); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY It's been my experience that most low-dropout regulators are worse than the older generation high-dropout, not only for noise but also for ripple and transients rejection, probably because of the unfavorable topology of a power PNP transistor as the pass element. It has low gain and low FT, and yet the circuit is naturaly unstable unless particular decoupling caps are used, so compromises in the loop response have to be made, resulting in high noise. It's possible the reference internally is quiet, but the regulator itself is bad.
I guess for most applications it's OK, so unless pressed by the market, the vendors will do what sells. Didier > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths > Sent: Tuesday, November 13, 2007 12:24 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] paralleling regulator redux > > Didier Juges wrote: > > The point of these improved acuracy regulators is that in > most cases, > > trace resistance (the PWB) is sufficient as a ballast, so > there is no > > need for a separate component (if you have enough room for > the trace > > :-) > > > > Didier KO4BB > > > > > But they are still noisy. > Note some plots are for 1V output. > > bruce > > _______________________________________________ > 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.
