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LX21EVK01 Channel Link III EVM

Other Parts Discussed in Thread: LX21EVK01, DS92LX2121, DS92LX2122, DS92LX1622, DS92LX1621

Hi,

I am studying and looking for a cable for SerDes(LVDS).

I have found the following document about LX21EVK01 (Channel link III EVM).

www.tij.co.jp/.../lx21evk01

There describes that mini-USB cable(2m length) is used to connect DS92LX2121 with DS92LX2122.

My question is, is it possible to propose my customers to use USB cable for SerDes?

If yes, how long can we communicate between TX/RX with USB cable? 10m is OK?

And how about another cable, for example "Cat 5" cable, is it also possible to use for SerDes?

Thanks in advance.

  • Hi Suzuki-san,

    It is hard to put a definite limit on the cable reach, as other factors play into the maximum reach, such as insertion loss per unit length (related to wire gauge and material) and crosstalk (related to shielding). We have not tried communication with 10m of USB cable, but we do know that the amount of cable reach decreases as the PCLK frequency increases.

    The only data that I have been able to find for Channel Link III cable reach so far is a test that we ran in the past with the DS92LX1621/DS92LX1622 SerDes, using a Hitachi Manchester CAT6  4-Pair/24-AWG cable. After adjusting the EQ to find Fmax with PRBS-7 data passing through, the max cable length supported for 50 MHz was around 25 m.

    I recommend that you look at the EQ capability of the DS92LX2122 and determine whether the cable insertion loss at Nyquist frequency can be resolved by the EQ in order to get an idea of whether the DS92LX2121/22 can support the interconnecting media.

    Thanks,

    Michael

  • Hi Michael-san,

    Thank you very much for your reply!

    I understood well and your suggestion would be very helpful for me, thanks.

    Best Regards,