Ultra Precision Reference LTZ1000

[MiDi]

Glad I decided to order 4 LTZ1000 non-A from Farnell when they had the last available ones at €75 each, delivered.

Same, a year ago ordered my life time need. 

[CalibrationGuy]

Glad I decided to order 4 LTZ1000 non-A from Farnell when they had the last available ones at €75 each, delivered.

Same, a year ago ordered my life time need. 

OK, I have to ask. How many of them satisfied your lifetime need?

TomG.

[AnalogTodd]

The status of the LTZ1000 at the AD site is "PRODUCTION", only the distributors seem not sell these anymore. So I would not call that obsolescence here.

It may not be obsolescence in the exact meaning, but AD is making it such that only large companies can purchase these and they are not willing to entertain selling to smaller customers or through distributors. That precludes any start-up from being able to use them and create a new product to bring to market, not to mention preventing hobbyists from playing with the chip and coming up with new ideas.

LT supported startups and smaller companies (which kept them in those engineer's good graces as the companies grew, companies like Cisco) and sold small quantities to people via the Linear Express website. If you called in for support, you would get someone to help you. Jim Williams was a great example of being willing to talk to anybody. I know after Jim's passing, I took a phone call from a student who was trying to figure out the schematic of a SMU and I spent close to an hour helping him. We were taught that those students become the next great engineers and they remember when and where they got the help as they learned and grew.

[dietert1]

The way the US government handles international relations means people will look somewhere else, anyway. I'd guess sooner or later some Chinese chipmaker will come up with an equivalent. Maybe it already happened and we will learn about it sooner or later.

Regards, Dieter

[Dr. Frank]

The way the US government handles international relations means people will look somewhere else, anyway. I'd guess sooner or later some Chinese chipmaker will come up with an equivalent. Maybe it already happened and we will learn about it sooner or later.

Regards, Dieter

Hello Dieter and MiDi,
to my opinion, this will never happen.
The LTZ1000 has several very unique features, and is based on a >30 years old technology, which many other analog circuit manufacturers long time ago already have  abandoned.
The Chinese, or other countries will not have any commercial interest in re building such ancient analog fabs, or to copy the LTZ or ADR chip. I guess as well, that this attempt would not be technically successful with more modern fabs and technologies. (to be discussed)
The other, more important reason is, that the LTZ1000  is a niche product, i.e. there is no really important volume behind. There are only us few enthusiasts, and the demand of KEYSIGHT or KEITHLEY for the LTZ1000 and the demand of FLUKE for their LTFLU will for sure be safeguarded by longtermed binding contracts. I guess as well, that this is the only reason, why AD has not yet terminated this technology, i.e. not yet published a PTN.
This might be the real reason, why AD developped the ADR, i.e. only as a technology update, like the case of the 3458A, where a technology update was urgently necessary, due to the obsolescence of many of its components.
But as long the ADR1000 is not usable for DMMs due to its hysteresis effect, they will still not be able to replace the LTZ. They could do it, they only would have to use the same or similar die attach like the ones of the LTZ. And I could provide KEYSIGHT my working firmware change for acceptance of lower reference limits.

What might happen, that both the LTZ and the ADR in the future might be available for commercial customers only, like the LTFLU is available for FLUKE only, but no more for everyone, especially not for us 'amateurs'.

Frank

PS 26/01/30, 23h08
I just got the information from a volt-nuts friend, that AD sells minimum 100pcs only, from now on, i.e. for commercial customers only, no more for amateurs.
That's exactly the prediction I've made yesterday. So if no distributor offers that chip, due to extremely low demand, i.e. for us volt-nuts enthusiasts only, the access for us is closed. q.e.d.
I forgot to say, that big customers like KEYSIGHT , KEITHLEY, and alike, additionally with stringent need of quality / process control and traceability of all their components, usually / always buy directly at the manufacturer, rarely or never via distributors.

(I HAD 30 years of knowledge in a business with similar, even more stringent requirements  )

[Rax]

Interestingly, for some audio projects I am experiencing a resurrection of interest of sorts for, I've been looking for WIMA MKS2 10uF/50V capacitors - the only film caps that can feasibly replace electrolytics in most audio applications (including restorations), due to their incredibly small size - and they're nowhere to be found. A year ago - no problem. It seems that WIMA has now retired the model. This catered pretty specifically to the small crowd of audio afficionados. But it's likely there's much more going on at WIMA than just this.

It's almost like I'm looking for these niche parts from the US to Germany, and some of you guys look the other way, and we have essentially the same problem. Not that I like what's happening with the sourcing of parts here or anything - not to the slightest - but it seems to be a terribly widespread issue. It didn't really start now, but it's definitely spreading.

[Kleinstein]

AFAIR from a talk, the ADR1000 developement started before AD aquired LT.  So it was not developed as a replacement but more a competition or to complete the AD portfolio.

