Hi All, My article is a little late this month due to travel, but it is done now and many of you may find the data/discussion/audio file interesting. A signal that passes through multiple layers, especially from the top layer to the bottom layer of a four layer board, can see significant impairment. An ESD example to illustrate the magnitude of the problem is given. Abstract: Printed wiring board, PWB, signal paths must often change layers in a board stackup. Under some conditions this can cause problems. An ESD example is used to illustrate the conditions where changing layers can cause problems. The link to the article is the drawing of a signal changing layers at the bottom of the home page at http://emcesd.com . There is also an audio discussion of this article on my podcast site: http://emcesd-podcast.com where the direct link to the article is: http://emcesd-podcast.com/2006/april/2006-0406.mp3 Can't download mp3 files? Download the following instead: http://emcesd-podcast.com/2006/april/2006-0406.dcs After download, change the extension from .dcs to .mp3 and the file will then be able to play on most computers. There are many such discussions on my podcast site. I have enough bandwidth for about a quarter of a million downloads per month of my mp3 technical podcasts so feel free to browse the site and listen to anything you find useful. Have a good month, Doug -- ------------------------------------------------------- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: doug@xxxxxxxxxx \ _ / ] \ _ / Website: http://www.dsmith.org ------------------------------------------------------- ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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