LM399AH#PBF - Low stock worldwide - I need qty=30

[IanJ]

Hi all,

Anyone got a bunch of LM399AH#PBF for sale.......stocks are low worldwide and I could do with 30 at least asap. Digikey are saying 16 weeks, same on Analog Devices website.

According to Octopart, LTL Group have qty=2913 and i have emailed them.....but having never used them I don't know how reliable etc.

Ian.

[Kleinstein]

Mouser in Germany still show some 550 pieces in stock, and few more of the non A version.

[Jay_Diddy_B]

Ian,

I am not sure I get mixed information from my searching:

From LTL website I get:

[ Specified attachment is not available ]

From Google Maps I get:



This doesn't look promising at all.

But I also get:



You can read the rest here:
https://www.dnb.com/business-directory/company-profiles.leading_testing_laboratories_llc.27a169c3c6a47fffdc88c334f7cf3c7b.html

Regards,
Jay_Diddy_B

[wraper]

Mouser in Germany still show some 550 pieces in stock, and few more of the non A version.

They are not in stock. Expected around December.

[razvan784]

Why not buy some LM399H and maybe sort through them?

[IanJ]

LTL are suggested on Octopart......does that mean vetted?

[Andreas]

Why not buy some LM399H and maybe sort through them?

Hello,

I do not think that there is a large difference between A and non A type when being used near room temperature.
It is more a issue when they are being used at the temperature extremes.

with best regards

Andreas

[IanJ]

Hi all

Stupid question......usually part number I buy is LM399AH#PBF

Whats the #PBF part, lots of sites have it. Scared I get sent without thermal shield......

Touchstone-sys.com per Octopart said they can get me 50off $21usd.....2-3 days.

Ian.

[wraper]

Whats the #PBF part, lots of sites have it. Scared I get sent without thermal shield......

Lead-free

[martinr33]

Might try these folks.

https://bristolelectronics.com/lm399ah-linear-tech?___SID=U

[IanJ]

Might try these folks.

https://bristolelectronics.com/lm399ah-linear-tech?___SID=U

Thanks......have you used them?

[IanJ]

Another question as I contemplate buying from companies I have never used or heard of.......is the LM399AH always sold with the thermal shield.......would hate to receive without.

Ian.

[IanJ]

Hi all,

Melinda Berry, Touchstone Systems per the link at Octopart says they have available. This seller appears to be legit as there are one or two reviews etc. Hmmmmmm!

Was also wondering.......are there fake LM399AH's going around.....I ask because there are sellers from China selling on Ebay £4.66 ($6.12) each.

Ian.

[wraper]

Was also wondering.......are there fake LM399AH's going around.....I ask because there are sellers from China selling on Ebay £4.66 ($6.12) each.

Many of them may be LM399H remarked as LM399AH. Also many of them are salvaged ICs with new iron legs welded on top of kovar to make them look new.

[The Soulman]

Mouser in Germany still show some 550 pieces in stock, and few more of the non A version.

AH are on order ata december 2020.
H are indeed in stock, 395pcs (7-8-2020)

[martinr33]

I have not used Bristol, but they look legit. Line card, photos of a facility that looks plausible. They are worth a call.

When you use a Chinese supplier, there's a good chance that you will get refurbs or remarks. Marking up to the A version costs nothing more than regular, and attracts a higher price.

 

[Andreas]

Hello Ian,

for production I would only use parts from authorized distributors.

Findchips distinguishes between authorized distributors and independent dealers/brokers.

https://www.findchips.com/search/lm399

when measuring over 15 to 40 deg C with a LM399 (non A) I have typically a zero T.C. or up to 2 ppm over a 25 deg C range.
From 5 samples the worst case was 40uV (20uV after 2:1 divider) = 6 ppm over 25 deg C range giving less than the "typical 0.3ppm/K" from the data sheet.

with best regards

Andreas

[IanJ]

Thanks for all the help and suggestions folks......

I am just too nervous to buy from a non authorised dealer.....who knows what I'd get if I did get anything. Yes it's for production.

Also not happy at using the non-A 2ppm version, the selling point of my voltage sources is partly the stability and I advertise it with the AH version.....and it would play on my mind too much.

Guess I just wait for stock.

Frustrating thing is I just bought 25 from Digikey just a few weeks ago......if only I'd known.

PS. I have a begging email in with Analog Devices Inc......surely they have some in a drawer somewhere.....

Ian.

[Microcheap]

UTsource claims to have it in stock, certified and with a 90 days return and refund guarantee:

https://www.utsource.net/itm/p/11732139.html

[wraper]

UTsource claims to have it in stock, certified and with a 90 days return and refund guarantee:

https://www.utsource.net/itm/p/11732139.html

Utsource is not that much better than ebay and aliexpress. Full of counterfeit shit.

[IanJ]

Was also wondering.......are there fake LM399AH's going around.....I ask because there are sellers from China selling on Ebay £4.66 ($6.12) each.

Many of them may be LM399H remarked as LM399AH. Also many of them are salvaged ICs with new iron legs welded on top of kovar to make them look new.

I got a reply from Ebay seller, confirmed they were refurbished.

Ian.

[Kleinstein]

The LM399A should be just a graded version of the LM399.
With the 399 reference circuit changes are the TC depends more on the thermal design, than on the chip. One could do a crude binning before from the absolute voltage level. There is quite some correlation between the voltage and the TC without temperature stabilization.

Depending on the circuit it is used in one may do a little more grading / testing on the ready made circuit instead of a tighter binned reference.

[TheDefpom]

I would also suggest Arrow, I used them once (so far) and was very happy with the service etc.

Unfortunately LM399AH#PBF are not in stock right now either... https://www.arrow.com/en/products/lm399ahpbf/analog-devices

[TheDefpom]

In regards to UTsource, I have used them several times to get hard to find parts and never had an issue, just make sure you choose utsource certified original part as the supplier and not some 3rd party one which is also listed in the results.

UTsource show this for the item you want: https://utsource.net/itm/p/11732139.html

Personally I would be fine buying them from utsource.

[TheDefpom]

And of course if you get really desperate you can get the LM399H#PBF from RS UK: https://uk.rs-online.com/web/p/voltage-references/1450736/