[time-nuts] Super Regulator links

[John Miles]

> Congratulations, you've been seduced by the quoted noise without
> considering what it actually means.
> This is just the sort of reaction the marketers hope to induce.
> This is a natural reaction, you should be more skeptical of first
> impressions.

Exactly.   It appears that the XC6204 is only quieter than an unbypassed
LT1762.   The lack of any way to bypass its internal reference costs it the
ball game.  Compare the graphs on page 36 of its data sheet with those on
page 8 of the LT1762's.

It's hard to find a regulator that DOESN'T say "Low noise" somewhere in its
spec sheet.  It's like shopping for VCOs, where you get the obligatory "Low
phase noise" bullet point on 1-2 GHz parts rated for -80 dBc/Hz at 10 kHz.

By the way, to answer the earlier question, the main reason you need
extremely low-noise regulators is to achieve rated VCO noise specs.  The
supply sensitivity of an HMC506LP4, just to throw out an example, is 78
MHz/volt at VTune=5V.  Most off-the-shelf VCOs aren't that sensitive at
their tuning ports!

-- john, KE5FX