In a message dated 3/23/2004 5:46:25 PM Pacific Standard Time, arpad.muranyi@xxxxxxxxx writes: Would you mind if I asked you to expand on that a little more? What is it that makes you think "may not solve all of the known deficiencies"? ************* Arpad: The deficiencies mainly lie not in the current specification, but rather in the observed lack of careful attention to compliance with the recommended configuration and testing guidelines exercised by the vendors creating the model data. One of the difficulties I have found in examining and interpreting inconsistencies in the published IBIS models is the proper documentation of the test fixture parasitics (or in other cases, in the use of complete SPICE models for the generation of IBIS data). These parasitics must, of course, be properly de-embedded for accurate predictions. In the case of test measurements, I have often seen measurement sweep speed yield decent clamping (dc to low frequency) data, but the actual timing waveform for high frequency excursions is different because of the varying clamping diode capacitance affects. Additional cases were noted where the load and voltages conditions were not in accordance with standard IBIS conditions; therefore, the IBIS models could not be simply input to analysis software with the expectation of yielding accurate simulations. Lest we forget, there have been hundreds of comments posted over the last couple of years as to the dissatisfaction with many of the IBIS models available from vendors. I understand the sensitivity of all IBIS contributors to negative criticism, but please note the positive comments of my last contribution to the forum. I am not your enemy, nor am I adverse to using the efficiencies of (good) IBIS models as ably pointed out by Scott McMorrow earlier. Your colleague, Mike Michael L. Conn Owner/Principal Consultant Mikon Consulting *** Serving Your Needs with Technical Excellence *** ------------------------------------------------------------------ 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: http://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 List technical documents are available at: http://www.si-list.org List archives are viewable at: http://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