On Thu, Jul 22, 2010 at 09:57:11AM -0700, Steven Michalske wrote: > On Jul 22, 2010, at 9:50 AM, Eric Brombaugh <ebrombau...@cox.net> wrote: > > 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.
Now each side of this debate can call you a heretic -- that's a good thing! I'm generally on the single-ground-plane side of this fence, and the one time I ran into trouble, the solution was just as you describe. > > 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. > > > The question is "how fast?". Because you loops may not even matter. But just > remember to keep them small. :-) If you have _any_ signals crossing the slots, you're doing it wrong. - Larry _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user