what happened to LTZ1000 stocks? - Page 1
Forum section: electronics / general

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 01:38:13 pm
content: is analog devices at "work" here ?regards.

author: Andreas
author_rank: Super Contributor
timestamp: November 14, 2017, 02:10:12 pm
content: Hello,most probably Keysight will offer his brand new 34480 in 6-12 monthswith best regardsAndreas

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 02:13:22 pm
content: Quote from: Andreas on November 14, 2017, 02:10:12 pmdoubt that very much.keysight has lost its mettle.best regards.

author: tszaboo
author_rank: Super Contributor
timestamp: November 14, 2017, 02:33:34 pm
content: Quote from: Andreas on November 14, 2017, 02:10:12 pmThose 10-100 LTZ1000s that are usually stocked at Digikey and Mouser can easily purchased by a single even small manufacturer, if they need them in a hurry.

author: TiN
author_rank: Super Contributor
timestamp: November 14, 2017, 04:08:31 pm
content: Quote from: NANDBlog on November 14, 2017, 02:33:34 pmIt's not available on DK either since August.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 14, 2017, 04:39:55 pm
content: Linear Tech is evaluating some new materials suppliers and testing them in their process for LTZ1000a, they tell me they will be able to ramp up production very soon. We just got notified our August order will be shipping in the next week or thereabouts.The LTZ is not going anywhere and will remain in the parts catalog, it will eventually become branded AD but right now it is still LT.

author: chuckb
author_rank: Frequent Contributor
timestamp: November 14, 2017, 04:45:32 pm
content: I'm seeing a 4-6 week leadtime through Digikey. Order the parts and they will be shipped when Digikey gets them. My credit card does not get charged until the parts ship. Don't wait till you need them to order them.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 04:50:42 pm
content: Quote from: MisterDiodes on November 14, 2017, 04:39:55 pm"new materials suppliers" and "ramp-up" leads me to ask:-1. why new materials on an already proven die?2. why was the production stopped / slowed-down?dangerously close to the time of AD takeover, what gives?regards.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 14, 2017, 05:08:43 pm
content: They might need relative special wafers to get the best performance. A new source might give lower cost or better performance or just an alternative in case the old source an not deliver. Also the TO99 case is kind of special now - not used that often anymore.Not sure this delay is related to the AD merger. Though it is possible the the merger did add a little to the delay as management was busy with other things.Such a special chip will not be produced every weak - more like a batch for the next months or year. It might also include quite some lead time for extended anneals / curing and a chance for a batch to turn out bad, thus an unexpected delay.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 05:13:12 pm
content: Quote from: Kleinstein on November 14, 2017, 05:08:43 pmLTZ1000P(CZ) 8 pin DIP/SOIC package?

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 14, 2017, 05:27:15 pm
content: Again: My LT apps engineer got the info from their Vref line production manager, and the design has NOT changed at all. They had to evaluate a new materials supplier (not wafers, that's all they said), do some detailed spec-sheet performance testing to make sure all is well, and then resume shipping. You can't test LTZ's overnight. This apparently has nothing to do with merger; I wouldn't read too much into it. This happens in the low ppm world.We have seen delays like this before now and then - these are not exactly easy to make and test, and remember you've got the big customers ahead of you in line.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 05:48:43 pm
content: Quote from: MisterDiodes on November 14, 2017, 05:27:15 pmlow ppm = low profits per month.what would be LTZ1000 contribution to the bottom line? 1-2 million per year?regards.

author: GreggD
author_rank: Regular Contributor
timestamp: November 14, 2017, 05:57:48 pm
content: In TO-5, Arrow has 14, Chip1stop has 17

author: Andreas
author_rank: Super Contributor
timestamp: November 14, 2017, 06:40:29 pm
content: Quote from: MisterDiodes on November 14, 2017, 04:39:55 pmHello,I hope that they will not change the die attach.Otherwise I fear the stability will not be the same as before.(Similar to the LT1027 which has suffered from the LS8 package/die attach in my opinion).with best regardsAndreas

author: floobydust
author_rank: Super Contributor
timestamp: November 14, 2017, 08:06:09 pm
content: If it's not the wafer, what "new materials supplier" is there? Who's putting the gun to their head to change suppliers on this sole-sourced part.Logically, continue making it with the old material until the new material gets approved.Any quality/supply issues will cause big trouble for manufacturers dependent on it.I'm skeptical. Mergers and acquisitions are never good for products.AD will surely consolidate fab, remove redundant teams, "improve" things to lower costs. Increasing shareholder value is paramount and great art is never about that.

