Hi Part of the problem is radiated / mag coupled spur energy. One of the things that makes the fancier switchers more friendly is that they can contain this better.
Bob > On Mar 10, 2019, at 12:10 PM, jimlux <jim...@earthlink.net> wrote: > > On 3/10/19 8:58 AM, Richard (Rick) Karlquist wrote: >> Check out the LT3045-1. > Ive used the LT3042 in a space application, it is basically the same thing > with lower output current. The really great thing is that the rejection > extends up to 10 MHz. > > > > It is an ultra low noise (2nv) linear >> regulator with very high PSRR that has a 1 MHz bandwidth. >> The -1 version can control an external switcher (or linear) >> regulator ahead of it, where the voltage drop across the >> LT3045-1 can be set to, say 1V, and the front end supply >> output voltage automatically is 1V above the LT3045-1 >> output voltage. > > I didn't know about the -1 version.. I'll have to take a look. > > > > It has 120 dB PSRR at 120 Hz. You >> can buy an eval board for it. Multiple LT3045's can be >> paralleled for additional current handling. If the switcher >> is of the isolated type, you have galvanic isolation for >> the ultimate OCXO performance. >> I think the vendor really got this right. > > Yes, indeed > > > So my notional "run noise sensitive electronics from ubiquitous 5V USB" is > "5V to TBD V boost converter (in a module from someone like Cui, most > likely)" followed by a LT304X. > > I will have to look into the "LT3045-1 feeds back a control signal".. > > And as Bob notes - layout is critical (isn't it always) - but I must confess, > the first one's going to be haywired with double stick foam tape for mounting. > > > >> Rick N6RK > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.