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TCAN332: TCAN332DCNR

Yuvakumar Manavalan
Prodigy 10 points
Part Number: TCAN332
Other Parts Discussed in Thread: TCAN1043A-Q1, TCAN1162-Q1

Tool/software:

Hello team,

We are using TCAN332 CAN transceivers for our application.

Our application requires 180 nodes without any repeater, theoretically this CAN transceivers can support 110 nodes.

Can you suggest any alternate transceivers that can support 180 nodes without repeaters?

What's the maximum distance and the other requirement to satisfy this 180 nodes support, in our case our maximum length is 3 meters (no cables involved). all are PCB mounted.

  • 0
    TI__Guru 54666 points

    Hi Yuvakumar,

    A device with with a high common-mode input impedance supports more nodes.

    Unfortunately other devices I found with higher RIN are not p2p. See TCAN1162-Q1, TCAN1043A-Q1.

    To satisfy 180 nodes, tradeoffs from slightly reduced noise immunity should be considered I.e., can increase termination resistance up to 80 -100 ohms. Optimizing PCB layout for low capacitance traces and connectors (<10 pF per node) can also help I.e., further minimize stub lengths, keep traces short, and use daisy chain layout rather than stubs.

    Alternatively, consider the higher RIN transceivers supporting 200+ nodes based RIN, thanks.

    Best Regards,

    Michael.

  • 0 in reply to Michael Ikwuyum
    Prodigy 10 points

    1) If i choose TCAN1162-Q1 as one node do i need to change rest of the nodes to the same part number to support 180 nodes or we can use any transceivers that does not support 180 nodes (TCAN332)?

    2) What would be my speed if i connect 180 nodes (calculation) in our case for the maximum length as i mentioned as 2 meters.

    Kindly help me out with the calculation for Termination, speed and nodes loaded into this transceiver or share me any supporting document that explains the calculation

  • 0 in reply to Yuvakumar Manavalan
    TI__Guru 54666 points

    Hi Yuvakumar,

    1) Any can be used. However, be mindful of how much can be supported by each. I.e., safer to use a recommendation that can fully support all nodes.

    2) Speed depends on many factors such as network topology, stub lengths, total loading etc.

    • 2 meter bus typically would have 20 ns of delay (2 * 2 m * 5 ns/m from the prop speed in a twisted pair cables) with max theoretical CAN speed t_bit > 5 * 20 ns. This gives about 100 ns which equates to 10 Mbps theoretically (1/100ns).
    • Similarly, the data sheet estimates average tpd from tpdL and tpdH as 125 ns I.e., up to 8 Mbps.
      • However, bus loading increases capacitance and limits speed. Hence, up to 500 kbps is more realistic / practical with 180 nodes.
      • You can see how mixing with TCAN332 will increase loading, further limiting speed as low as 250 kbs.

    Please see this app note (https://www.ti.com/lit/an/slla486b/slla486b.pdf?ts=1742238556345&ref_url=https%253A%252F%252Fwww.google.com%252F and https://www.onsemi.com/pub/collateral/and8376-d.pdf) for more information, thanks.

    Best Regards,

    Michael.