author: branadic
author_rank: Super Contributor
timestamp: November 14, 2017, 08:24:59 pm
content: Maybe Analog Devices needs the LTZ for their own reference modules on AD5791. See the articleHigh Precision Voltage Sourcefrom Oct. 2017.EVAL-AD5791SDZ expected availability @ RS Components on 21.02.2018-branadic-

author: Edwin G. Pettis
author_rank: Frequent Contributor
timestamp: November 14, 2017, 08:39:47 pm
content: Problems with material suppliers is nothing new, my guess is that LT's current material supplier is having problems with the purity and it is causing problems for the LTZ, this would not be a wafer level problem, given the higher performance level, impurities are critical. We've had problems with resistance alloy suppliers in the past, going back decades, which caused a lot of trouble. This happens and often finding a new supplier is the solution. Rest assured, there is no change to the LTZ as it is made, there is absolutely no move to put it in a different package, it wouldn't work to spec otherwise. I rather doubt it has anything to do with the die leads either, but exactly what is causing the problem is unknown outside of Linear Tech as such.Back in the old days, we had vertical manufacturing, a semi house did everything, raw materials came in one door and the finished product came out another door, everything done under one roof in effect. Nobody has that kind of integration now, it has gotten too expensive and too many regulations. And with that change, managing quality control of materials became much more difficult, many books and articles have been written about the supply chain and how it is spread around the world complicating quality control. It is no simple matter these days.This kind of disruption happens all the time in ICs, if you kept an eye on delivery dates, you can always tell when supply is not meeting demand for a myriad of reasons and raw materials are often at the head of the list. A lot of those raw materials comes from countries that are not the most stable on the planet. Those that process the raw materials are also scattered all over the globe, just try keeping control of all of the variables involved all the time. The fact is even highly reputable companies can run into problems and it can take a lot of time to fix it, customers can't wait very long in most instances.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 08:52:29 pm
content: Quote from: branadic on November 14, 2017, 08:24:59 pmnote the "x1000" mark, would that mean - AD1000? (relabelled)regards.

author: Echo88
author_rank: Frequent Contributor
timestamp: November 14, 2017, 09:04:06 pm
content: Do they have documentation on this X1000-board? Since the old standard AD5791-base-board has LTZ-1000-layout errors according to Mickle T.

author: EEVblog
author_rank: Unknown
timestamp: November 14, 2017, 10:46:49 pm
content: Quote from: zhtoor on November 14, 2017, 05:48:43 pmYou could say that about almost every one of the thousands of chips in their portfolio. Small profits across thousands of different productsistheir business.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 14, 2017, 11:01:06 pm
content: Quote from: EEVblog on November 14, 2017, 10:46:49 pmhello,lets look at a little bit of history:-1. REFAMP SZA263 by motorola used in 731's - production dropped - not feasible / profitable.2. LTFLU done by LT+Fluke used (internally) in 732's - production dropped (?) - not feasible / profitable.3. LM399/199 done by National Carried over by LT - production? (questionable production future?)4. LTZ1000 done by LT acquired by ADI - just compare volumes of a typical power product with a high-end vref like LTZ1000 - questionable profits.i for one don't want to sound alarmist, but there might be financial difficulties in sustaining the high-end production line.(i would definitely want LT/ADI to continue producing a stellar product like LTZ1000, even at a price hike - reasonable that is)second source anyone? microsemi? linearsystems? (or shanghai factory #17)or maybe availability of the bare die product?regards.

author: floobydust
author_rank: Super Contributor
timestamp: November 15, 2017, 02:14:54 am
content: LTZ1000A is USD $60 (USD $70 in Canada) from Digikey. Surely there's room for decent margin and possibly another manufacturer now. I doubt Fluke or Keysight etc. like being held by their balls on this.I'm not sure what the production time constant is - from start to finish.Synthetic quartz crystals take 2-6 months to grow(Epson), an example of a long time-constant. By the time you realize you have a problem, it's too late. The batch is in the garbage and hmmm what caused it.You must have a stable process, patient (management), tolerate low yields, have expensive test equipment, highly skilled people - a precision manufacturing environment with some art to it.That is harder and harder to accomplish and I find larger corporations fumble around, bungle it and then give up. Impatience, dumb leadership, and weak commitment all contribute.Smaller companies are agile, flexible and LT was pretty good for niche products of higher quality.So I think these parts are dropped due to the unique production requirements and oddball nature of them, compared to the big corp's "let's pound out the op-amps and make $" business plan.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 15, 2017, 03:40:03 am
content: Quote from: floobydust on November 15, 2017, 02:14:54 amKFLU-1K?on a more serious note, how about an open-source-chip project as in crowd-sourcing, maybe rope-in TSMC or some other fab?(Bob Dobkin could be of some help)regards.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 15, 2017, 04:00:22 am
content: or maybe a cheaper package supplier from china?(or LT/ADI have neophytes like me in the CAD section!)regards.

