fake opa627's in the wild.

[user18]

Quote:

Originally Posted by CountChoculaBot /img/forum/go_quote.gif Good pics of real OPA627BP's: OPA627BP Photo: Enlarged

All the lettering is blocked by the watermarks. I wonder if the ebay one's are legit. They were SOIC, i was tempted to buy a pair, but i don't really need them for anything.

 

[threepointone]

woooowwww--opa627s are STILL out of stock everywhere? is this the same outage from last year or so (haven't been checking up on these lately)?

thank god I've got a mini-stockpile of 'em =)

 

[ericj]

Quote:

Originally Posted by threepointone /img/forum/go_quote.gif woooowwww--opa627s are STILL out of stock everywhere? is this the same outage from last year or so (haven't been checking up on these lately)? thank god I've got a mini-stockpile of 'em =)

Well, digikey says their stock is 0, newark says their stock is 0, ti says their stock is 0, and hints that farnell uk might have 1 (one) part, but they're probably wrong because farnell, these days, is the UK wing of Newark. lead time for some opa627 parts is listed by Ti as "20+ weeks" and for others as "please call".

I interpret this as meaning that the difet production line is either busy with other things and/or down for maintenance. Remember that this is a very old production line with very small by modern standards 4" wafers.

 

[dr dougie]

Hmm another of the same seller's listings (that I linked above) has photos of fake OPA627BPs. link

Here's a photo of the ones I got from them.

 

[adamus]

heres the offical packages from TI

Top Side Marking for Part

 

[adamus]

and by the way, i have just been given a full refund no questions asked.

Again - if its cheaper than it should be, its not a 627!

 

[Vaughn]

Crap, I just bought a pair of those from DIYkits.
Interestingly, they tried to sell me LM4562's instead saying "they
were much better". This makes me wonder if they didn't know the
627's were fakes.

 

[adamus]

try them. They may be. Just measure the DC offset - its enough to kill you phones.

 

[tomb]

Quote:

Originally Posted by adamus /img/forum/go_quote.gif heres the offical packages from TI Top Side Marking for Part

Interesting. It looks like one might interpret from that legend that there's no such thing as a Burr-Brown chip without a center notch in the end.

 

[ericj]

Quote:

Originally Posted by CountChoculaBot /img/forum/go_quote.gif Good pics of real OPA627BP's: OPA627BP Photo: Enlarged

After looking at those pictures a bit longer, i'm going to say the last two images are fakes.

Two reasons.

1: dimple next to pin 1 on the 2nd to last picture has vertical sides. i've not seen this on any burr-brown chip bought from a licensed dealer. We do however see it on the OP's fakes.

2: The edges and corners on the top of both of the last two pics are sharp, as though they've been shaved or sanded down. plastic packaged chips generally have soft, rounded edges.

 

[ericj]

Quote:

Originally Posted by dr dougie /img/forum/go_quote.gif Hmm another of the same seller's listings (that I linked above) has photos of fake OPA627BPs. link Here's a photo of the ones I got from them.

Those markings and case style are very similar to my OPA637BP's, which appear to be genuine.

 

[splaz]

Wonder maybe if we should build up a gallery of known fakes and real parts for the more expensive op-amps.

I have a small stash of some of the cheaper TI/BB chips. The packages all vary slightly with them amongst the different types, like slightly different BB logos,some with all white lettering, some all brown, a few with the batch/date codes in white but the other in brown.

Apparently which factory they come from, age and of course variations within the different op-amp families leads to this ?

Oh and Farnell AU has a variant of the 627,SMD with very little stock (8)... but it costs $$$s.

 

[ericj]

Just been looking through my stash of opamps - no notch in the end + dimple with vertical sides is how every single NJM/JRC part i have is packaged.

Every BB part i have has a notch in the end. My opa2604's have a dimple with rounded sides as well.

Edit: I have a Ti TL082CP that has a package similar to the OP's parts. The dimple on the JRC parts is closer to the end of the chip than the OP's photos or the tl082 - and no notch. So, Ti does have a factory that produces this package style. Which is not to say that they've ever used it to make BB parts.

fwiw i have 1 spare opa627au (so-8) that i could part with. Also a 637bp, which is a superior part but only for gains over 5.

 

[dr dougie]

It's going to be difficult to tell fakes without dissolving the things down to see the IC. BB came out with the OPA627 in early 1991 I think, then TI bought BB in 2000 and they kept making them until 2006(?). So they were made in at least several fab plants over about 15 years and the TI marking guide wouldn't apply for the chips made before 2000 and who knows if all the plants even used the TI marking guidelines afterwards?

TI would probably say the code on mine is not legit (0018WM155 - I emailed them but have not heard back yet) but there have been a bunch of people that swear their OPA627BPs and APs with similar codes are the real thing obtained from Burr Brown. I don't know anything at all about pre-TI codes.

Also the OPA627 supposedly needed more sophisticated production methods than other chips (hence their high cost) and would be difficult to copy. There has been speculation for a long time that fake OPA627s could be remarked cheaper chips like OPA134s.

So ... I just don't know! The only way to be sure is to buy from TI or authorized dealers which is not currently possible as they've been out of stock for awhile. I will agree that the Burr Brown op amps I remember all have the side center notch, but some of their other chips do not have them.

Oh forgot to add that one giveaway of fakes is angled lettering as compared to the edges. No matter where the legit ones were made they would not have passed QC with angled lettering.

 

[ianp]

Quote:

Originally Posted by Vaughn /img/forum/go_quote.gif Crap, I just bought a pair of those from DIYkits. Interestingly, they tried to sell me LM4562's instead saying "they were much better". This makes me wonder if they didn't know the 627's were fakes.

I ordered them 03/25:

<p>

BB with no notches, which does not appear on this page Top Side Marking for Part Number: OPA627BP.

They sound OK too, but I have no way of knowing if they are true blue or not.