Lowest noise Zener Diodes?

[Joshua_G]

Which are the lowest noise Zener Diodes, either SMD or through hole, which are in current production, regardless of price?

[homemodder]

Temp compensated ones like lm329. There are better ones but although you say regardless of price I doubt you want to fork out 60 to 70 dollars for a single part, these are used in space exploration equipment and satelites. Read linear technology application AN82F, very good info on there. You could also make yourself one, just combine a regular zener with a diode.

[MarcelvdG]

I don't know, but I do know that you should use a voltage well below 5 V if you want low noise, like 3.9 V or less. Higher voltage "zeners" actually have avalanche rather than Zener breakthrough, which causes much more noise.

[Joshua_G]

Originally Posted by homemodder

Temp compensated ones like lm329. There are better ones but although you say regardless of price I doubt you want to fork out 60 to 70 dollars for a single part, these are used in space exploration equipment and satelites. Read linear technology application AN82F, very good info on there. You could also make yourself one, just combine a regular zener with a diode.

Thanks.
Indeed, $60-70 a piece I cannot afford (since I need quite a few of those).
How do I combine a regular diode with a Zener to lower its' noise?

[Wavebourn]

Theoretically the lowest noise Zeners are for about 8.2V

Also, here is some list I fond in the Net:

CMHZ4099: 6.8 V, Low Noise Zener Diode
CMHZ4100: 7.5 V, Low Noise Zener Diode
CMHZ4101: 8.2 V, Low Noise Zener Diode
CMHZ4102: 8.7 V, Low Noise Zener Diode
CMHZ4103: 9.1 V, Low Noise Zener Diode
CMHZ4104: 10 V, Low Noise Zener Diode
CMHZ4105: 11 V, Low Noise Zener Diode
CMHZ4106: 12 V, Low Noise Zener Diode
CMHZ4107: 13 V, Low Noise Zener Diode
CMHZ4108: 14 V, Low Noise Zener Diode
CMHZ4109: 15 V, Low Noise Zener Diode
CMHZ4110: 16 V, Low Noise Zener Diode
CMHZ4111: 17 V, Low Noise Zener Diode
CMHZ4112: 18 V, Low Noise Zener Diode
CMHZ4113: 19 V, Low Noise Zener Diode
CMHZ4114: 20 V, Low Noise Zener Diode
CMHZ4115: 22 V, Low Noise Zener Diode
CMHZ4116: 24 V, Low Noise Zener Diode
CMHZ4117: 25 V, Low Noise Zener Diode
CMHZ4118: 27 V, Low Noise Zener Diode
CMHZ4119: 28 V, Low Noise Zener Diode
CMHZ4120: 30 V, Low Noise Zener Diode
CMHZ4121: 33 V, Low Noise Zener Diode
CMHZ4122: 36 V, Low Noise Zener Diode
CMHZ4123: 39 V, Low Noise Zener Diode
CMHZ4124: 43 V, Low Noise Zener Diode
CMHZ4125: 47 V, Low Noise Zener Diode
CMHZ4614: 1.8 V, Low Noise Zener Diode
CMHZ4615: 2 V, Low Noise Zener Diode
CMHZ4616: 2.2 V, Low Noise Zener Diode
CMHZ4617: 2.4 V, Low Noise Zener Diode
CMHZ4618: 2.7 V, Low Noise Zener Diode
CMHZ4619: 3 V, Low Noise Zener Diode
CMHZ4620: 3.3 V, Low Noise Zener Diode
CMHZ4621: 3.6 V, Low Noise Zener Diode
CMHZ4622: 3.9 V, Low Noise Zener Diode
CMHZ4623: 4.3 V, Low Noise Zener Diode
CMHZ4624: 4.7 V, Low Noise Zener Diode
CMHZ4625: 5.1 V, Low Noise Zener Diode
CMHZ4626: 5.6 V, Low Noise Zener Diode
CMHZ4627: 6.2 V, Low Noise Zener Diode

And here are Soviet diode-compensated Zeners for 9V, $3/dozen:

D818G USSR Zener Diodes Lot of 12 | eBay

[SY]

Originally Posted by Joshua_G

How do I combine a regular diode with a Zener to lower its' noise?

You can't.

Best Zeners are 6.2V, which sits on the cusp of Zener and avalanche. Forward biased red LEDs are even quieter.

[Joshua_G]

Thanks, all.

[sreten]

Hi,

Parallelling cheaper devices is the obvious answer if noise is really an issue.

Theoretically 2 devices drop noise by 3dB, 4 by 6dB, 8 by 9dB etc, but
practically its never that simple and the point of no real benefit reached
for extra devices are 2 devices to about 6 devices usually.

(Might be a bigger number with devices not designed for low noise, but
that is pointless, you want cheap low noise devices in the first place.)

rgds, sreten.

[rsavas]

Would a TL431 be lower noise than a zener. I have read that the ones from ONSEMI are the lowest noise of the various mfgs.

[AndrewT]

I thought 431 were a lot noisier.