I have four electronic modules with on-board CAN circuitry, so each module serves as a node. Each module is at a different reference potential. How can I connect all these nodes to a common CAN bus?

  • 2
    \$\begingroup\$ Schematic or it didn't happen. \$\endgroup\$
    – winny
    May 29, 2018 at 6:54
  • \$\begingroup\$ What is the span of those different reference potentials? 7.3 volt? \$\endgroup\$ May 29, 2018 at 23:16

1 Answer 1


Use an optical isolator. You can buy them readily made. Please check if the isolation voltage is big enough for your application.

  • \$\begingroup\$ Hi Sascha, Thanks for the answer. The difference in the reference potential of nodes is around 28V. Can you explain your answer in terms of power source of optical isolator and integrity of CAN signals at the output of isolator. \$\endgroup\$
    – Anand
    May 29, 2018 at 5:10
  • \$\begingroup\$ @Anand: I am afraid that my answer contains as many details as your question. Isolating 28V should not be a problem, but in respect to oprtating optical isolators on this bus and the implications on your application, i recommend that you look up some specific datasheets and see how these fit into your plans. \$\endgroup\$
    – Sascha
    May 29, 2018 at 14:38
  • \$\begingroup\$ Yes, isolation. With Si8621 or ISO1050 for example. \$\endgroup\$
    – Jeroen3
    May 30, 2018 at 5:46
  • \$\begingroup\$ @Sascha: Since CAN is a two way communication, I think using optical isolator will not serve the purpose. \$\endgroup\$
    – Anand
    May 30, 2018 at 11:58
  • \$\begingroup\$ @anand: did you Google for "optical isolation can bus"? I guess the commercially available isolators actually contain several channels in both direction. \$\endgroup\$
    – Sascha
    May 30, 2018 at 13:49

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