[SI-LIST] Re: Diff.Pairs
- From: MikonCons@xxxxxxx
- To: chris.cheng@xxxxxxxxxxxx, mchin@xxxxxxxxx, si-list@xxxxxxxxxxxxx
- Date: Mon, 13 Oct 2003 18:19:25 EDT
Hi, Chris:
I admired your comments and the associated question you posed. If you caught
my comment on this subject sent a few minutes ago, you will see that there is
no way I would split pairs to different layers (unless forced into using
broadside coupled pairs). My interpretation of Lee's comments was that he
occasionally uses the traces of a differential pair on totally separate layers
(i.e.,
as separate 50-Ohm traces). There was no mention (that I caught) of
broadside-coupled pairs, which is a workable solution, but has other design
tradeoffs.
Lee Richey and I do not appear to be on the same page.
Regarding "tightly coupled" traces: The degree of coupling tends to fall in
the 10-20% range; therefore, there is still considerable current implied in
the nearest image plane (but of course, with opposite polarity so the net
current is very small). I use tightly coupled traces with reasonable separation
from
adjacent pairs to a) minimize the net differential signal coupled into any
given pair, and b) minimize impedance variations caused by manufacturing
tolerances in the dielectric materials.
Mike
Michael L. Conn
Owner/Principal Consultant
Mikon Consulting
*** Serving Your Needs with Technical Excellence ***
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
