Author Topic: LM399 based 10 V reference (Read 545740 times)

Andreas · « **Reply #425 on:** February 24, 2016, 09:32:31 pm »

Hello,

thank you for the data.
But my hopes that the LM399AH will be better are destroyed.
The output voltage and then the T.C. are both too high.
Attached: updated chart with LM399AH

With best regards

Andreas

branadic · « **Reply #426 on:** February 24, 2016, 09:53:36 pm »

Thanks for the update Andreas. Seems like I need to measure my mixture of LMMx99 too (also some National Semiconductor LMx99), to give it a further statistics.
Maybe you want to share the complete data table?

TiN · « **Reply #427 on:** February 25, 2016, 08:06:37 pm »

Better in Excel format

You guys get me interested too.

Some tests without heater:

Perhaps better to bodge up test jig with SMU to ramp zener current from 100uA to 10mA in 100uA steps and with Heater on/off switch?

fluxamp · « **Reply #428 on:** February 28, 2016, 04:43:20 pm »

Thought I'd share my build of the simple LM399 based transfer. It uses the self-biasing circuit posted in the first few posts.
I used a double-walled soup container/flask from Ikea as a housing and SMA connectors for unbuffered 7V zener voltage and 10V main output.

The pink stuff is packaging material from Farnell that I used to isolate the board from the metal walls. At the top of the board sits an LM317 and underneath the white foam is the LM399. The gain setting resistors are all located below.

The blue coated resistors are Vishay PTF56 (5ppm/K) that are mounted on little standoffs. That way I didn't have to bend the legs. Unfortunately, I had a bit of brain-freeze when ordering them, so I needed to parallel them up to get the right values

The back of the board only holds the LTC2057 and some more foam.

Currently the unit sits in a lab corner powered 24/7 to observe the thermal behavior. Its intended purpose is momentary measurements so it's not going to be powered for any extended time. But I thought it'd be interesting to see whether the LM317 generates enough heat to upset the LM399 or influence the gain setting resistors. After half a week I opened the lid and the inside was a few K warmer than the outside of the case but not by a lot. For the next build I'll try some different things.

TiN · « **Reply #429 on:** February 28, 2016, 04:52:51 pm »

Clean build! Is that wire triax from ebay? I was just making pair of cables using very similar looking low-noise triaxial.

fluxamp · « **Reply #430 on:** February 28, 2016, 05:00:01 pm »

Thanks! The white wire is "only" coax. My boss gave it to me so I have no clue where it comes from, sorry.

Andreas · « **Reply #431 on:** February 28, 2016, 10:25:57 pm »

Quote from: TiN on February 25, 2016, 08:06:37 pm

Perhaps better to bodge up test jig with SMU to ramp zener current from 100uA to 10mA in 100uA steps and with Heater on/off switch?

Hello,

what do you want to do with that?
below 0.5mA the behaviour is undefined (according to datasheet).
above that you should measure the differential resistance of the zener (around 0.5 Ohms).
I bet that the 1826-1249 has near 6.9 V (+/- 0.04) output at 1 mA with heater on.

Quote from: fluxamp on February 28, 2016, 04:43:20 pm

Thought I'd share my build of the simple LM399 based transfer.

Interesting housing.
First I thought that also the lid is some metal.
But obviously it is isolating plastic.

with best regards

Andreas

Galaxyrise · « **Reply #432 on:** February 28, 2016, 11:19:10 pm »

Quote from: Andreas on February 28, 2016, 10:25:57 pm

Quote from: TiN on February 25, 2016, 08:06:37 pm
Perhaps better to bodge up test jig with SMU to ramp zener current from 100uA to 10mA in 100uA steps and with Heater on/off switch?
what do you want to do with that?
below 0.5mA the behaviour is undefined (according to datasheet).
above that you should measure the differential resistance of the zener (around 0.5 Ohms).

Just a reminder that the reference section current is not the zener diode current. Current through the buried zener is always around 250uA in normal operating conditions. This is called out nicely in National Semi's App Note 161 (http://www.ti.com/lit/an/snoa589c/snoa589c.pdf)

Mickle T. · « **Reply #433 on:** May 07, 2016, 10:09:41 am »

Another simple DMM tester (now with the stupid mistake on the label

).
Voltage output 0...10 V with 1 ppm resolution and 1 ppm INL. TempCo -0.2 ppm/K. Output resistance 0.002 Oh. LF noise (0.1-10 Hz): 10 V - 2.4...2.8 uV p-p, 0 V - 0.2...0.25 uV.
Current output 0...10 mA with 1 ppm resolution. TempCo -3 ppm/K
3wire-resistance: hermetic foil 1kOhm +3 ppm/K, 10 kOhm +/-1 ppm/K, hermetic PWW 100 kOhm -2,6 ppm/K, 1 MOhm <10 ppm/K.

necessaryevil · « **Reply #434 on:** May 29, 2016, 09:08:20 pm »

I'm impressed Mickle. But what mistake do you mean?

ebclr · « **Reply #435 on:** May 29, 2016, 09:20:23 pm »

https://www.taobao.com/view_image.php?spm=a312a.7728556.2015080703.1.7UZkf9&pic=HEYVDllCEghRV1dcWwocCUQOFx0XTEJfW1lXDBZFAlpcMAl9eXE7MRRUDzQuE1BhaERiZwNbQlpeXV0OSFM=&title=TE0zOTkgUENC&version=2&c=MWIzOTMwMTNhMzgzMDI0OWY4MzY3ZGNiNjE5OWM4NDA%3D&itemId=14154303091&shopId=58559233&sellerRate=25555&fv=9

