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SN65HVD235: Mix 3.3V CAN and 5V CAN in same CAN bus

Part Number: SN65HVD235
Other Parts Discussed in Thread: SN65HVD1050

Hi team,

 

Customer will use both 3.3V CAN (SN65HVD235) and 5V CAN (SN65HVD1050) in the same CAN bus.

 

-        Could both 3.3V CAN and 5.0V CAN use in the same CAN bus ?

-        If yes, are there any reference design, application report or material that describes it is no problem as CAN standards ?

-        Should customer the ratio between 5V CAN and 3.3V CAN in the same CAN node ?
         If yes, what should customer think about ?
         e.g.
        Are there any issue if there are five nodes at 5V CAN and 2 nodes at 3.3V CAN ?

 

Thank you and best regards,

Michiaki

  • Hello Michiaki-san,

    It is OK to interoperate between any ratio of 3.3-V-powered and 5-V-powered CAN transceivers on a shared network.  Both types of transceivers would generally specify similar output voltage amplitude (i.e., >1.5 V differential into a 60-Ohm load during dominant states) and input thresholds (i.e., differential inputs <500 mV are considered recessive while differential inputs >900 mV are considered dominant).

    The following application report goes into detail on how the two types of transceivers are interoperable and how to mitigate the impact of the different supply voltages on common mode noise using split termination:

    https://www.ti.com/lit/an/slla337/slla337.pdf

    If you have any further questions after reviewing the above report please let me know.

    Regards,
    Max