Well sure, the LM329DZ is an excellent part ... but it's not a series of parts, it's only the 6.3V version.
Zeners are tricky around those voltages, must use temp compensated ones, I have used 1n3157 and 1n4784 for these voltages. The 1n3157 is excellent part. The 1n4738 is a regular zener.
1n829 performs better than lm329 and cheaper too.
1n829 performs better than lm329 and cheaper too.
homemodder said:
1 x 1n829 at newark = $9.09 - only source I can find in US
1 x lm329 at newark = $0.76 - cheapest price I could find in US
for now I think lm329 is good enough !
homemodder said:
Saw the datasheets, nice Zeners. Thanks.
Here we go then. Not just any Zener, but 1N40XX Microsemi temperature compensated components, are to be preferred by shunt builders if they can get their hands on them. Noise concerns by possible wrong Zener choices addressed.🙂
I use zeners in amps, in current sources, not ideal but it helps when I dont want turn on thump, also have a friend who works for a company that designs some very sensitive measuring instruments for ESA, European space agency, these guys use top notch components and he gives me hints here and there.
Thanks homemodder. 
Hi,
ESA hardly bothers about the sonic properties of components. There´s no reason to pay $9.09 for a noise generator.
ESA hardly bothers about the sonic properties of components. There´s no reason to pay $9.09 for a noise generator.
I'll try to get a few 1n406x zeners and compare their noise with 1n47xx zeners, just for fun, unless somebody's done it already. Thanks for the tip.
Edit: never mind, I can't find these at digikey, mouser, newark, jameco, at any price.
Edit: never mind, I can't find these at digikey, mouser, newark, jameco, at any price.
Lumba Ogir said:
A string of 4.7V normal Zeners then depending on Vout target, plus the odd LED for voltage trim?
Lumba If you read a bit further up the thread youll see my comment that at this voltage zeners are noisy as hell, who is taking of sonic qualities, have a closer look and youll see dynamic impedance has a effect on the noise of the part. The 1n829 is most probably the lowest noise 6.2 volt zener around.
Sorry, for a commercial vendor I cannot help, I get some when needed from you know who, also microsemi might give you some samples if you ask nicely. 🙂
Sorry, for a commercial vendor I cannot help, I get some when needed from you know who, also microsemi might give you some samples if you ask nicely. 🙂
A little food for thought, unrelated to zeners and leds. There's a little trick employed in driving bipolars at higher frequencies, using a small valued cap, 50p to 200p, across the base resistor. I was curious if it would have any effect and simulated the transition response with and without. One of the best simulated responses I got were with 2N3904 as Q2, and 33R || 50pF on its base. It seems to smooth the Vout response to abrupt transitions in the load current, without any obvious downsides. I realize we're talking here about very minor benefits.
Salas,
TL431. It has 0.2 Ohm dynamic impedance up to 100KHz, low noise and a nice turn-on characteristic.
I guess we just need a couple of cool PCB designs for +/- with 9240 - 240, Jfet or R option on the left, a few more pads for strings of lower noise 4V7 Zeners or LEDs, or TL431, so anybody can configure to his fancy. Also 9540s can be used for under 10V about 100mA applications like DAC PSUs. There faster counts.
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