Re: [SI-LIST] : The Flight-Time/SI Effects of Trace 'Tromboning'

Chris Heard/US/3Com (Chris_Heard/US/3Com%3COM@SMTP1.isd.3com.com)
9 Jan 98 10:14:45 EDT

Generally, separating the traces by 3 times the distance to the ground plane
will ensure no field coupling between the lines.

Chris

----- Previous Message ----------------------------------------------------

To: si-list @silab.Eng.Sun.COM @ SMTP1
cc:
From: Orville.Orr@COMPAQ.com ("Orr, Orville") @ SMTP1
Date: Thursday January 8, 1998 07:26 PM
Subject: [SI-LIST] : The Flight-Time/SI Effects of Trace 'Tromboning'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Has anyone investigated the effects of trace 'tromboning' (i.e.,
folding the trace to add length) on flight-time and signal integrity
in general. I'm interested in some rough rules-of-thumb on flight-time
increases/decreases given a fold with a length of 'x' and a distance
between the traces of 'y'. (The environment is current
state-of-the-art 100Mhz+ multi-layer boards). How much separation is
needed to eliminate any problems (assuming the problem is
significant).

Also, is this handled correctly in current simulators (such as Quad).

Thanks
Orville Orr
Compaq Computer Corp.
ECG - Enterprise Computing Group
Phone: (281) 518-8546
Fax: (281) 518-7445
Pager: (713) 765-9892
Email: orville.orr@compaq.com