Re: [SI-LIST] : Cross-talk Concerns

Daniel Lake (danla@emicx.mentorg.com)
Thu, 16 Jul 1998 16:56:46 -0700

Alex,
There will always be SOME effect on each trace from all other parallel
traces no matter what the separation distance or materials. The
question you need to ask is, "How MUCH crosstalk can you tolerate?" If
you have a ground plane and two dielectric planes in between your victim
on layer 3 and the agressor on layer 1, the effect of the agressor will
most likely be orders of magnitude less than any other parallel
agressors on the same plane (layer 3).

-- 
Dan Lake
danla@icx.com

Software Support Engineer Interconnectix

Mentor Graphics Corporation 8005 SW Boeckman Road Wilsonville, OR 97070-7777 Support: 800-547-4303 Fax: 503-685-4897

Alex Theodorou wrote: > > I'm thinking about designing a 6 layer circuit board > with the following stack-up: > > air > ------layer 1: digital signal traces(50 ohm microstrip)/power > distribution > FR-4 > ------layer 2: digital ground plane > FR-4 > ------layer 3: digital signal traces(50 ohm stripline)/power > distribution > > FR-4 > > ------layer 4: analog signal traces/power distribution > FR-4 > ------layer 5: analog ground plane > FR-4 > ------layer 6: analog signal traces/power distribution > air > > If there is a trace on layer 1 which mirrors a trace > on layer 3, do I need to be concerned with crosstalk induced > by a signal on the layer 1 trace onto the layer 3 trace, even > though there's a conducting plane (layer 2) between the two > traces? > > Thanks in advance for any explanations. > > -Alex Theodorou