• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 32 subscribers
  • Views 457 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB901 DS90UB902 Failures

John Proctor
Prodigy 30 points

I have seen multiple DS90UB901 and DS90UB902 units fail on my boards.  I am interconnecting them across a 7m cable and the outputs seem to stop working after some time.  I believe one or both of the signaling pair is being destroyed (EMI?).  Replacing the IC's fixes the problem.

I am AC coupling on both ends of the cable at the IC pins.  I do not have external termination resistors for the LVDS signal as the datasheet says they are internally terminated.

Is there a need for external clamping diodes or resistors?

Has anything similar been seen?

  • 0
    TI__Expert 5210 points

    Hi John,

    You do not need external termination resistors as these are integrated per the datasheet; you also should not need external clamping diodes.

    What cable and connectors are you using for your setup? Placing the devices in BIST (built-in self test) mode can also help pinpoint any errors you are seeing.

    Just to be clear, when you replace the 901/902 IC's with identical devices, do you see any more output errors? If you could give a brief description of your current SerDes setup, this would be very helpful.

    Best,

    Sean