Best out-of-the-box 10V reference?

[pitagoras]

Hi,
I would like to build my first "Mini Metrology Lab" (Conrad Hoffman).
Which would be the preferred way today for building a reference that can provide 10V without calibration?
I mean, I don't have easy access to a precision DMM... so it would need to have a reasonable 10V without adjustment.
Thanks

[Galaxyrise]

budget?

[Andreas]

Hello,

from datasheet
VRE310 (1 mV)

others: (2.5 - 5 mV)
REF102C
AD587U
LT1236A

I would take a AD587UQ

with best regards

Andreas

[Conrad Hoffman]

LT1236 might be interesting, 0.05% and 5ppm tc. Not very expensive. I'd be careful to float it on 3 points to avoid mechanical stress of the package. The 587 is also very good, but costs a bit more.

[pitagoras]

budget?

I don't think I can set any specific budget beforehand. Let's say $50?
The idea is to have a reference to calibrate many other things by, given that I don't have access to precision instruments.

[pelule]

How about AD588B reference, 10V +/- 3mV (+/-0.03% or +/-30ppm)?
Specs: http://www.analog.com/media/en/technical-documentation/data-sheets/AD588.pdf

I bought just for fun two of the cheap offered boards from China (15 EUR).
Link: http://www.ebay.de/itm/AD588-High-Precision-Voltage-Reference-Module-Multiple-Output-AD588BQ-/252181862385?hash=item3ab735d7f1
I had planned to use just the board, as I have 1x AD588BQ and 1x AD588JQ.

When the boards arrived, I tested them and found both well in spec.
Vref at 10V (+/-10ppm), Tempco less 0.8 ppm/°C and so far long term drift (yet) of less than 1ppm/1000hrs.

PeLuLe

[e61_phil]

How about AD588B reference, 10V +/- 3mV (+/-0.03% or +/-30ppm)?

3mV or 0.03% are 300ppm on 10V not 30ppm

Perhaps, anybody can measure such a reference and send it to the TO

[guenthert]

How about AD588B reference, 10V +/- 3mV (+/-0.03% or +/-30ppm)?
Specs: http://www.analog.com/media/en/technical-documentation/data-sheets/AD588.pdf

I bought just for fun two of the cheap offered boards from China (15 EUR).
Link: http://www.ebay.de/itm/AD588-High-Precision-Voltage-Reference-Module-Multiple-Output-AD588BQ-/252181862385?hash=item3ab735d7f1
I had planned to use just the board, as I have 1x AD588BQ and 1x AD588JQ.

When the boards arrived, I tested them and found both well in spec.
Vref at 10V (+/-10ppm), Tempco less 0.8 ppm/°C and so far long term drift (yet) of less than 1ppm/1000hrs.

PeLuLe

Uhm, 0.03% are 300ppm.  The AD588 is good, but not *that* good.  There are variations of the module listed above on Fleebay.  I like the "KKMOON" one, comes with a fairly nice case, 4mm banana plugs, convenient rechargeable (via USB plug) batteries and someone went through the trouble of measuring the output (with a HP34401a in unknown calibration state) and write the values down.  As far as I can tell works as advertised. 

[IconicPCB]

Hello Pitagoras,

It does look like a useful project and quite within range of possibilities. The 10V reference is a major issue.

In fact It does not need to be so much of a problem if a well known reference of any voltage is available. The ten volt source could be referenced and checked against any other well known source and characterized.
Later the ten volt source could be used as initially postulated in the article . But in reality 10V is an arbitrary choice where any other voltage would do.

A chatter named TiN ( working on HP 8.5 digit HPDVM has been able to offer in the past LTZ1000A based source. Unfortunately he has run out of printed circuit boards and apparently is not in a position to offer the reference any more. May be if we were to aggregate a number of people and purchase the PCB ( 4 layer affair ) , TiN might be persuaded to build more references. 

[TiN]

There is public open PCB of my design order available on OSH Park. Note they are not 10V, but 7.XXXXXX V sources, without any robustness (no protection against overvoltages/shorts/power polarity errors, etc).
However PCBs are lesser problem, compared to resistors (and their cost) required. So far I used only VPG resistors (with few internal test only exceptions) on my boards, and those set back from 120 to 350$ a set to build one PCBA. So it's rather expensive feat, and does not quite fit "Mini Metrology Lab" budgets/requirements.

Also LTZ module can't be used to check DMMs without calibration, which is whole another story (which takes fair bit of time and require at least a month of aging before calibration can be done). 

