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P82B96: Series 100 Ohm connection for protection.

Kawai
Guru 19775 points
Part Number: P82B96

Hello Team,

Our customer is planning to add 100 ohm in series. This is because in some case user may use unsupported cable which has wrong connection.

Would there be any concern adding 100 ohm such like below ?

Best Regards,

Kawai

  • 0
    TI__Guru 58600 points

    Hello Kawai,

    The 100 ohm resistors will introduce some extra voltage when pulling low. This will be equivalent to the IoL on Tx/RX side and 200 ohms (100 ohms + 100 ohms).

    This should be okay as long as VoL on the Tx/Rx line is below 0.42xVcc.

    My estimate on the set up you've shown is about 2.5mA for IoL so I would expect the VoL to be around 0.5V which is much lower than 5V (0.42*Vcc).

    This looks okay to me.

    Thanks,

    -Bobby

  • 0 in reply to BOBBY
    Guru 19775 points
    Hi Bobby-san,

    Thanks for your support. I had the same understanding.

    Best Regards,
    Kawai