RE: [SI-LIST] : What's your favourite Screwy SI Concept?

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From: cadpro2k@DACafe.com
Date: Fri Jan 14 2000 - 16:08:10 PST


Man, you guys blow me away! You want data? Check out UltraCAD and see
what Doug Brooks says and has data to back it up. I have NEVER seen any
data dissproving 90 degree traces. It's always heresay! Some days are
just better than others!

Mitch

---------Included Message----------
> Date: Fri, 14 Jan 2000 11:10:25 -0800
> From: "Jian Zheng" <jian@zeland.com>
> Reply-To: <si-list@silab.eng.sun.com>
> To: <si-list@silab.eng.sun.com>
> Subject: RE: [SI-LIST] : What's your favourite Screwy SI
Concept?
>
> Hi:
>
> In fact, the flow of electric current is very similar to the flow
of water
> current.
>
>
> | |
> | |B______
> |
> |A__________
>
> When you have a bend, the current will take a short cut at the
corner B. The
> current at the corner A will be slowed down. For the electric
current, the
> slow down at corner A will create reflection from the corner. The
short cut
> at the corner B will make the electric path shorter than measured
along the
> center line. For standard PCB, the reflection from the corner is
very small.
> However, I understand that the electrical length is very
important in clock
> synchrinization. Accumulation of the shortening of electrical
path at angles
> may have effect to SI. Thanks!
>
> Best regards,
>
>
----------------------------------------------------------------------------
> ------------
> Jian-X. Zheng, Ph.D
> Zeland Software, Inc., 39676 Mission Blvd., Fremont, CA 94539,
U.S.A.
> Tel: 510-797-8109, Fax: 510-797-8241, Web: http://www.zeland.com
>
----------------------------------------------------------------------------
> ------------
>
> > -----Original Message-----
> > From: owner-si-list@silab.eng.sun.com
> > [mailto:owner-si-list@silab.eng.sun.com]On Behalf Of Jeff
Seeger
> > Sent: Friday, January 14, 2000 10:05 AM
> > To: si-list@silab.eng.sun.com
> > Subject: Re: [SI-LIST] : What's your favourite Screwy SI
Concept?
> >
> >
> > Tom Dagostino wrote:
> > >
> > > Bending a wire keeps a uniform cross section. Putting a
corner
> > in a trace
> > > adds extra C at the corner from a larger area.
> > >
> > And herein lies the arguement, I believe.
> >
> > Perhaps those who argue against "right angles" envision a
> > geometry where the line has a squared corner both on the
> > inside of the elbow and the outside.
> >
> > I would wager that those who claim no material effect are
> > working with the usual CAD system/photoplotter geometry of
> > a squared corner inside the elbow and a radiused one on the
> > outside.
> >
> > An attempt at ascii art:
> >
> > "Right Angle" "Standard Practice"
> >
> > \ \ \ \
> > \ \ \ \
> > > > > )
> > / / / /
> > / / / /
> >
> > HTH,
> > --
> >
> > Jeff Seeger Applied CAD Knowledge
Inc
> > Chief Technical Officer Tyngsboro, MA
01879
> > jseeger "at" appliedcad "dot" com 978 649
9800
> >
> > **** To unsubscribe from si-list: send e-mail to
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> >
> >
>
>
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