[time-nuts] Frequency Divider

Bruce Griffiths bruce.griffiths at xtra.co.nz
Fri Apr 3 11:34:50 UTC 2009


Since a good OCXO may have an AM noise floor well below -170dBc/Hz the
resultant output jitter due to AM noise using the amplitude, frequency,
bandwidth and threshold offset of my previous example would be 80fs rms
or less. Now unless one uses a logic family with sub 250ps intrinsic
jitter the effect of AM to PM conversion in this case is insignificant.
Even if one found such a logic family the threshold mismatch of such a
logic is likely to be much smaller than 1V further reducing the jitter
due to AM to PM conversion via the threshold mismatch.


Bruce



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