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@moria.seul.org >> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > > > _______________________________________________ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user -- Dave McGuire Port Charlotte, FL _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user