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Altera_Forum
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16 years ago

Cyclone IV GX LVDS clock input resistor termination

Hi Altera experts, I am designing using the EP4CGX15BF14C8 (I have the transceiver dev board to try my design). Question I want a reference clock for the transceivers so I use a 125Mhz osc...
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Altera_Forum
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16 years ago

Hi Dave,

LVDS doesn't have te be AC coupled. Check the handbook volume 1 page 6-33. This is not about LVDS and not about REFCLK, but I'm sure this scheme also works for LVDS @ REFCLK.

See also volume 2 table 1-2 and the text below. LVDS coupling can be DC. Just keep the common mode voltage below 0.82V. If you can guarantee that, I'm pretty sure it will work.

Good luck, Ton