[SI-LIST] Re: Routing Parallel vs. Paralell
- From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
- To: <pcbjack@xxxxxxxxx>
- Date: Sat, 16 Sep 2006 11:26:41 -0700
I think you're asking a very valid question - one which I've answered
before. In my case, I found that the crosstalk induced on the adjacent
layer of a dual stripline was approximately twice that of traces on the
same layer. But, that was for a very specific set of laminate and trace
thicknesses, etc. (which I won't go into).
Unfortunately, it's complicated enough (so many variables) that it
doesn't lend itself to any "rule of thumb". An analysis using a field
solver really is required to compare your specific topologies. =20
I'm also afraid that an SI engineer without access to a good 2-D field
solver (including crosstalk analysis) is going to be extremely limited
in providing data for a substantial portion (if not the majority) of the
"what-if" questions they will be asked.=20
P.S.
You get my vote for "Subject heading of the year"! It made me grin
every time I saw it...
Disclaimer:
The content of this message is my personal opinion only and although I
am an employee of Intel, the statements I make here in no way represent
Intel's position on the issue, nor am I authorized to speak on behalf of
Intel on this matter.
Jeff Loyer
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
On Behalf Of Jack Olson
Sent: Saturday, September 16, 2006 9:57 AM
To: Ken Cantrell
Cc: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Routing Parallel vs. Paralell
Okay, I have used up more than my fair share of "the resources" here,
(so I will go back to "lurker mode" for awhile) but I just wanted to
thank
everyone for all the help.
With the gentle guidance of a few kind souls I realize that I was having
a total bonehead brain freeze yesterday, but I just couldn't grasp it.
It all started when I had an engineer obsessing over a few short layer-
to-layer overlaps, and then I started teasing him about being more
concerned with the little overlaps and totally ignoring long parallel
runs.
THEN I started wondering if I was missing something, so I came here.
Thanks you all for responding, I really appreciate it.
Jack (aka "the not-so-new guy who still regularly feels like the new
guy")
-=3D-=3D-=3D-
On 9/14/06, Ken Cantrell <Ken.Cantrell@xxxxxxxxxxxxxxxx> wrote:
>
> Jack,
> As Steve pointed out a field solver is required for that type of
analysis.
> From a MATH viewpoint, coupled line theory is not simple, and the
> equations
> are relatively inaccurate at today's geometries. Two texts that
explain
> the
> math are
> Analysis of Multiconductor Transmision Lines, Clayton Paul
> Networks and Devices Using Planar Transmissions Lines, Franco Di Paola
> Ken
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx
> [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Jack Olson
> Sent: Thursday, September 14, 2006 8:30 AM
> To: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Routing Parallel vs. Paralell
>
>
> I got a MATH question I don't know how to solve...
> I want to know the difference between running traces
> parallel on the same layer (side by side) compared
> to running them on different layers right on top of
> each other (broadside).
>
> I know won't be a simple answer,
> so I will provide a simple example:
>
> Say I am using 6mil traces with 6mil clearances on
> layers that are 6mil apart using half ounce copper
> (which is nearly .6mils) and both layers are internal.
>
> What distance can I route side by side and get the
> same coupling as if I had routed them broadside?
>
> So I want a simple thing to remember that says
> something like, "traces routed 1 inch in parallel will
> couple the same amount as traces routed .2 inches
> broadside (layer to layer)
>
> Does anyone know how to make my rule-of-thumb?
> and if I change to 1oz copper, will the rule double?
>
> onward thru the fog,
> Jack
>
>
>
>
------------------------------------------------------------------
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 FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at: =20
//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
=20
------------------------------------------------------------------
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 FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
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:
