Hi The EFC pin *might* have a bypass cap on it. If you drive it with an op-amp an isolating resistor might be needed. If so, a couple hundred ohms is likely enough to stabilize the op-amp.
In a closed loop / control loop setting, the noise on the EFC will be whatever the loop generates. As long as you stay with good quality op-amps and low impedances in your filters, things should be plenty quiet. Things like EFC range, output frequency, phase noise, and intended use / circuit would be needed to come up with more specific information. Bob On Sep 4, 2014, at 10:53 AM, Dan Kemppainen <[email protected]> wrote: > Hi all, > > I have an PTI OCXO. The trimming voltage is two pins, with a maximum of > 6.8VDC across the pins. They specify using a 20K pot as the adjustment > mechanism. However, I hope to use this thing in a closed loop, and will > be driving it with an active device. > > What got me thinking is if the frequency trimming is simply a varactor > across some part of the circuit. I wonder how susceptible is the input > to driving impedance and noise? > > Any suggestions on how to drive this input, or what to watch out for. > I'm sure every OCXO is different. Are there any general precautions to > take? > > Thanks, > Dan > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
