crystal tolerance
Looking at some 120MHz and 20MHz crystals available:
Frequency Tolerance: ± 50ppm (this is for both 20MHz and 120MHz crystals)
So the 20MHz crystal could be off by 1000hz and the 120MHz one could
be off by as much as 6000hz (either + or - of course). Is my interpretation
of ± 50ppm accurate?
A 20MHz crystal would have the range of 19.999MHz to 20.001MHz.
So a 120MHz crystal would have a range of 119.994MHz to 120.006MHz.
The entire range is still within the general frequency range we want.
Seeing that the 20MHz still has some deviation overall, even if not as
much as a 120MHz crystal, it still has deviation meaning according to
Mike's diagram, the water still splits from this and the water would appear
not to care about the 20MHz crystal deviation.
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edit: And, this depends on what deviation means. If the tolerance indicates
how much off from the rated MHz it is and if it is off, the frequency stats
consistent but could be off from 20MHz or 120MHz permanently.
Or does the crystal's frequency roam around while running deviating from
the rated spec as it is being used as a trigger signal.
Looking at some 120MHz and 20MHz crystals available:
Frequency Tolerance: ± 50ppm (this is for both 20MHz and 120MHz crystals)
So the 20MHz crystal could be off by 1000hz and the 120MHz one could
be off by as much as 6000hz (either + or - of course). Is my interpretation
of ± 50ppm accurate?
A 20MHz crystal would have the range of 19.999MHz to 20.001MHz.
So a 120MHz crystal would have a range of 119.994MHz to 120.006MHz.
The entire range is still within the general frequency range we want.
Seeing that the 20MHz still has some deviation overall, even if not as
much as a 120MHz crystal, it still has deviation meaning according to
Mike's diagram, the water still splits from this and the water would appear
not to care about the 20MHz crystal deviation.
-------------
edit: And, this depends on what deviation means. If the tolerance indicates
how much off from the rated MHz it is and if it is off, the frequency stats
consistent but could be off from 20MHz or 120MHz permanently.
Or does the crystal's frequency roam around while running deviating from
the rated spec as it is being used as a trigger signal.
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