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DS90UB934-Q1: DS90UB934-Q1 Display flicker when doing EMC RI Test

Part Number: DS90UB934-Q1

Dear TI:

When custom do  EMC RI Test ,found the display flicker.  The phenomena are described  as fellow:
1. When the static electricity hits the shielding layer of the coaxial connector harness, the display it will flicker.
2. when the field strength increases to 1.2G, 1.8G, and 1.945G.the display it will flicker.  However, Wrap the POC circuit with copper foil, and connect the coaxial connector mcx and the shield with copper foil, it will not flash.
3. Change with the shaft machine, MMC,SMA,the phenomenon is as above.
4. Whether ds90ub934Q1 has a register, such as EQ or AEQ, can improve the new immunity, or signal quality, such as eye diagrams. And register setting method.

POC Circuit:
power.pdf



 

  • Thanks for the question.

    Please try the following.

    • Set PAR_ERR_THOLD_HI to FF and set PAR_ERR_THOLD_LO to FF.  If that does not work, disable RX_PARITY_CHECKER_EN.
    • Try a CMC on the RIN path
    • Try ESD or fast TVS diode at the cable connector
    • Make sure the cable is new with 10 or fewer insertions. 
    • If you are not using a 462 cable, try that.
    • Consider STP cable.
    • Monitor the voltage rails during the ESD zap.  If they move outside the allowed VDD range, add filter caps.

    Can you attach a setup photo?  Let me know how these work for you.

    Mike

  • Hello,

    Any feedback here? Did you have a chance to address Mike's comments above?

    Thanks,

    Casey