Hi Spero.

What would be easiest solution if you use crystals with initial 50 ppm
and temperature deviation +/- 30 ppm ( generic ones AT cut ) to calibrate
it with 10 ppm initial and +/- 10 ppm over -40 +85 *C temperature ? :)

I guess it is possible ?


WBR Dmitry.



Spehro Pefhany wrote:
> 
> >OK Sherlock, you convinced me, thats the problem. But what's the
> >solution?
> 
> Use a more tolerant crystal, a crystal with lower Rs, lower the
> Vdd, add a series resistor, lower the load capacitor values.
> All have side effects (the last three will prevent the oscillator from
> starting if taken to extremes).
> 
> The easiest solution, if accuracy isn't much of a concern, is to slap a
> 20MHz resonator in there, as, I think, you suggested earlier. More rugged,
> starts faster, accurate enough for reliable RS-232/485 communication, and
> really very good typical temperature stability. But not every application
> can tolerate +/-0.5% or whatever error.
> 
> Best regards,
> 
> Spehro Pefhany --"it's the network..."            "The Journey is the reward"
> speff@interlog.com             Info for manufacturers: http://www.trexon.com
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