I've had a number of cases where an IC vendor did a die shrink on an IC without rescaling the pin drivers. Even though the IC ran at the same speeds, the edges were much sharper leading to problems at higher harmonics. I would suspect that a number of ICs in your system have undergone die shrinks. The IC vendors are always looking for ways to get more chips out of a single wafer.
Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com<mailto:ted.eck...@microsoft.com> The opinions expressed are my own and do not necessarily reflect those of my employer. From: McInturff, Gary [mailto:gary.mcintu...@esterline.com] Sent: Tuesday, May 29, 2012 10:16 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Statute of limitations Is there any time limit on how long a test result is valid for an EMC test - if the product hasn't changed. CB reports have a 3 year shelf life, after which the various CB participants are obligated to take the reports on face value and could require inspection or retest, but I don't know if the same is true for EMC test when meeting the EU directives. Actually I guess the requirement for a CB update every three years isn't truly a requirement for meeting the directives either. The CB report is a tool to help show conformity. Bottom line the last EMC test was in 2004, and the clock speeds are pretty low - 12 MHz, so I don't think even the new upper frequency test range requirements of EN55022 affect the results. I'm inclined to test, the customer is not. Gary McInturff Reliability/Compliance Engineer Esterline Interface Technologies Featuring ADVANCED INPUT, MEMTRON, and LRE MEDICAL products 600 W. Wilbur Avenue Coeur d'Alene, ID 83815-9496 Office:208-635-8306 Cell: 509 868 2279 Toll Free: 800-444-5923 X 1238 gary.mcintu...@esterline.com<mailto:brian.s...@esterline.com> www.esterline.com/interfacetechnologies<http://www.esterline.com/advancedinput> Technology, Innovation, Performance... - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org<mailto:emc-p...@ieee.org>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net<mailto:emcp...@radiusnorth.net>> Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald <dhe...@gmail.com<mailto:dhe...@gmail.com>> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
