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 <att...@kinali.ch> wrote: > > On Fri, 21 Oct 2016 00:20:43 -0400 > Scott Stobbe <scott.j.sto...@gmail.com> 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 -- 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.
