robi, I do a bit of controlled impedance work in printed flex cabling and I've found the Polar calculator to be very accurate. We've realized flex cables within 5% of predicted at 110 ohm. Your fabricator may have a calculator and know their processes, which also have an effect. It's quite expensive, but is available over FlexLM for about $20 US/hour . All impedance calculators are approximations and you will get the best calculator results with edge coupled as opposed to broadside coupled. John
robi wrote: >Hello Forum > >My task: >"Differential Pair" routing to 100 Ohm impedance. > >My Question: >Where would I find a, "proven to be right" calculator. >By, proven to be right - has anyone used a calculator where the >assembled board did actually measure the correct impedance. > >My doubts: >I've run several calc. with different, freely available tools but got >up to a 45% difference in calc. impedance. > >Any help would be appreciated. >If you may have a proven calculation tool, maybe I can send you the >data and you do me a favour in running the calc for me. > >Please don't send any links to websites, unless you've used it and >it's been proven to show the right impedance - >I've been on Google and Yahoo - that's why I can say - calc. differ >quite badly. >Cheers >Robi > > > > > >____________________________________________________________ >You are subscribed to the PEDA discussion forum > >To Post messages: >mailto:[email protected] > >Unsubscribe and Other Options: >http://techservinc.com/mailman/listinfo/peda_techservinc.com > >Browse or Search Old Archives (2001-2004): >http://www.mail-archive.com/[email protected] > >Browse or Search Current Archives (2004-Current): >http://www.mail-archive.com/[email protected] > > > > > -- ######################################################### John M. Cardone http://www.jmcdesignservices.com JMC Design Services MailTo:[EMAIL PROTECTED] P.O. Box 397 office: 530-436-2216 Grenada, CA. 96038 cell: 805-796-0787 ######################################################### ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
