This is actually an interesting question. I have several impedance calculators/field solvers a) X-Flux from GE; b) The one in the now unsupported AMPPREDICTOR c) The field solver in HSPICE d) CITS25 from Polar; e) The one in SpecctraQuest 14.2 There are dozens more out there and they mostly give different values for the same geometry inputs, especially with differential lines. Some are close enough that it doesn't matter while others are pretty far apart. Comparing the tool predictions with the geometry the board houses use to build the boards to achieve the desired impedance and the actual measured board impedances also results in some widely differing values. In general, the finished impedances are within 10% of the target but one board house will be at the high end while the next one may be at the low end for the first builds. Kai Keskinen Signal Integrity Advisor Solectron Technical Center 425 Legget Drive, Kanata, ON K2K 2W2 kaikeskinen@xxxxxxxxxxxxx www.solectron.com -----Original Message----- From: Hora Abu [mailto:arageeb@xxxxxxxxx] Sent: Friday, September 13, 2002 9:08 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Trace resistance inductance Guys, Does any one know of an accurate calculator for for trace resistance and inductance based on the trace geometry and the hight from reference plane. Ahmed --------------------------------- Do you Yahoo!? Yahoo! News - Today's headlines ------------------------------------------------------------------ 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 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 ------------------------------------------------------------------ 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 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