On 07/22/2010 09:37 AM, DJ Delorie wrote:
One idea to consider is to start with a solid plane, and cut slots around the sensitive analog parts, like big C shaped moats, squares open on one side. You retain the "big ground plane" conductivity, but you prevent stray currents from using your analog area as a short-cut. Each analog "chunk" can have it's own moat this way, too. If they're near the edge, just cut a thin slot from the edge in.
I've used this approach on some relatively high-speed digital/analog/RF boards. Seems to work pretty well.
Just make sure that if you've got high-speed digital lines that cross into the 'cubicles' they have gnd plane underneath them where they enter - don't let fast signals cross the cuts because then the return currents have to take a different path and that will screw up the signal integrity.
Eric _______________________________________________ geda-user mailing list geda-user@xxxxxxxxxxxxxx http://www.seul.org/cgi-bin/mailman/listinfo/geda-user