author: VintageNut
author_rank: Frequent Contributor
timestamp: November 15, 2017, 04:12:20 am
content: ADI uses TSMChttp://www.analog.com/en/about-adi/news-room/press-releases/2012/06_20_12_adi_and_tsmc_collaborate_on_new_analog.html

author: tszaboo
author_rank: Super Contributor
timestamp: November 15, 2017, 09:38:16 am
content: Quote from: floobydust on November 14, 2017, 08:06:09 pmCan be the steel in the metal can, can be the kovar for the leads, maybe it is the isolation standoff. None of which should effect the performance too much.Dont be afraid for the LTZ1000. I'm sure that Agilent and Linear signed a contract for the availability, which is a bounding contract for Keys. and Analog.Also, if they change something, they need time to verify it. This is not a digital gate, where you measure the rise time, and say that it is OK. Just making sure, that the drift for the first 2x1000 hours is OK: 3 months. With about 12 weeks extra as lead time.Linear has a very different approach for the market. They make products, which sells in the 1000s and not the millions, and they have higher profit margin on it. Why sell microcontollers with billions of transistors in it, and have 5 cents of profit on each, when you can sell an opamp with a dollar of profit on it. The LT5400, which is "just" 4 resistor sells for almost the same as a Apple A8.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 16, 2017, 12:11:58 am
content: Quote from: NANDBlog on November 15, 2017, 09:38:16 amshould be so.anyways, this blog can *maybe* change their mind if they plan to do any hanky-panky.viva la voltnutland!regards.

author: Muxr
author_rank: Super Contributor
timestamp: November 16, 2017, 04:46:41 am
content: I ordered a LTZ1000A 4 months ago directly from Linear's website.. still waiting.

author: montemcguire
author_rank: Regular Contributor
timestamp: November 16, 2017, 06:46:19 am
content: Arrow has 14 LTZ1000CH#PBF right now. It's not the 'A' version, but it is an LTZ1000

author: bopcph
author_rank: Contributor
timestamp: November 16, 2017, 06:25:28 pm
content: I am pretty sure (99%) the LTZ1000 won't go into obsolescence in near future.Ever heard of the mil./space version of LTZ1000 with a price tag of US$1500 -might be DKK 1500 =US$ 300, pardon but I remember the number 1500 and not the sales channel, the number had me running in search for another sourceWhat I do remember is the claim of "longe lead-time EOL sourcing", "One known fab only" (US as I remember), "narrowed wafer specs", "preconditioned" ...... and a documentation the size of the holy bookAny one ever thought of what it takes to produce and prove a product that stable that other people are willing to bet 10-11 digit US$ project on it ?If you "own" that product you won't "kill" it

author: gamalot
author_rank: Super Contributor
timestamp: November 16, 2017, 06:46:36 pm
content: Chip1stop has 17 LTZ1000CH#PBF in stock.

author: Muxr
author_rank: Super Contributor
timestamp: November 16, 2017, 07:34:12 pm
content: Quote from: Muxr on November 16, 2017, 04:46:41 amQuoting myself to provide an update. I contacted Linear.. they said they'd be shipping me one today. So I guess my order just got forgotten somehow. Or they felt bad and are giving me one from a secret stash.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 16, 2017, 07:41:18 pm
content: Quote from: Muxr on November 16, 2017, 07:34:12 pm

author: hwj-d
author_rank: Frequent Contributor
timestamp: November 16, 2017, 10:58:59 pm
content: One non A type from this 14 Arrows stock is ordered an on the way to me.The sparrow in the hand, is better than pain in the b..., or so ...who knows what else will happen