Beside the ADR1000, there is also the relatively new REF80 from Ti as a high end reference. The details of the real world performance (long term drift, hysteresis and similar quirks) are not yet public, but it could be an alternative.
The SMD ceramic case (similar to ADR1001) is however not ideal.
It would probably need one more iteration, but there could be alternative comming - though again from the US.

The supply issues and possible tarif uncertainties may be enough for some Chinese companies to look at least for an LM399 alterntive. It is not such a big step from ADR1399 performance to the LTZ1000.

[maat]

Interestingly, for some audio projects I am experiencing a resurrection of interest of sorts for, I've been looking for WIMA MKS2 10uF/50V capacitors - the only film caps that can feasibly replace electrolytics in most audio applications (including restorations), due to their incredibly small size - and they're nowhere to be found. A year ago - no problem. It seems that WIMA has now retired the model. This catered pretty specifically to the small crowd of audio afficionados. But it's likely there's much more going on at WIMA than just this.

It's almost like I'm looking for these niche parts from the US to Germany, and some of you guys look the other way, and we have essentially the same problem. Not that I like what's happening with the sourcing of parts here or anything - not to the slightest - but it seems to be a terribly widespread issue. It didn't really start now, but it's definitely spreading.

Well, this is another issue alltogether. WIMA was basically forced to discontinue many of their caps because their key suplier shut down on short notice. See attachment and https://www.luxtimes.lu/luxembourg/mylar-specialty-films-luxembourg-plant-to-shut-down-in-mid-2025-impacting-95-roles/34568003.html.

As far as I know from the last time I talked to them, they are looking for a replacement. The timeframe was late 2025. It seems they are running late...I might give them another call to find out if I have the time.

[MiDi]

to my opinion, this will never happen.

But as long the ADR1000 is not usable for DMMs due to its hysteresis effect, they will still not be able to replace the LTZ. They could do it, they only would have to use the same or similar die attach like the ones of the LTZ. And I could provide KEYSIGHT my working firmware change for acceptance of lower reference limits.

What might happen, that both the LTZ and the ADR in the future might be available for commercial customers only, like the LTFLU is available for FLUKE only, but no more for everyone, especially not for us 'amateurs'.

My comment was related to unavailability to end customers, fading out LTZ1000 w/o proper replacement available seems unlikely.
ADR1000 hysteresis due to off times is not that great, but lacking a proper comparison to LTZ1000, data for both appreciated.

Interestingly, for some audio projects I am experiencing a resurrection of interest of sorts for, I've been looking for WIMA MKS2 10uF/50V capacitors - the only film caps that can feasibly replace electrolytics in most audio applications (including restorations), due to their incredibly small size - and they're nowhere to be found. A year ago - no problem. It seems that WIMA has now retired the model. This catered pretty specifically to the small crowd of audio afficionados. But it's likely there's much more going on at WIMA than just this.

It's almost like I'm looking for these niche parts from the US to Germany, and some of you guys look the other way, and we have essentially the same problem. Not that I like what's happening with the sourcing of parts here or anything - not to the slightest - but it seems to be a terribly widespread issue. It didn't really start now, but it's definitely spreading.

Well, this is another issue alltogether. WIMA was basically forced to discontinue many of their caps because their key suplier shut down on short notice. See attachment and https://www.luxtimes.lu/luxembourg/mylar-specialty-films-luxembourg-plant-to-shut-down-in-mid-2025-impacting-95-roles/34568003.html.

As far as I know from the last time I talked to them, they are looking for a replacement. The timeframe was late 2025. It seems they are running late...I might give them another call to find out if I have the time.

Thanks for giving the background, luckily I got some stock before obsolescence.

[dietert1]

Some web finds concerning the WIMA caps:

WILTON, UK – 12 February 2024: Mylar Specialty Films, a leader in the production of differentiated polyester films, today .. The company ownership remains unchanged being a joint venture between Celanese and Teijin, and the company will continue to market the Melinex® PET, Hongji® PET, and Kaladex® PEN range of products in addition to Mylar® PET branded films.

Teijin to sell only Celanese acetate - Home Textiles Today
www.hometextilestoday.com › industry-news › teiji...
Under the new plan, Teijin will sell acetate filament products produced by Celanese in North America in the Asian market under the Celanese name. As a related ...

"The top global holding company for the Celanese Group of companies is Celanese Corporation, a Delaware company headquartered in Dallas, Texas"

Regards, Dieter

[Calandor]

Hi all,

being a silent guest for some while now, I had plans to join this nice forum for a longer period of time.
This was mainly because I am not sure if I can contribute anything to the community, being very interested in many things, but also neither very proficient nor as active as I might wish...

Now, with the offer from maat to make a pooled purchase (which I also considered as a last resort) I had no more excuses to delay joining in any further.
I just wanted to PM him, but found out you are not allowed to send PMs without having at least one post (which makes sense spammer-wise).
Well, I imagined my first post being different, but it is as is.

So, maat, please count me in with 3 LTZ1000.
PM follows, I hope that works now.

Now I probably should write an introduction in the new member thread...

[maat]

Oh what joy. DHL deliverd the order.

