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Re: gEDA-user: pcb, howto partition power planes?
No the first attempt was a cut and paste that didn't bring the url with
it though an html filter would have removed it. The second and third
attempts I was responding only too myself. Good thing too as I was
getting frustrated with how my email tool automatically breaks lines
into pieces. And the urls are convoluted.
Steve Meier
On Thu, 2008-10-30 at 19:14 -0700, Steven Michalske wrote:
> Were you trying to format them with HTML?
>
> I bet the HTML filters on the mailing list were cutting out the links.
>
> On Oct 30, 2008, at 2:44 PM, Eric Winsor wrote:
>
> > Steve,
> >
> > I don't see these other attempts.
> >
> > Eric Winsor
> >
> > Steve Meier wrote:
> >> Dave,
> >>
> >> No I struggled three times to get usable url's so go down a couple
> >> more
> >> of my attempts and then you will have to take the line breaks out
> >> of the
> >> ultra long url but you can get there.
> >>
> >> Steve Meier
> >>
> >>
> >> On Thu, 2008-10-30 at 16:29 -0400, Dave McGuire wrote:
> >>
> >>> I don't see any URLs in there..
> >>>
> >>> -Dave
> >>>
> >>> On Oct 29, 2008, at 6:08 PM, Steve Meier wrote:
> >>>
> >>>> I went looking to see if the Analog Device book was available
> >>>> electronically. Here are the links.
> >>>>
> >>>>
> >>>> Steve Meier
> >>>>
> >>>>
> >>>> High Speed System Applications Table of Contents
> >>>>
> >>>>
> >>>>
> >>>> High Speed System Applications Section 1: High Speed Data
> >>>> Conversion
> >>>> Overview
> >>>>
> >>>>
> >>>>
> >>>> High Speed System Applications Section 2: Optimizing Data Converter
> >>>> Interfaces
> >>>>
> >>>>
> >>>>
> >>>> High Speed System Applications Section 3: DAC, DDS, PLL's, and
> >>>> Clock
> >>>> Distribution
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> High Speed System Applications Section 4: PC Board Layout and
> >>>> Design
> >>>> Tools
> >>>>
> >>>>
> >>>>
> >>>> On Tue, 2008-10-28 at 13:44 -0700, Steve Meier wrote:
> >>>>
> >>>>> I won't argue this point. I will refer every one to an Analog
> >>>>> Device
> >>>>> publication "High Speed System Applications" copyright 2006
> >>>>> ISBN-10:
> >>>>> 1-56619-909-3 or ISBN-13: 978-1-56619-909-4
> >>>>>
> >>>>> In particular if you get a copy of this book (and they gave me
> >>>>> mine)
> >>>>> look at pages 4.15 and 4.16
> >>>>>
> >>>>> There AD recommends connecting both of the A/D grounds "digital"
> >>>>> and
> >>>>> "analog" to the analog ground plane "this is because it causes
> >>>>> less
> >>>>> problems for the relatively small amount of digital return current
> >>>>> to be
> >>>>> returned through the analog ground than it would to connect the
> >>>>> converter to the much noisy digital ground.
> >>>>>
> >>>>> There is a lot more talked about then just that one blurb.
> >>>>>
> >>>>> Steve Meier
> >>>>>
> >>>>>
> >>>>>
> >>>>> On Tue, 2008-10-28 at 11:22 -0700, Joerg wrote:
> >>>>>
> >>>>>> Stefan Salewski wrote:
> >>>>>>
> >>>>>>> Sometimes it is necessary/recommended to partition (separate)
> >>>>>>> power or
> >>>>>>> ground planes, i.e. for ADC or DC/DC-Converters, see page 16 and
> >>>>>>> 17 in
> >>>>>>>
> >>>>>>> http://focus.ti.com/lit/ug/slwu028c/slwu028c.pdf
> >>>>>>>
> >>>>>>> We can do this in pcb program with (adjoining) polygons.
> >>>>>>> Disadvantage is, that if we change the size of one of the
> >>>>>>> polygons we
> >>>>>>> have to manually adjust the other sizes. A other method may be
> >>>>>>> so divide
> >>>>>>> a large polygon by copper clearing traces (with trace width
> >>>>>>> zero).
> >>>>>>>
> >>>>>>> This is related to my question from
> >>>>>>>
> >>>>>>> http://archives.seul.org/geda/user/Sep-2008/msg00387.html
> >>>>>>>
> >>>>>>> but not identical.
> >>>>>>>
> >>>>>>> What is the best way to handle this?
> >>>>>>>
> >>>>>>>
> >>>>>> I can't speak to that but just one word of caution: In my 20+
> >>>>>> years in
> >>>>>> engineering I have yet to see one case where splitting a ground
> >>>>>> plane
> >>>>>> under high-speed ADCs has worked. Regardless of what application
> >>>>>> notes
> >>>>>> say. Usually it didn't work, lots of noise. Or it kind of
> >>>>>> worked but
> >>>>>> fell apart the instant somebody whipped out a GSM cell phone or
> >>>>>> BlackBerry.
> >>>>>>
> >>>>>> Myself, I never spilt a ground place. OTOH the industry
> >>>>>> practice of
> >>>>>> splitting planes is providing part of my income :-)
> >>>>>>
> >>>>>> The only time I split is where required for safety, for example
> >>>>>> patient
> >>>>>> isolation per 60601 (ECG, ultrasound etc.).
> >>>>>>
> >>>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> geda-user mailing list
> >>>>> geda-user@xxxxxxxxxxxxxx
> >>>>> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
> >>>>>
> >>>>
> >>>> _______________________________________________
> >>>> geda-user mailing list
> >>>> geda-user@xxxxxxxxxxxxxx
> >>>> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
> >>>>
> >>>
> >>
> >>
> >>
> >> _______________________________________________
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> >>
> >
> >
> >
> >
> > _______________________________________________
> > geda-user mailing list
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> > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
>
>
>
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