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LMK1D1216: Effect of Unterminated LVDS Outputs

Part Number: LMK1D1216

Hello,

I have an application where they can be any number (0 - 16) of devices downstream loading/terminating the clocks generated by this LMK1Dxxxx and I'm trying to understand the performance impact that I would see when a number of those LVDS output pairs remain unterminated. 

Take the worst case scenario where 1x clock pair is being terminated by a downstream device and the other 15x are unterminated. How might that affect the quality of the one utlized (i.e. terminated) LVDS pair?

Thank You,

David

  • Hello David,

    The standard Vos for the outputs are shown as below:

    If an unused outputs is not terminated, the adjacent outputs Vos will be degrade by a couple mVpp (0-5 mVpp). The effect will not be significant, but there will be a slight degradation.

    Regards,

    Kia Rahbar

  • Thanks Kia. I just wanted to make sure the effect wasn't compounded by the number of unterminated loads, but from what you're saying it sounds like the degradation is localized and pretty minimal.

    Thanks Again,

    David