[Open-graphics] Problem with OGD1: Can anyone advise on good low-jitter

[Dieter]

> We've discovered that the clock generators in the Xilinx FPGA part are
> lousy for generating video clocks.  We're seeing like 900ps of jitter,
> which causes artifacts on DVI monitors at resolutions as low as
> 1280x1024 when the cable gets beyond a certain length.  (I don't
> recall all the details.)
> 
> One option is to use the clock generators in the Lattice part, but
> even they have like 400ps of jitter, and they also severely limit the
> range of frequencies we can generate.
> 
> So the best solution we can come up with is to put on some external
> clock generators.  One for each video head.  Problems:  (1) more time
> to mod the design, (2) up to $15 each for the generators, (3) we have
> no idea what generators to use, how good they are, how to wire them.

What cable length are we talking about?  Would a cable equalizer be useful?
The NS part below (not a recommendation, just something google found) claims
over 40 meters using 24 AWG DVI/HDMI cable at 1.65 Gbps, over 30 meters at
2.25 Gbps (1080p).  $6.95 each in 100-unit quantities

http://www.national.com/news/item/0,1735,1241,00.html