Old fashioned zener 10V reference

[Mickle T.]

Simple low noise voltage reference with 4 zeners. TC ~1 ppm/°C, 0.009 uV/V RMS noise (0.1-10 Hz).

Update 1: Fixed a stupid error in the circuit diagram

[EC8010]

I'm guessing that 3C108C is akin to 1N829? An Internet search didn't find them.

[Mickle T.]

This is a typical example of temperature-compensated zener diodes. It is difficult for search engines to find, since the letter “C” is written in Cyrillic.
https://www.optron.ru/catalog/stabilitronyi/2s108s/

[mawyatt]

Watch out as VD1 (12V) is across the 15V power input!!!

Best,

[Vtile]

Nifty design.

[Andreas]

0.009 uV/V RMS noise (0.1-10 Hz).

Hello,

you obviously measure the 6.5V output with relative high impedance ~130 Ohms.
So how is the input impedance of your LNA measurement amplifier?
And did you correct for the "voltage divider"?

with best regards

Andreas

[Mickle T.]

You are absolutely right. The internal resistance of the source is 134 Ohms. At the same time, the minimum input impedance of the amplifier is limited by a differentiating chain resistor of 3.3 kOhm. Therefore, noise amplitude correction was introduced.

[iMo]

In my $5 noise indicator project I reported aprox 2uVpp in 0.1-10Hz measured on a junkbox diy 6.9V zener @3.6mA.
2uV/2/6.6/6.9=0.022uV/V RMS in my case of 4 in parallel. His is 2x lower with special diodes @ 2x higher current, better construction and better LNA, so it fits well..
PS: here..

[Victorman222]

I wanted to measure some diodes for zero TC current and needed to make a reference to do relative measurement. It didn't need to be anything fancy but at the same time i wanted to try to make a hermetic box for it. First try was with some steel that solders nicely, but it didn't turn out hermetic (maybe instead could repurpose something like hermetic paper capacitor case). Then i remembered that i have some hybrid IC cases, quickly drew the most basic schematic, designed and etched PCB. The performance will probably be somewhere between good and bad...

[iMo]

After you test your prototype - for the final version I would cleanup the pcb carefully, also - when you are keen on filing the resistors - try to setup the divider from a larger value and a small value, and then do file the small value only..