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SN65LVCP114: SN65LVCP114 for 10GE/GE

user3660867
Prodigy 230 points
Part Number: SN65LVCP114
Other Parts Discussed in Thread: DS100MB203

Tool/software:

Hi 

We would like to use the SN65LVCP114 on a line card in a chassis switch, with an 10G/GE Ethernet optical port(SFP+) on the line side and Host interface connected to the Active and Standby switch chips respectively. There are a few questions I would like to confirm:

  • Does the SN65LVCP114 terminate the timing information for serdes. Can both switch chips recover the clock from the signal at the same time for SyncE function?
  • What is the maximum Propagation Variation for the SN65LVCP114 in a 10GE and 1GE interface application?
  • If the line side needs to support eight 10GE/GE optical ports, is there a more suitable alternative chip that can be used?

Thanks

Fang Youxiang

  • 0
    TI__Mastermind 28960 points

    Hi Fang,

    1. I believe there is a misunderstanding, SN65LVCP114 is a redriver which does not include clock and data recovery function like retimers do. This device simply applies receive equalization, muxes/demuxes the channels, and drives the output signal without any clock extraction.

    2. There is no variation in propagation delay based on data rate. There is some pair-to-pair skew and part-to-part skew in propagation delay.

    3. I can share part recommendations if you share a bit more information about your use case.

    • How will the mux/switch feature be used?
    • Do you require clock and data recovery (retimer)?
    • Can you share a system block diagram?

    Best,

    Lucas

  • +1 in reply to Lucas Wolter
    Prodigy 230 points

    Hi Lucus,

    Thank you for your prompt reply:
    We understand that the SN65LVCP114 is a rediver and Mux/Demux chip and will not have clock recovery. Therefore we need to extract the line recovery clock on the Switch chip for SyncE.

    The block diagram below shows our idea using the SN65LVCP114.
    One of our concerns is that since the Switch chip needs to recover the clock from the line, we need to make sure that the LVS does not affect the functionality and performance of the Switch's recovery clock.
    Also, we are concerned about the maximum variation of the signal delay in the SN65LVCP114. because it may affect the performance of the PTP 1588.

    regards,

    Fang Youxiang

  • +1 in reply to user3660867
    TI__Mastermind 28960 points

    Hi Fang,

    Thank you for your clarification. I don't expect the redriver to negatively impact clock recovery because it simply applies gain and equalization without influencing the clock component of the signal.

    Although I'm not especially familiar with PTP 1588, I expect a PTP compatible switch to be capable of skew compensation. I suggest checking your switch datasheet for an input skew specification.

    If you are concerned about the 100ps max part-to-part skew of SN65LVCP114, I recommend considering DS100MB203, which has part-to-part skew of 40ps. The tradeoff is that DS100MB203 only supports 2 lanes, so 4 pcs are necessary to support 8 SFP+ ports.

    Best,

    Lucas