Lee, I like and agree with your approach in principle, and whenever circumstances allow, this is the proper way of solving things. I think, however, the question is triggered by situations, when life does not allow us to follow this procedure. Unless there is data available from the past (and this is what the question was looking for) either by the person facing the problem (meaning that the person had the time and resources to do the detailed homework before the question came up) of from other sources, like publications, SI-LIST, etc, answering all (or just a few) of these five questions, would take much longer than what is allowed by a typical project cycle. Regards, Istvan Novak SUN Microsystems Lee Ritchey wrote: > Gilles, > > I understand how difficult it is to find articles on this topic. > > Perhaps it is fair to turn the question around for those adamant about > splitting grounds. > > The proponents of this practice need to answer these questions for you. > > 1. Is there a problem that needs to be solved? > 2. What, exactly is the problem? > 3. Does the proposed solution solve the problem? > 4. Does the proposed solution not create any new problems? > 5. Is there no better solution? > > In almost all cases, things stop at 1, becasue the proponents of this > practice are solving an imaginary problem. > > Lee > > > >> [Original Message] >> From: Gilles Aminot <gilles.aminot@xxxxxxxxxxxxxxx> >> To: <si-list@xxxxxxxxxxxxx> >> Date: 9/21/2007 2:39:55 PM >> Subject: [SI-LIST] Need technical ammunition for switching to single >> > ground plane ! > >> Hi Everyone, >> >> I'm working on a new design and would like to eliminate split ground >> planes. In the past we've always split the analog ground plane (for >> analog audio circuits and codecs) and joined it at one location >> (sometimes shorting or through an inductor). I've read lot's of postings >> on this group explaining good reasons not to split ground planes, but >> the only real supporting documentation I have seen is the following >> article: >> http://www.analog.com/analog_root/static/pdf/raq/RAQ_groundingADCs.pdf >> <http://www.analog.com/analog_root/static/pdf/raq/RAQ_groundingADCs.pdf> >> and it does not provide much depth.. >> >> I have been meeting some resistance to eliminating the split ground >> planes and I am looking for technical articles showing the advantages of >> using a single ground plane in designs with mixed high speed digital and >> sensitve analog circuits. I keep bumping my head against datasheets or >> articles that say analog & digital grounds should be separated (such as: >> http://www.ultracad.com/articles/planesplits.pdf), which makes it >> difficult to convince my peers that changing our approach is the way to >> go. Can anyone share or point me to articles which may help me plead my >> case. I would also appreciate if anyone could share some real life >> experiences of going from split to single ground plane. >> >> Kindest Regards, >> Gilles Aminot, P.Eng >> Hardware Design Engineer >> >> Librestream Technologies Inc >> Unit 200 - 55 Rothwell Rd >> Winnipeg MB. Canada >> R3P-2M5 >> PH: 204-487-0612 Ext 218 >> FX: 204-487-0914 >> >> >> ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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