Re: How inaccurate is a 555 or 7555 REALLY?


<bill.slowman@xxxxxxxx>


10MHz crystals are sold with a +/-0.1% absolute tolerance.


** By whom ?

All the ones I see have 20, 30 or 50 ppm accuracy.

Equates to 0.002%, 0.003% or 0.005 % tolerance.



32768Hz
watch crystals aren't that good (if I remember my Farnell catalogue
corectly.


** They have 20 ppm @ 25C accuracy too, I'm afraid.




...... Phil




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