I have never seen a reference like that, but looking at it from the other
way, if you know the rise time and the distance between two traces (and to
the plane) you can calculate the crosstalk in dB for any parallel length.

Doug Brooks wrote an excellent calculator for this and you can get it at:
http://www.ultracad.com/calc.htm <http://www.ultracad.com/calc.htm>

Look for ULTRA_CT.ZIP

Good Luck,
Jack

                -----Original Message-----
                From:   Chris Robertson
[mailto:[log in to unmask]]
                Sent:   Monday, December 06, 1999 7:13 AM
                Subject:        Does anyone

                Does anyone have a plain formula that determines the
spacing/parallelism per
                frequency?

                i.e.. 1kHz, spacing; 10mil min, parallel; 10 mil max?

                Or is there a schedule/chart defining the relationship?

                Chris Robertson
                Senior Designer
                Lockheed - Martin Services, Inc.
                [log in to unmask]
                Ph/Fax (256) 722-2626
                ICQ# 13541566