On Aug 21, 2006, at 5:10 AM, Stuart Brorson wrote:
For your furnace controller, you probably won't see any difference between 1.0uF and 0.1 uF; either one will work for you. It's not necessarily in the same class as the GHz server motherboards or 10 GHz router boards that the SI gurus argue about.
It's not the *application* that matters: it's the *parts*! A chip capable of 500 MHz operation needs layout and bypassing appropriate to that speed. Otherwise, you're asking for double clocking, oscillation, crosstalk, etc. This can be a real problem with specialized aerospace chips (so-called "high reliability". Yeah right...), where things like clock rates are grossly derated on the spec sheet already, and you can be burned by things that are a *lot* faster than you expect. I've seen this cost millions of dollars when at the last moment it was found that the circuit didn't work cold, because a chip ran too fast for its bypass arrangements...
John Doty Noqsi Aerospace, Ltd. [EMAIL PROTECTED] _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
