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Original question:

DS90UB948-Q1: The factors to result in lock loss

DS90UB948-Q1: LOCK lost EMC test

Tobias
Prodigy 40 points

Part Number: DS90UB948-Q1

Hello,

we have the same problems as descibed in the related question.

Is there any further information on the issue in the meantime?

The lock loss problem occurs between 600MHz and 1000MHz.

Thanks & Best Regards,

Tobi

  • 0
    TI__Mastermind 38760 points

    Hi Tobias,

    As far as I remember, we do not have any issue getting 948 to pass EMC. Can you tell me which test you failed due to the lost of lock RI, RE, BCI? Can you share the EMC testing results?

    Aaron

  • 0 in reply to Aaron Heng
    Prodigy 40 points

    Hi Aaron,

    this was the test:  Radiated Susceptibility - disturbing field 100V/m CW

    We started at 200MHz and from 600MHz onwards there were the described losses of lock.

    Tobi

  • 0 in reply to Tobias
    TI__Mastermind 38760 points

    Hi Tobias,

    The 948 doesn't have external input reference clock. It uses the PCLK to generate the desired the frequency. If it's in dual link then the frequency is too low. If it is dual link, it has to be a minimum of 50MHz. When I used the frequency you provided and divided it the encoding of 600MHz/35=17MHz; 1000MHz/35=28.5MHz. It doesn't meet the minimum input clock requirement.

    Aaron