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Original question:

SN65HVD82: SN65HVD82 working voltage

SN65HVD82: working under 3.3V

Mia Ma
Intellectual 2515 points
Part Number: SN65HVD82
Other Parts Discussed in Thread: THVD1400, SN65HVD72

Hi team,

I have a wrong power rail design of the part SN65HVD82, and the Vsupply is 3.3V and out of the EC table supply voltage range and it could normally work.

And there is a 3.3 description in above table in our datasheet.

could you please help to clarify what is the side effect if the part is kept working under 3.3 supply voltage?

Thanks

Best regards

Mia Ma

  • 0
    Guru 317260 points

    Below the minimum supply voltage of 4.5 V, correct operation is not guaranteed.

    The description in table 3 is wrong; it was probably copied from the SN65HVD72 datasheet. Also consider the newer THVD1400/10.

  • 0
    TI__Guru 52352 points

    Hi Mia,

    Clemens is correct - under 4.5V operation is not guaranteed - the device may operate, but if it does it will not meet datasheet specifications listed and will probably land outside of RS-485 standard. The table is wrong - it was just copied from a different datasheet - thanks for bringing this to our attention as this will need to be fixed.

    The THVD1400 is a good option as it has the same pinout and can operate at 3.3V. The transient protection circuit shown can be applied to multiple RS-485 devices as its the architecture that matters there so the same application niche can be filled with the 1400 - the largest difference is that it is a bit faster (500Kbps max compared to 250Kbps max) but you can run it lower than max speed if necessary and both devices will have little higher harmonic content due to max data rate (which is defined by transition time) being relatively slow for both devices.

    Please let me know if you have any other questions!

    Best,

    Parker Dodson