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Altera_Forum's avatar
Altera_Forum
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17 years ago

LVDS I/O termination

Is an external 100Ohm resistor required at the input of an LVDS receiver I/O pair for the Cyclone III devices? The literature seems to suggest yes and no. Also, if I have "rx_in" as a single-channel LVDS serial input to my deserializer on the FPGA, is it correct to assume that "rx_in", and its complement "rx_in(n)" which the fitter autmoatically assigns, will be converted into a single serial bitstream by the LVDS I/O pair and presented to my deserializer as one rx_in?

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  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    It's not relevant since the differential inputs have dedicated terminations. The TCBs are for dynamic termination.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    --- Quote Start ---

    It's not relevant since the differential inputs have dedicated terminations. The TCBs are for dynamic termination.

    --- Quote End ---

    Got it. Thank you very much for your help.

    :)