This point brings to (my) mind related questions:
If a signal crosses supply domain, is there any possiblity
of return currents trying to flow on power planes?
I would think that 5v > 3.3v and the complement would have
an overwhelming proportion of return current forced to the
ground layer alone, as long as these signals are routed such
that a reference ground layer is available.
Can the power-vs-ground as return mechanism be predicted,
if so, is there any simplistic rule of thumb (for physical
design folks with many thumbs, such as myself)?
Many thanks in advance,
-- Jeff Seeger Applied CAD Knowledge Inc Chief Technical Officer Tyngsboro, MA 01879 jseeger "at" appliedcad "dot" com 508 649 9800