Hi My *guess* is that your 1Hz data may be as much from ambient changes as from the op amps themselves. No data to back that up on these specific parts, just a guess.
Bob On Apr 17, 2012, at 7:28 AM, Bruce Griffiths wrote: > Not yet, I just used the pair of TI evaluation boards which I obtained for > another project. > > I intend to mount the various components (splitters, 180 degree hybrids etc) > on a thick aluminium plate to improve the mechanical and thermal stability of > the system. > > Bruce > > Bob Camp wrote: >> Hi >> >> Did you do any temperature stabilization on the op amps? >> >> Bob >> >> On Apr 17, 2012, at 5:25 AM, Bruce Griffiths wrote: >> >> >>> Subsequent measurements using an improved technique has allowed the true >>> flicker phase noise characteristics of a pair of OPA653 opamps to be >>> determined. >>> >>> Opamp >>> Gain 1x (6db folled by 6 db attenuator consisting of a 50 ohm resistor >>> in series with the output of the opamp and the 50 ohm load resistor) >>> Signal input level: + 10dBm >>> >>> OFFSET Opamp PN (dBc/Hz) Measurement system PN (dBc/Hz) >>> >>> 1 -148 -161 >>> >>> 10 -161 -172 >>> >>> 100 -164 -177 >>> >>> 1000 -164 -179 >>> >>> Source: 10MHz low phase noise OCXO removed from a Thunderbolt amplified by >>> a QBH9816 amplifier. >>> >>> Conclusion: FET opamp PN in the flicker region can be quite low despite its >>> somewhat higher baseband flicker noise than that of some bipolar input >>> opamps. >>> >>> Bruce >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
