Matt Ettus wrote: > I was just investigating this very issue. It seems that every program > you use to compute these impedances comes up with different answers, > sometimes wildly different. Anyone have a free program they trust > with this sort of thing? > > Matt > > On 3/14/07, Dr Bruce Griffiths <[EMAIL PROTECTED]> wrote: > >> Tom Clark, K3IO wrote: >> >>> I just stumbled on an excellent tutorial on low-noise clocks -- >>> National Semiconductors free downloadable "[1]Clock Conditioner >>> Owner's Manual". This 88 page document is a 3.7 MB PDF. >>> 73 de Tom, K3IO >>> >>> References >>> >>> 1. >>> http://www.national.com/appinfo/interface/files/clk_conditioner_owners_manual.pdf >>> _______________________________________________ >>> time-nuts mailing list >>> [email protected] >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> >>> >>> >> Tom >> >> Not bad except they give inaccurate formulae for stripline and >> microstripline characteristic impedance. >> Will these inaccurate formulae ever go away? >> They've been around since the 1970's. >> When with the trace widths and board thickness then in use the accuracy >> wasn't too bad. >> However they are not very useful for modern PCB design. >> >> Bruce >> >> _______________________________________________ >> time-nuts mailing list >> [email protected] >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> >> > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > Matt
The formulae given in Johnson and Graham's "High speed Digital Design" are reliable. However there's no substitute for measurement to check your calculations, Bruce _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
