Crystal oscillator start-up times

[zirissjk]

Hi,

I'm new to electronics forums and only a beginner circuit builder. I'm looking to find the start-up times of various crystal oscillators, primarily OCXO stratum class. I know it is difficult information to find due to the random start nature of crystal oscillators but still need to find min/max start times and was wondering if anyone here can point me in the right direction. I've spent hours google searching and scanning scholarly articles with little luck. If anyone can help many thanks in advance.

 

[keith1200rs]

A bit of information here: https://www.maximintegrated.com/app-notes/index.mvp/id/5265 although maybe you have already found that. I am not sure there is a "minimum" time - if you are lucky (i.e. a power on glitch or noise of just the right amplitude or phase) it will start quickly. The calculations for startup time will generally be looking for the time by which the oscillator can be guaranteed to have started.

Keith.

 

[zirissjk]

Thank you Keith.
It looks like I found the answer I'm looking for in that paper. Now to understanding it

 

[pstuckey]

I think the key question is how close do you need to be to final frequency? Most manufacturers will give you a spec for how long it will take for the OCXO to settle to within some percentage of specified frequency. For instance, the OX-203 will achieve +-10 ppb of final frequency within 5 minutes. If this is not specified, you could monitor power consumption to get a rough idea of stabilization time.