Jack -

The simple answer is, YES.

The slightly more complex answer is that lines can act as both aggressor and
victim.  Long parallel runs are extremely susceptible, so buses are very
prone to crosstalk.

If possible keep a separation of 3-5 time the trace width for long (greater
than an inch) parallel runs. If not try to break things up some so that no
single section of parallel run exceeds the 1 inch mark.

Good Luck,

Jeffrey McGlaughlin
Sr. PCB Designer
Battelle Memorial Inst.
Columbus Ohio
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                -----Original Message-----
                From:   Olson, Jack [mailto:[log in to unmask]]
                Sent:   Friday, April 28, 2000 5:53 PM
                To:     [log in to unmask]
                Subject:        [DC] parallel trace runs

                Boy, this has been a rough week....
                I have been trying to learn a little more about signal
integrity, and I'm
                confused again.

                Most articles discuss crosstalk in terms of a "hostile"
trace and a "victim"
                trace, but what I need to look at is 32 parallel traces
running about 10
                inches. We want to run them as close together as possible,
but for such a
                long run, do we need to maintain some clearance? We are
looking at 5mil
                spaces, by the way.

                Are traces in the same bus "hostile" to each other?
                (Okay, I know I should know this, but I don't, ok?)