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 17, 2017, 12:59:36 am
content: Quote from: bopcph on January 18, 1970, 11:40:56 amthis forum would love to have access to *that* holy bookregards.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 17, 2017, 10:53:02 am
content: Quote from: DiligentMinds.com on November 16, 2017, 07:37:37 pmRadioactive contamination is not leading to popcorn noise. If at all one would get something like a few random errors in high densitiy DRAM of flash chips due to high energy alpha decay. Today most of those errors won't be visible due to chip internal error correction. So it is definitely not due to radioactive contamination.The 1/f and popcorn noise is more due to chemical contamination's and maybe crystal defects. This might be hard to track, as it can be really trace amounts, both in the fab and in the wafers. Especially popcorn noise is something about a single defect (e.g. wrong atom) sitting at a sensitive place. More such defects at not so sensitive places give a source of 1/f noise.Usually there is no way to get rid of trace contamination - it's all about starting clean and keep it clean. A common practice is removing some of the surface by etching to get rid of damages from cutting the wafers.In the early days they has a story about yield being much lower after lunch. The anecdote is they got the yield back up, when they offered free lunch, as they traced the problem back to copper contamination from the money the workers used to pay the lunch.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 17, 2017, 11:40:01 am
content: Quote from: DiligentMinds.com on November 16, 2017, 07:37:37 pmhello Ken,can you expound on "a lot of noise", ie; some measurement details? how far off-spec or in-spec?best regards.

author: bopcph
author_rank: Contributor
timestamp: November 17, 2017, 01:22:39 pm
content: Quote from: zhtoor on November 17, 2017, 12:59:36 amI will try to retrace my browser history

author: mimmus78
author_rank: Unknown
timestamp: November 17, 2017, 02:35:54 pm
content: Quote from: zhtoor on November 17, 2017, 11:40:01 amI was asking this too.Inviato dal mio Nexus 6P utilizzando Tapatalk

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 17, 2017, 07:28:13 pm
content: What is the source of "Some recent parts?"? How many are we talking about and what date codes?? Are these actual real parts from LT or authorized distributor? Was this on a known good PCB design?Normally it is -very- rare to see a real LT factory checked LTZ out of spec on a properly built board, and we've seen about zero of what you're talking about on recent batches this year. I think over the several hundred I can count the bad LTZ's on one or two fingers, and LT replaced them since they came directly from LT (They will also do that if they come from a real authorized distributor, but not if you bought them from some broker or eBay, etc).It is common to see the noise on these parts from the shady parts brokers / dealers trying to peddle the "floor sweeping" rejected / fake parts that somehow got legs and walked out of the fab, or sometimes someone got hold of some reject die and repackaged them. You can usually tell when the parts aren't sealed in the proper tray with the LT logo.Those "used" LTZ parts on eBay are a bit suspect also - you never know what blowtorch was used to get the parts demounted. You might get lucky and they are fine, and maybe not.We've always ordered direct from LT and never had any real problem.

author: Andreas
author_rank: Super Contributor
timestamp: November 17, 2017, 08:47:29 pm
content: Hello,noise testing is not cheap.So I guess that LT is only measuring wideband noise for a short time and not the 1/f noise in excess of 10 seconds during production.The closer you look the more noise you will find.I have also the impression that newer buried zeners (AD586/AD587) have more (popcorn) noise but I will have to verify this with older stock devices.My LTZ#5 DC 0945 via official distributor has also a lot of popcorn noise in excess of 2uV.If you look at the "right" 10 seconds measurement duration you will see only the typical 1.2uVpp noise.With best regardsAndreas

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 17, 2017, 09:14:27 pm
content: @Ken (?Dobkin), @MisterDiodesdoes anybody know the yield percentage on the LTZ1000 die?regards.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 17, 2017, 09:21:53 pm
content: Andreas,...that's why the datasheet clearly states "about 1.2uV noise". 2uV p-p is listed as max, and that data looks still in the ballpark of that. You also have take your measurement uncertainty into account and look at how far your experiment drifts in the same time frame, as well as the overall noise floor of your setup. Are you scanning other known Vrefs simultaneously to compare? When you're down at uV levels that helps to distinguish noise on a -single- device from your experiment setup noise. The earlier part of your data is quieter for sure, did something get switched on nearby?

author: Andreas
author_rank: Super Contributor
timestamp: November 17, 2017, 10:47:07 pm
content: Quote from: MisterDiodes on November 17, 2017, 09:21:53 pmNo,its clearly popcorn noise. And whole setup including scope is battery supplied.As I measure with a filter amplifier (HP = 0.1Hz) you see only the rising and falling edge as triangle pulsewhen the duration of the jump is longer than about 1 second.Noise floor is typical 100-120uVpp so far away from the 1.2uVpp of the LTZ. (see noise measurement thread).with best regardsAndreas

author: Kleinstein
author_rank: Super Contributor
timestamp: November 17, 2017, 11:11:48 pm
content: I would expect the LTZ1000 to be tested for a little longer than 10 seconds. It already needs some time to get a stable temperature - so no way to do a super fast test anyway. Popcorn noise is likely one of the more important reasons to do the checks and sort out failing units.However with popcorn noise is can be difficult to detect - especially that type of noise with more infrequent jumps. Chances are one would not notice this in a short interval of maybe 30 seconds. Those very low frequency popcorn cases are the really bad ones, as one never knows and longer averaging also does not help that much. With the more frequent and symmetric jumps, like in TIN's jummpy sample from Ebay one has in theory the chance to detect and even correct for this.

