Hish frequency dividers, improve stability?

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neazoi

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Hello I have a 17MHz oscillator divided down to 16 times using ttl.

Will the stability of the divided output signal be better than the original 17MHz, because of the division?

I have found that fine tuning of the divided signal is better. I.e. a greater range 17MHz oscillator is needed to tune to a lower range divided signal. So any 17MHz frequency instability will result to a less instability on the divided signal.
 

Obviously, the relative frequency error (e.g. in ppm) will be the same. Some frequency divider generated jitter is added, however.

There may be reasons to divide a crystal oscillator output for reference frequency generation though. E.g. reducing the crystal size.
 

The final frequency Q factor would become at the same proportion, but the absolute error in terms of frequency will be indeed divided by the same factor.
 

andre_teprom said:
The final frequency Q factor would become at the same proportion, but the absolute error in terms of frequency will be indeed divided by the same factor.
Click to expand...

Thank you, It is this absolute error the one I was concerned I guess.
The percentage of frequency variation due to crystal heating for example, will be the same in both HF and the divided LF. But the relative frequency variation will be less at LF.

For example if the crystal drifts by 10Hz at 10MHz, then when divided by 10, the drift will be devided by 10 too. This means that this 10Hz drifting at 10MHz will become 1Hz variation at 1MHz.
Am I getting this right?
 

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