Kleinstein · « **Reply #436 on:** May 29, 2016, 09:28:38 pm »

The mistake is just labeling: "DC Voltage 0-10.0... mA"

TheAmmoniacal · « **Reply #437 on:** May 30, 2016, 06:24:06 am »

Quote from: ebclr on May 29, 2016, 09:20:23 pm

https://www.taobao.com/view_image.php?spm=a312a.7728556.2015080703.1.7UZkf9&pic=HEYVDllCEghRV1dcWwocCUQOFx0XTEJfW1lXDBZFAlpcMAl9eXE7MRRUDzQuE1BhaERiZwNbQlpeXV0OSFM=&title=TE0zOTkgUENC&version=2&c=MWIzOTMwMTNhMzgzMDI0OWY4MzY3ZGNiNjE5OWM4NDA%3D&itemId=14154303091&shopId=58559233&sellerRate=25555&fv=9

What is this PCB?

Macbeth · « **Reply #438 on:** May 30, 2016, 07:07:29 am »

Quote from: TheAmmoniacal on May 30, 2016, 06:24:06 am

Quote from: ebclr on May 29, 2016, 09:20:23 pm
...bad link...

What is this PCB?

Link doesn't work for me. A better one https://world.taobao.com/item/14154303091.htm

Looks like a way of using up lots of reclaimed S102 10K000's. Perhaps there is a glut of them on the taobao market?

Dave · « **Reply #439 on:** May 30, 2016, 11:14:00 pm »

Very clean build, Mickle.

What did you use to machine the openings in the case and how did you put the text/symbols on it?

Mickle T. · « **Reply #440 on:** May 31, 2016, 05:52:08 am »

LCD opening was made by CNC milling machine. All others - by hand drill.

Dave · « **Reply #441 on:** May 31, 2016, 05:04:28 pm »

What about the writing and symbols on the front panel?

Mickle T. · « **Reply #442 on:** May 31, 2016, 05:15:00 pm »

Laser printer film and 3M adhesive

Sbampato12 · « **Reply #443 on:** May 31, 2016, 06:13:36 pm »

Quote from: Mickle T. on May 31, 2016, 05:52:08 am

LCD opening was made by CNC milling machine. All others - by hand drill.

Wich are these banan receptacles? (Manufactures, code, or where to buy?)
They look very good!

Mickle T. · « **Reply #444 on:** May 31, 2016, 06:57:27 pm »

Sorry, don't know code/mfr of these connectors

ebclr · « **Reply #445 on:** May 31, 2016, 07:15:35 pm »

Ve se este serve

https://world.taobao.com/item/522839915395.htm?spm=a312a.7700714.0.0.4vuSFA#detail

kridri · « **Reply #446 on:** June 08, 2016, 11:45:34 am »

For my coming voltage reference I was doing my research on ovens and I found a lot of references to two papers of Jim Williams. But when google it or look in the library (University library with connections to other universities) I can't find them. Does some one have them or knowing where I can find them?

It is specific about these papers:
- Temperature controlling to microdegree (MIT 1971)
- Portable wide range chopper stabilized temperature controller (MIT 1974)

blackdog · « **Reply #447 on:** June 09, 2016, 10:01:38 am »

Hi,

Kridri,
Is this wat your looking for?
www.bramcam.nl/Diversen/EDN-Split-a-temperature-degree-to-10uC.pdf

Kind regarts,
Bram

kridri · « **Reply #448 on:** June 09, 2016, 12:36:21 pm »

Quote from: blackdog on June 09, 2016, 10:01:38 am

Hi,

Kridri,
Is this wat your looking for?
www.bramcam.nl/Diversen/EDN-Split-a-temperature-degree-to-10uC.pdf

Kind regarts,
Bram

Hi Bram
Apparently Flinstone has deleted his message. He also posted the same article like you. I already read it and wanted to read the thesis/paper for which that article is written. But i can't find it online.

Greetings

Kris

kridri · « **Reply #449 on:** June 09, 2016, 03:04:47 pm »

Quote from: EmmanuelFaure on June 09, 2016, 02:25:05 pm

@ kridri : I have looked for these 2 articles too, I was never able to find them. Especially nothing on Worldcat, it means that unfortunatelly there's no copies of these papers publicy available.

In google scholar, if you type the title and include citations in the search results, you can discover that most of citing papers were written by Jim Williams himself. The others were written in the 70's so there no chance that you can get a copy by contacting the authors.

https://scholar.google.fr/scholar?cites=9898204615121267227&as_sdt=2005&sciodt=0,5&hl=fr

I thought about contacting the MIT library, but as there's nothing in their catalog about this paper, I doubt they could do anything. Maybe the best chance is to contact the Linear Technology staff? I'm quite sure Jim would have kept a copy of this paper in his library.

BTW, if you're looking for papers about sub-milidegree temperature control, plenty were published in the 70's in the scientific journals. BTW-bis, another companion-paper for the MIT oven : "McDerrnott, James. 'Test System at MIT Controls Temperature of Microdegrees." Electronic Design (January 6,1972)" (Not available online).

I also searched in google scholar and via my university library but no hits. About contacting MIT library, unfortunately you can only contact them as a student or alumi. Otherwise you must visit them. I will send LT a mail with the question and post the result here!
Thanks for thinking with me!

PS: Do you have some good references about sub-milidegree temperature control?


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Author Topic: LM399 based 10 V reference (Read 545740 times)

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