[SI-LIST] Re: XAUI

Lee, yes and that is a point that we agree about.  I just didn't want your 
reply to be interpreted as advocating either BS or EC particularly BS 
across PP, and even worse across thin PP.

Steve.
At 07:20 PM 12/22/2005 -0800, Lee Ritchey wrote:
>Steve,
>
>Do you mean by PP preperg?  If so, that would infer what is often called
>broadside coupling or one over the top of the other.  If that is what you
>mean by this, it's about the worst way there is to route a diff pair and I
>would never want to do that.  It is really a tough one to get right.
>
>Lee W. Ritchey
>Speeding Edge
>P. O. Box 2194
>Glen Ellen, CA 95442
>Phone- 707-568-3983
>FAX-    707-568-3504
>
>I just used the energy it took to be angry to write some blues.
>Count Basie
>
>
> > [Original Message]
> > From: steve weir <weirsi@xxxxxxxxxx>
> > To: <leeritchey@xxxxxxxxxxxxx>; Ravindra Johari
><Ravindra.Johari@xxxxxxxxxxxxxxxxxx>; <si-list@xxxxxxxxxxxxx>
> > Date: 12/22/2005 6:38:13 PM
> > Subject: Re: [SI-LIST] Re: XAUI
> >
> > Lee, I agree that loosely coupled usually brings fewer issues to deal
>with
> > than tightly coupled, making it a safer default recommendation.  For
> > loosely coupled, I would avoid broadside coupling including tandems,
> > particularly across PP.  If B/S coupled across PP, the registration, and
> > therefore coupling can vary quite a bit, especially for narrow traces.
>If
> > the PP is thin, it just makes it worse.
> >
> > Steve.
> > At 02:17 PM 12/22/2005 -0800, Lee Ritchey wrote:
> > >Actually, neither.  Coupling doesn't have any benefit.  If you can spread
> > >the traces out so there is no coupling, you've got the best geometry.
>Real
> > >world, you can't do this and route a PCB, so route side by side with as
> > >much separation as your topology will allow.  Then adjust trace widths to
> > >give you 100 ohm diff impedance.
> > >
> > >Lee W. Ritchey
> > >Speeding Edge
> > >P. O. Box 2194
> > >Glen Ellen, CA 95442
> > >Phone- 707-568-3983
> > >FAX-    707-568-3504
> > >
> > >I just used the energy it took to be angry to write some blues.
> > >Count Basie
> > >
> > >
> > > > [Original Message]
> > > > From: Ravindra Johari <Ravindra.Johari@xxxxxxxxxxxxxxxxxx>
> > > > To: <si-list@xxxxxxxxxxxxx>
> > > > Date: 12/22/2005 11:19:44 AM
> > > > Subject: [SI-LIST] XAUI
> > > >
> > > >
> > > > Hello Gurus!!
> > > >
> > > >
> > > >
> > > > Which is a better coupling for running a differential pair at XAUI
>Speeds
> > > > i.e at 3 Gbps..
> > > >
> > > >
> > > >
> > > > Is it Edge coupled stripline or Broadside coupled stripline..
> > > >
> > > > What kind of constraints can I face with these?
> > > >
> > > >
> > > >
> > > > Thanks!
> > > >
> > > > Ravi
> > > >
> > > >
> > > >
> > > >
> > > >
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