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 17, 2017, 11:22:27 pm
content: Quote from: Kleinstein on November 17, 2017, 11:11:48 pmhello,looks like the biggest bottleneck in the production of LTZ1000 would be effective noise testing.regards.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 18, 2017, 02:45:39 am
content: I still fail to see the big LTZ datasheet spec "Oops" in Andreas' data. That shows a part still within the realm of datasheet specs it looks to me: It's showing clearly a P-P value of ~2uV (equipment / experiment noise -floor- limits are not known) which is the datasheet value. Of course the longer you measure, the more likely you'll see more noise. Especially as 1/f creeps in. Double the measure time and you get another octave's worth of 1/f possibilities. If there is -some- popcorn noise, it will probably still be able to pass the LT quality check.The problem we saw before on just one or two parts was an excursion more like 6 or 8uV P-P across 10 sec - clearly out of spec. Those got replaced.DigilentMinds: Were you thinking about a bigger "oops" deviation from datasheet value? That's what I was curious about. How many parts and what date codes are we talking about??

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 18, 2017, 02:57:52 am
content: Quote from: MisterDiodes on November 18, 2017, 02:45:39 amhello,what *is* the LTZ1000 go/nogo quality check with respect to noise specifically?(maybe another thread about LTZ1000 noise testing is in order)regards.

author: Andreas
author_rank: Super Contributor
timestamp: November 18, 2017, 05:21:35 am
content: Quote from: Kleinstein on November 17, 2017, 11:11:48 pmRTFMNote 2: All testing is done at 25°C. Pulse testing is used for LTZ1000A tominimize temperature rise during testing.And against other data sheets like LT1021 or LT1236 there is no 100% noise testing specified.The newer data sheet of the newer "3rd generation buried zener" LT1027 already specifies a method with reduced testing timeNote 5: RMS noise is measured with an 8-pole bandpass filter with acenter frequency of 30Hz and a Q of 1.5. The filter output is then rectifiedand integrated for a fixed time period, resulting in an average, as opposedto RMS voltage. A correction factor is used to convert average to RMS.This value is then used to obtain RMS noise voltage in the 10Hz to 1000Hzfrequency band. This test also screens for low frequency "popcorn" noisewithin the bandwidth of the filter. Consult factory for 100% 0.1Hz to 10Hznoise testing.So the LT1027 is tested from around 22 -41 Hz (with minimum 50 ms testing time).(no 100% test specified).In the LTZ1000 datasheet there is no noise testing specified.(it is always more essential to know what is missing in a data sheet as that what is specced).with best regardsAndreas

author: zhtoor
author_rank: Frequent Contributor
timestamp: November 18, 2017, 07:34:22 am
content: Quote from: Andreas on November 18, 2017, 05:21:35 amhello andreas,your observation is very correct:-TNFM (There is No ****ing Manual with respect to noise testing of LTZ1000)best regards.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: November 18, 2017, 10:52:37 am
content: ...Except the datasheet does clearly states a 2uV p-p max noise, does it not? Which is what Andreas' part is doing, and I would say is operating properly - at least from the graph shown. The datasheet doesn't distinguish the "type" of noise, but you do get a boundary limit. That 2uV p-p limit is still <0.3ppm p-p on a 7.15V scale, and difficult to measure accurately especially as a real -absolute- value change.That noise level is also in the realm of contributing binding post thermals, air drafts, EMI and lots of other causes outside the LTZ can.DigilentMinds was referring to something I think operating farther -outside the bounds- of the datasheet limits, and that's something that piqued my interest. From what I've seen that doesn't happen often with LTZ's (on proper PCB, proper draft protection, noise shielding, etc.), and I was curious about the date codes of those parts involved, if known.

