[time-nuts] TADD-1 Design (was Re: Stepping up the output of an OCXO
Christopher Hoover
ch at murgatroid.com
Mon Feb 5 00:54:25 UTC 2007
> The TI regulators are, from my perspective extremely noisy, one can do
> much better at least for higher output voltages.
> They also don't have a high enough output for the TADD-1.
Agreed, that that regulator doesn't have sufficient margin for the entire
TADD-1.
I was suggesting using the low-noise high PSRR linear reg only to establish
the bias level.
There are indeed better parts. This one looks pretty good for an
integration solution (not include three C's):
http://datasheets.maxim-ic.com/en/ds/MAX6126.pdf
This app note, which filters the MAX6126 with an additional pass transistor
and opamp, shows how to get down to 6 nv/sqrt(hz):
http://www.maxim-ic.com/appnotes.cfm/appnote_number/3657
> < other circuit suggestions >
> This avoids blowing fuses if the supply polarity is reversed.
Or a PZT. We use a lot of them in the power circuit for hot plug sockets,
like on disk shelves. (A fuse is cheaper wrt to the BOM, but the warranty
costs kill you.)
> The problems of instability and coupling of power supply noise into the
> signal path were also present when single supply discrete transistor
> amplifier were the norm.
> Quite elaborate bias divider decoupling circuitry was used to minimise
> the effect.
Yeah, at some point a bipolar design becomes easier, right?
-ch
More information about the Time-nuts_lists.febo.com
mailing list