[rplabs]

Hi Maat,

I missed your message about the order, do you still have any LTZ reference available to sell?

Thanks!

[Andreas]

Hello,

Hmm Datecode 2308 for the "current" devices
so obviously with the "old" die attach.

https://www.analog.com/media/en/PCN/ADI_PCN_23_0011_Rev_A_Form.pdf

Did anyone get a device past 31-Jul-2023 (with the new die attach)?

with best regards

Andreas

[Dr. Frank]

never heard before about a new die attach.. is there a description about this change, i.e. a PCN available?
Hopefully, the new die attach won't lead to the same bad retracing behavior, like the ADR1000
Frank

[Andreas]

Hello Frank,

you find the link to the PCN directly within my last post.

And yes, I find it strange that 3 years after the PCN they still sell the old stuff.

with best regards

Andreas

[Dr. Frank]

It's the glass spheres only, same glue. I guess, this will NOT lead to any problems.
Hopefully ADI  will publish another PCN for the ADR1000,  i.e. change to the same die attach as for the LTZ1000A

[Kleinstein]

For the hysteresis from stress from the die-atach it is no only about the glue. There can also the factor on how sensitive the chip is to stress. It may take more than the same die atach to fix the ADR1000 hysteresis issues.

Just the manufacturer for the glass bubbles should not change that much for the LTZ1000, though there could still be effects on the long term.

[meandeev]

And today I got 2 of them! Thanks maat for the group-buy!   

Oh what joy. DHL deliverd the order.

[Andreas]

And today I got 2 of them! Thanks maat for the group-buy!   

Here the same.
Thanks Maat!

[rplabs]

What might happen, that both the LTZ and the ADR in the future might be available for commercial customers only, like the LTFLU is available for FLUKE only, but no more for everyone, especially not for us 'amateurs'.

Frank

PS 26/01/30, 23h08
I just got the information from a volt-nuts friend, that AD sells minimum 100pcs only, from now on, i.e. for commercial customers only, no more for amateurs.
That's exactly the prediction I've made yesterday. So if no distributor offers that chip, due to extremely low demand, i.e. for us volt-nuts enthusiasts only, the access for us is closed. q.e.d.
I forgot to say, that big customers like KEYSIGHT , KEITHLEY, and alike, additionally with stringent need of quality / process control and traceability of all their components, usually / always buy directly at the manufacturer, rarely or never via distributors.

(I HAD 30 years of knowledge in a business with similar, even more stringent requirements  )

Hi Frank,

I can confirm that ADI only sells to commercial customers even indirectly. I made an order recently via Mouser for some OPAMPs, nothing fancy just some OP97, everything looked fine, I paid for the whole order and the next day I received an email from Mouser that two rows in my order were cancelled. When I looked those were the ADI parts. I called Mouser to get more details and I was told that since October 2025, ADI doesn't sell components to private users that's why they had to cancel those parts.

[Dr. Frank]

What might happen, that both the LTZ and the ADR in the future might be available for commercial customers only, like the LTFLU is available for FLUKE only, but no more for everyone, especially not for us 'amateurs'.

Frank

PS 26/01/30, 23h08
I just got the information from a volt-nuts friend, that AD sells minimum 100pcs only, from now on, i.e. for commercial customers only, no more for amateurs.
That's exactly the prediction I've made yesterday. So if no distributor offers that chip, due to extremely low demand, i.e. for us volt-nuts enthusiasts only, the access for us is closed. q.e.d.
I forgot to say, that big customers like KEYSIGHT , KEITHLEY, and alike, additionally with stringent need of quality / process control and traceability of all their components, usually / always buy directly at the manufacturer, rarely or never via distributors.

(I HAD 30 years of knowledge in a business with similar, even more stringent requirements  )

Hi Frank,

I can confirm that ADI only sells to commercial customers even indirectly. I made an order recently via Mouser for some OPAMPs, nothing fancy just some OP97, everything looked fine, I paid for the whole order and the next day I received an email from Mouser that two rows in my order were cancelled. When I looked those were the ADI parts. I called Mouser to get more details and I was told that since October 2025, ADI doesn't sell components to private users that's why they had to cancel those parts.

Thats a new quality, as Mouser is a distributor, not ADI.
are you sure about the reason?
Any distributor should sell freely.
Frank

[picburner]

The exact same thing happened to me last year with an order from Mouser for ADI components (ADR1001AEZ & DG444DY+).
The order was canceled for the same reason.
The same material was later supplied to me by Digikey without any problems.

[bnz]

I had the same experience with Mouser. But they shipped the rest for free although the total sum dropped without the ADI parts under the 50€ minimum for free shipping.
So if they keep it like that thats at least a great way how to get free shipping from Mouser 

[rplabs]

Thats a new quality, as Mouser is a distributor, not ADI.
are you sure about the reason?
Any distributor should sell freely.
Frank

This is what I was told on the phone by a Mouser representative. Even if they are a distributor I think they have some contract with ADI and should abide by the rules of the manufacturer.