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DS100BR210/DS100KR800 cable length at 3Gbps

Other Parts Discussed in Thread: DS100KR800, DS100BR210

Hi all,

According to presentation material, 
DS100BR210 and DS100KR800 can extend reach of 10-Gbps signals over 50+ inches of FR-4 or 20m of 26-AWG copper cable.
When the data rate is 3Gbps, can DS100BR210 or DS100KR800 extend a length to over 30m of 26-AWG copper cable?


Regards,
Toshi

  • Hello Toshi-san,

    The total length extension will depend on a few things including where the device is placed, the total loss of the line, and the highest EQ that our device can provide at the given data rate. As shown in the DS100KR800 datasheet, the EQ boost that our device can provide is lower at lower data rates (16.1 dB at 1 GHz vs 33.8 dB at 5 GHz for EQ = 0xFF), but the line loss will also be lower at lower data rates, so the device may still be able to extend to the desired length.

    In order to better evaluate if this would be possible, I would like to ask a few questions.

    1. When considering 30m of 26-AWG copper cable, what do you expect the total line loss to be at 3 Gbps? Our information suggests that at 3 Gbps, the highest EQ setting would provide approximately 20-21 dB of equalization boost.
    2. How would the device be set up along the line? Would the device be in the middle? 20m down the line? At the end? What would the total loss be before and after the device?

    Best Regards,

    Michael

    Analog Factory Applications

    High Speed Datapath Solutions

  • Michael-san,
    Thanks for your response.

    My customer plans to use these devices for 3Gbps SDI signal transmission,
    and plans to use these devices at the end of wire or at both side.

    FPGA ------------(30 meter  cable)---------------> DS100KR800 -> FPGA

     or

    FPGA <-> DS100KR800 <-----------------(30 meter cable) ---------------> DS100KR800 <-> FPGA 

    At this time, they could not answer the total line loss and probably, it may be considered by including BER.

    Anyway, could you please tell me the specification of 26-AWG which you tested?
    Is the tested cable a coaxial type or a twist pair type ? 

    Regards,
    Toshi 

     

     

  • Hello Toshi-san,

    The test data that we have for the cable is taken from the datasheet. The cable referred to in the datasheet is a 30 AWG cable that is likely a Twinaxial cable.

    To clarify, the maximum equalization boost that the DS100KR800 can provide at 3 Gbps is 20-21 dB because the EQ boost is lower at lower data rates.

    Best Regards,

    Michael

    Analog Factory Applications

    High Speed Datapath Solutions