author: bopcph
author_rank: Contributor
timestamp: November 20, 2017, 04:57:22 pm
content: Quote from: MisterDiodes on November 18, 2017, 10:52:37 amI'm glad I don't have an 8½ digit DMM - even a LTZ1000 inside spec's ain't good enough to calibrate itThats a joke of causeBut you actually have to do better than 0.01 ppm to get uncertainties less than one LSD on an 8½ digit

author: zhtoor
author_rank: Frequent Contributor
timestamp: December 04, 2017, 11:57:43 am
content: hello,did anybody get LTZ1000's from linear, has the production line started ("ramped up") after material change?regards.-zia

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: December 04, 2017, 12:37:51 pm
content: Yes. At least we have a shipment on the way according to FedEx, due here 12/6.

author: chuckb
author_rank: Frequent Contributor
timestamp: December 04, 2017, 02:27:16 pm
content: I got my backordered Digikey parts on Saturday. Date code 1744.

author: mimmus78
author_rank: Unknown
timestamp: December 04, 2017, 02:41:40 pm
content: Ohh!!! I should have accepted exchange of a 732A for a LTZ1000A the week ago ...

author: beanflying
author_rank: Super Contributor
timestamp: December 05, 2017, 01:08:56 am
content: Quote from: chuckb on December 04, 2017, 02:27:16 pmHow long ago did you order them? Seems the couple I ordered early last week were not shipped from that lotCurrent backorder time from Digikey is at Feb next year.........

author: chuckb
author_rank: Frequent Contributor
timestamp: December 05, 2017, 01:56:48 am
content: Quote from: beanflying on December 05, 2017, 01:08:56 amI ordered these 3 months ago.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: December 05, 2017, 06:49:37 pm
content: Quote from: beanflying on December 05, 2017, 01:08:56 amThat's good - that DK lead time was listed April 2018 as of a few weeks ago. So it seems like they've shaved a couple months off the backlog.LT says they should be able to catch up on Vref orders in Dec / Jan.We have seen delays like this before. A lot depends on how many devices they ship out to the big players - LT has no real economic reason to sell LTZ's in onsie-twosie quantities but it's good that they do.

author: beanflying
author_rank: Super Contributor
timestamp: December 05, 2017, 11:12:32 pm
content: Will have to make do with the LM399's that arrived today as temporary playthingsWaiting on a stash of Vishay's from Texas Components for the LTZ's and another couple of projects too.

author: floobydust
author_rank: Super Contributor
timestamp: December 06, 2017, 05:19:47 am
content: Quote from: chuckb on December 04, 2017, 02:27:16 pmchuckb, any chance you can note country of origin on the paperwork for those parts.

author: beanflying
author_rank: Super Contributor
timestamp: December 06, 2017, 05:49:54 am
content: Tried to 'order' 100 from DigikeySeems like order now you get Early Feb and ongoing looks ok at this stage.4 2/10/201840 2/10/201856 2/15/2018

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: December 06, 2017, 11:58:11 pm
content: Just checked our LTZ1000A order (order direct at LT) rec'd 12/6. Date code week 45 of 2017, diffused Milpitas CA, USA, assembled Malaysia, tested Milpitas.Every device 100% tested at LT Milpitas, CA USA, shipped from Milpitas and every device is guaranteed to meet datasheet specs, as signed off by LT. Certificate in the shipping package.Everything is correct and exactly as expected.

author: beanflying
author_rank: Super Contributor
timestamp: December 07, 2017, 12:01:42 am
content: I looked at buying these and a few other bits from LT direct but $90USD export freight is crazy money.

author: chuckb
author_rank: Frequent Contributor
timestamp: December 07, 2017, 09:56:59 pm
content: I ordered some LTZ1000As directly from Linear Tech on July 11, 2017. They arrived today. Date code 1744.Country of Origin, Malaysia.

author: mimmus78
author_rank: Unknown
timestamp: December 20, 2017, 11:24:39 am
content: I ordered some LTZ1000A from Digikey ... shipping 27/12

author: d-smes
author_rank: Regular Contributor
timestamp: December 20, 2017, 11:56:35 am
content: Quote from: mimmus78 on December 20, 2017, 11:24:39 amWhen did you order them? For me just now, DigiKey shows zero stock and 12 week standard leadtime. But when you try to order one, they show an "estimated" ship date of 2/15/2018...

author: mimmus78
author_rank: Unknown
timestamp: December 20, 2017, 12:02:36 pm
content: Quote from: d-smes on December 20, 2017, 11:56:35 amNow, just ordered. They changed date from 27 to 28 after the payment ... maybe I got the last two of this batch.Hope it's not an error.

author: mimmus78
author_rank: Unknown
timestamp: December 20, 2017, 12:07:45 pm
content: And if I try to reoder it's Feb/15/2018 ..

