Best low noise regulator?

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with Cset=22u
 

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All the measurements were done at the same time with the SSM2019 balanced preamplifier at a gain of 100. The AP has a filter factor of √0.2316 * F in the analog mode. So I wrote an AP basic macro to plot Volts/√Hz.

As a sanity test, I ran the tests and compared numbers to those in his 1995 articles. They seem to compare closely, although he was able to measure impedance lower than I witnessed.
 
All the measurements were done at the same time with the SSM2019 balanced preamplifier at a gain of 100.

Good. It is nearly meaningless to compare results copied together from
unspecified sources. That's why I did the series on lab supplies, references,
regulators and batteries.

The GR-noise-like appearance of the noise in the Sulzer does not need
to come from the measurement system, it can be just as well in the regulator
itself. From the circuit I just found on the tangentsoft site
< Op-Amp Based Linear Regulators >
I would guess that we just see the noise voltage of the 47K-resistor to the ninv-input
of the op amp that is not good enough filtered for really low frequencies by
the 1uF tantalum. That is easily and cheaply cured.

The -3dB frequency may be 3 Hz, but at -3 dB Xc is just == R, so there
is not much shorting of the resistor's noise voltage.

I must confess that I did the same mistake in the input coupling of my preamp
and Scott spotted it immediately.

Reading the website article, I find it kinda funny how names are attached to
textbook circuits and they are carefully updated, as if soldering a LM317 in front
of another regulator was the culmination of patent-worthy IP that required
a new name. That does not apply to the Jung reg.

regards, Gerhard.
 
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Use an LT3042 and an outboard PNP or NPN transistor. The LT1086-5 isn't even remotely in the same ballpark.

I have made a tiny layout for the npn circuit in the data sheet.
I have no idea of a negative version that does not have at least
2 op amps.
It will take some time until I can test that. A lot of stuff in the pipeline
in front of it.

regards, Gerhard
 

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