Hi At least in terms of voltage regulation (as opposed to noise), the -12V input on the TBolt is the *least* sensitive input on the TBolt. It’s issue is only in terms of PSRR. The internals of the unit take care of any drift or really low frequency stuff on the -12 input.
Bob > On Oct 21, 2016, at 9:14 AM, Nick Sayer via time-nuts <[email protected]> > wrote: > > Well, because it's easily an order of magnitude more expensive than a 7912. > $5 instead of 50¢ (Q:1). > > If it *matters*, then fine, but I am sensitive to cost efficiency in addition > to efficacy. > > If you put the board in a box in a stable temperature environment (which I'd > kind of assume you'd do if you cared about temperature stability generally), > then how far do you really have to go? > > Sent from my iPhone > >> On Oct 21, 2016, at 1:59 AM, Attila Kinali <[email protected]> wrote: >> >> On Fri, 21 Oct 2016 00:20:43 -0400 >> Scott Stobbe <[email protected]> wrote: >> >>> The bad side of a 7912 is in long-term stability and tempCo, the sample I >>> tested had at least a 150 ppm/degC tempCo, which is going to put a serious >>> lump/bump in the 10s tau to gps crossover point on an allan deviation plot. >> >> If the Thunderbolt ist most sensitive to the -12V input, why not use >> something like the LT3090? Its temperature coefficient is quite low >> in the order of a few ppm/°C around room temperature. Using a metal >> film resistor that should keep the output variations low as well. >> As added bonus, you get a very low output noise. >> >> And while you are at it, use three LT3090 for the positive supplies :-) >> >> Attila Kinali >> -- >> Malek's Law: >> Any simple idea will be worded in the most complicated way. >> _______________________________________________ >> 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. _______________________________________________ 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.