author: The Soulman
author_rank: Super Contributor
timestamp: December 20, 2017, 12:34:26 pm
content: Arrow shows 9 non-Ain stock:https://www.arrow.com/en/products/ltz1000chpbf/linear-technologyEdit: emphasized "in-stock".

author: TheSteve
author_rank: Unknown
timestamp: December 20, 2017, 10:19:31 pm
content: Quote from: Flinstone on December 20, 2017, 10:05:58 pmHah, there automated systems must have noticed the extended backorder time, figured there was huge demand and decided they needed it as a product.

author: cellularmitosis
author_rank: Unknown
timestamp: December 28, 2017, 08:21:50 pm
content: Looks like the Digikey Dec. 27th re-stock date slipped.

author: mimmus78
author_rank: Unknown
timestamp: December 28, 2017, 10:51:20 pm
content: Quote from: cellularmitosis on December 28, 2017, 08:21:50 pmYes I know :-) Mine were scheduled for today but not shipped too ...I tried to contact them by chat but the site keep going in error 404I'll check again tomorrow.

author: hwj-d
author_rank: Frequent Contributor
timestamp: December 29, 2017, 01:07:27 am
content: I ordered one A-type from hifi just to test it, but first need additional components too. Got it today.Has anyone already had experience with these?

author: cellularmitosis
author_rank: Unknown
timestamp: December 29, 2017, 02:31:22 am
content: Yeah, I’ve got three of them. They appear to work, but I haven’t dialed in my setup enough to look for popcorn noise.

author: beanflying
author_rank: Super Contributor
timestamp: December 29, 2017, 02:41:06 am
content: Showing as shipment 'overdue' so maybe they have secured some ahead of the February ETA? My two were in the Feb Lot?

author: TiN
author_rank: Super Contributor
timestamp: December 29, 2017, 03:53:18 am
content: 20pcs LTZ1000ACH, I've ordered direct from LTC are on their way, already shipped December 22.

author: beanflying
author_rank: Super Contributor
timestamp: December 29, 2017, 04:53:15 am
content: Sounds promising then, maybe Digikey's restock are on that batch too?

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: December 29, 2017, 05:13:24 am
content: If possible, just order direct from LT - it's usually a few weeks earlier than the distributors get them.Another early December order came in for us also - was here within about a week which is more normal.

author: beanflying
author_rank: Super Contributor
timestamp: December 29, 2017, 06:11:48 am
content: $90 USD export postage is a complete turnoff for 1's and 2's

author: kj7e
author_rank: Frequent Contributor
timestamp: December 29, 2017, 02:25:15 pm
content: New old stock?https://www.ebay.com/itm/NEW-Genuine-Linear-Technology-LTZ1000ACH-Ultra-Precision-Reference/253083175317?epid=1728172657&hash=item3aeceec995:g:BgcAAOxyzqdTdN4z

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: December 29, 2017, 06:20:15 pm
content: Not likely - at least when I talked to the seller he had no packing list or invoice from LT and he is repackaging them. He is NOT an authorized distributor so LT won't stand behind the part. Out of curiosity - the more I asked about the source of these it became more and more sketchy. It sounds like these -could- be some reject that slipped out of LT's control? Or they might be fine - hard to say. There was nothing about his supply chain story that inspired any confidence. I'll pass.Buyer beware. I suggest you just order from LT direct (if you can) - you're not really saving anything in the big picture, and the rest of the parts are expensive anyway...why risk your time and effort on a possible reject part? You're probably don't want to buy just 1 or 2 either if you're a serious student of low ppm ...the more Vrefs the merrier, so get 5 or 10 LTZ's at least (lowers shipping cost per part). Keep the best performers and give the rest away to your Volt-Nut buds.

author: mimmus78
author_rank: Unknown
timestamp: December 29, 2017, 06:32:34 pm
content: I Contacted digikey ... they just received some LTZ1000A today. They told me most probably they will ship my two today.UPDATE: LTZ1000A shipped

author: beanflying
author_rank: Super Contributor
timestamp: December 29, 2017, 11:01:47 pm
content: My poor post Christmas much abused Card was siphoned overnight for my couple of LTZ's

author: cellularmitosis
author_rank: Unknown
timestamp: December 30, 2017, 01:37:35 am
content: Quote from: mimmus78 on December 29, 2017, 06:32:34 pmMine shipped as well! Looks like their product page shows 29 LTZ1000A in stock.