[pitagoras]

A chatter named TiN ( working on HP 8.5 digit HPDVM has been able to offer in the past LTZ1000A based source.

Yes I've followed somewhat his thread. Correct me if I'm wrong but LTZ1000 is the most stable source, BUT it does not provide a KNOWN voltage out of the box. So we would need a calibrated LTZ1000 source? Would he do that? Aged + calibrated LTZ1000-based reference?

[IconicPCB]

My  misunderstanding. Apologies.

[Conrad Hoffman]

You can also build the MML voltage source just as originally designed, but use the plastic package, the only one available now. It will be quite accurate if you match the gain resistors on the opamp. I don't think there are many references trimmed for initial accuracy that are going to be substantially better. AD588 can be 0.05%, but IMO, they're way too expensive.

[David Hess]

I like the idea of buying a bunch of references and building something but you can get an already calibrated 0.01% voltage reference for $30 from VoltageStandard.com.

[pelule]

    **
How about AD588B reference, 10V +/- 3mV (+/-0.03% or +/-300ppm)?

Sorry, was a typing error...

Conrad Hoffman
I don't think there are many references trimmed for initial accuracy that are going to be substantially better. AD588 can be 0.05%, but IMO, they're way too expensive.

Thats, why I tried that cheap Chineese (crap) offer at 15 EUR.

When the boards arrived, I tested them and found both well in spec.
Vref at 10V (+/-10ppm), Tempco less 0.8 ppm/°C and so far long term drift (yet) of less than 1ppm/1000hrs.

Thats my measurment results so far, still ongoing...
Just my idea for a cheap "out-of-the-box 10V reference" - compared to the cost of the LTZ1000 based references.

[Conrad Hoffman]

Unless you have a better meter than 5.5 or even 6.5 digit, there's little need for an LTZ1000 based circuit. FWIW, the original MML boards, once aged, only moved a couple ppm per year, sometimes even less. I checked one after a decade that was still that good, so those buried zener reference chips may be better than you think. Whatever you build or buy, it should be possible to find somebody to measure it, maybe some local company that has a common 6.5 digit Keysight meter or similar.

[SvanGool]

@Conrad Hoffman

You can also build the MML voltage source

Forgive me  my ignorance, can you explain what an MML voltage source/board is?
EEVblog search doesn't process three letter acronyms 

[The Soulman]

@Conrad Hoffman

You can also build the MML voltage source

Forgive me  my ignorance, can you explain what an MML voltage source/board is?
EEVblog search doesn't process three letter acronyms 

Mini Metrology Lab

http://conradhoffman.com/mini_metro_lab.html

[SvanGool]

Sorry, should have known that, temporary black-out 

[Conrad Hoffman]

Sorry, that's the problem with TLAs!

[The Soulman]

Sorry, that's the problem with TLAs!

Ok, what's a TLA? 

On a different note, is it correct that (buried) zener references have better long term stability than bandgap references?

[bingo600]

Sorry, that's the problem with TLAs!

Ok, what's a TLA? 

On a different note, is it correct that (buried) zener references have better long term stability than bandgap references?

Three Letter Acronyms ??

IBM had a thick book , just explaining their version of them

/Bingo

[The Soulman]

Sorry, that's the problem with TLAs!

Ok, what's a TLA? 

On a different note, is it correct that (buried) zener references have better long term stability than bandgap references?

Three Letter Acronyms ??

IBM had a thick book , just explaining their version of them

/Bingo

Thanks... 

[Andreas]

On a different note, is it correct that (buried) zener references have better long term stability than bandgap references?

Hello,

in principle: yes (if you compare the same package and the bare reference element).
In practice: there is also a influence of the scaling resistors which are used to get from the 6-7V or 1.22V to the final output voltage.
The best packages are hermetically sealed ones like metal can or CERDIP.
From the plastic packages DIP8 packages behave usually better than smaller (SMD) packages.

so for best performance you should use a 6-7V temperature compensated buried zener in a hermetically sealed metal can package.

With best regards

Andreas

[retrolefty]

A non-volt-nut here with a question.

 Why must there be a 10vdc output standard with all the added complexity and variation of the opamp stage. Why not just output the zener's natural reference voltage? Just measure and record it's voltage upon manufacture of the standard for future tracking with proper calibration standards.

One just ends up with a voltage number either way suitable for measurement, trending with time, etc, and should be usable via mapping calculations for any user's need? Is there not value in eliminating sources of variation altogether. OK maybe a buffer X1 opamp might still be desirable?