunity and prevents ground loops. The potential differences caused by separate power supplies for different CAN nodes do not affect transmission quality.
However, galvanic isolation reduces the maximum possible CAN bus length by approximately 10 meters (typical signal delay introduced by the isolation is about 50 ns).
Please note that the CAN_GND wire should still be connected, even when galvanic isolation is used.