author: hwj-d
author_rank: Frequent Contributor
timestamp: December 30, 2017, 03:46:10 am
content: Quote from: cellularmitosis on December 30, 2017, 01:37:35 amWow, ordered three for me.

author: Echo88
author_rank: Frequent Contributor
timestamp: December 30, 2017, 11:40:44 am
content: I also ordered 6 LTZ1000A on 28.12, which shipped today.

author: beanflying
author_rank: Super Contributor
timestamp: January 04, 2018, 03:49:55 am
content: Digikey proving once again having shares in a cardboard or packaging factory

author: Echo88
author_rank: Frequent Contributor
timestamp: January 04, 2018, 11:51:00 am
content: Considering they cost 55€/piece, i would have thought they also would be delivered by grey-bearded nude virgins from Utopialand. But it was just the normal UPS-guy.

author: hwj-d
author_rank: Frequent Contributor
timestamp: January 04, 2018, 01:39:09 pm
content: Quote from: Echo88 on January 04, 2018, 11:51:00 amWhat for phantasy do you have for this pity money?

author: Andreas
author_rank: Super Contributor
timestamp: January 04, 2018, 02:54:29 pm
content: Quote from: cellularmitosis on December 30, 2017, 01:37:35 amonly 2 left.my 2 have datecode 1750with best regardsAndreas

author: kj7e
author_rank: Frequent Contributor
timestamp: January 05, 2018, 03:21:49 pm
content: I have one of the new 1750 date code A parts, voltage seems a bit low compared to my others, 7.105...

author: mimmus78
author_rank: Unknown
timestamp: January 05, 2018, 05:26:35 pm
content: My too have 1750 ... but I don't know voltage yet ... still waiting some resistors from China! Dammed post service.

author: cellularmitosis
author_rank: Unknown
timestamp: January 06, 2018, 12:49:50 am
content: Quote from: Andreas on January 04, 2018, 02:54:29 pmthose went quick!

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 06, 2018, 01:58:41 am
content: Mouser shows:LTZ1000CH#PBF 12 in stock and none on order.LTZ1000ACH#PBF 59 on order, due on 05-Feb-18

author: beanflying
author_rank: Super Contributor
timestamp: January 06, 2018, 05:42:55 am
content: Quote from: Richard Crowley on January 06, 2018, 01:58:41 amWhen I ordered mine Mouser said non stocked itemAs what has been said above there crawler algorithm has likely figured out there is $$ to be made selling them.Better for us to have several sources available for 1's and 2's.

author: cellularmitosis
author_rank: Unknown
timestamp: January 07, 2018, 06:16:34 am
content: Rollin' on 1750's!(sorry, couldn't resist)

author: TiN
author_rank: Super Contributor
timestamp: January 07, 2018, 03:02:24 pm
content: Unpacked boxes today, so here are my candies:3 x 1745's17 x 1748's

author: kj7e
author_rank: Frequent Contributor
timestamp: January 07, 2018, 04:23:39 pm
content: Quote from: TiN on January 07, 2018, 03:02:24 pmI think your now on LT's the Christmas card list.

author: mimmus78
author_rank: Unknown
timestamp: January 11, 2018, 10:02:26 am
content: I think in a few years volt-nutting became like those wines estimator and start to say ...1745 is a bad week1743 is good week excellent with noise but a little bit of drifty, temperature coefficient is the lowest registered ever.The 1741 is the excellence: very low noise, good solderability and the lowest drift ... those references leaves a slight smell of cinnamon on second layer of the PCB and do not fear mitigated temperature changes. Keep at temperature of 40°C before using, but better served at 50°C.

author: hwj-d
author_rank: Frequent Contributor
timestamp: January 11, 2018, 11:25:06 am
content: So, I'm happy to have gotten this delicious 1750'er last autumn sun matured

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: January 12, 2018, 12:59:34 am
content: For anyone interested - DigiKey now is showing 197 pieces in stock this afternoon. Next shipment due 4/25 if you need 200.Now's the tiime to start that Vref factory you've always dreamed about....or build that 144 unit reference parallel Vref board, all in the name of chasing low ppmGood luck!

author: beanflying
author_rank: Super Contributor
timestamp: January 12, 2018, 02:06:11 am
content: Mmm I have a spare boardmaybe just one more and some Mr Pettis Resistors this time

author: Andreas
author_rank: Super Contributor
timestamp: January 13, 2018, 08:30:39 am
content: Quote from: mimmus78 on January 11, 2018, 10:02:26 amThe excessive raw TC of the 1754 er LTZ1000A (chinese seller) could be only tamed by opposite behavior of 1522ers econistors.