OPA627 identification problem

[rabbitz]

Could always get them from Soundlabs... not cheap but a reliable source.
http://www.soundlabsgroup.com.au/c/ICs/ICs.html

I've also bought some from http://www.futurlec.com.au/ and were the real deal.

 

[PMA]

Is there anything from the OPA627 topology and technology transferred to OPA827? I would appreciate an answer from the connoiseur, not DIY second-guessing from datasheet.

 

[peranders]

Reading says that they have a completely new technology, Silicone-Germanuim and my guess is that pretty much is changed but if you want accurate info here I'll guess you'll have contact TI directly. I have some connections through my job so if you don't get any answers I'll maybe able to help you.

 

[PMA]

Thanks for your answer. I tested several preliminary 827 samples in DIP-8 package. They seem to be completely new circuit, though one can see positive traces of the 627. The new part has even lower noise, excellent DC behaviour, but is a bit slower.

627 is still available, but I have also heard rumours about fakes, though it sounds improbable.

 

[peranders]

Re: Faster is Better?

Hi Scott, P-A,
faster is better for audio? A stubborn misconception IMO. I hate the sound of AD's new line of fast opamps on their new dielectrical process, designed by that cute lady!

Speed has often something to do with distortion at higher frequencies. I have never come to a conclusion that ADI is worse than others. I like them, AD8610/20 lately. Sorry Elso, you can't comment this.

 

[peranders]

PMA, if you really have to buy 627, they aren't particulary worth the price and the sum will get pretty high. Let's say you wanty 10,2 0 opamps, the cost will be Right now you'll have surely a dozen good audio opamps. A good part seems the LME49710 to be. OPA211 seems also to be quite interesting.

 

[PMA]

I measured lower distortion for OPA827, compared to 627. Even at 10kHz. Not dramatically lower, but lower.

 

[PMA]

PMA, if you really have to buy 627, they aren't particulary worth the price

I know they are expensive, despite that I buy them time after time.

Do not tell ne about 49710 and 211. I tested both and none of them meets my demands.

I need a mix of low noise, very low Ib, low distortion and reasonable speed. Nothing compares to 627, except for 827.

 

[PMA]

But we are in a direction where I did not intend to go. Maybe Scott might come with valuable post.

 

[peranders]

I need a mix of low noise, very low Ib, low distortion and reasonable speed. Nothing compares to 627, except for 827.

Why do you need very low Ib? AD8610 is not so bad.

 

[L700]

i found another type of wording of 627

 

[jitter]

check the bottom

I'd like to add something to this thread.

The company I work for has twice now come across a batch of counterfeit OPA627.
The fakes may be so good that that their shortcomings might only become apparent in critical applications.

If you have a number of the OPA627 of the same batch code, you might also want to check the bottom of the IC.
I remember that one of the fake batches had very convincing printing on the top, and despite the fact that they all carried the same batchcode, the small circle cast in the bottom side of the IC displayed several different countries of origin!
TI/BB confirmed that the batchcode on the fake batch was not theirs.

 

[SweatyMe]

That's my first post so hello everyone!

I can buy 627's, and my question is how do they look in your opinion? Are they authentic or fakes?

Regards!

 

[jitter]

Unfortunately looks alone will not reliably inform you if the components are genuine or counterfeit.

I work for an electronics company that assembles and tests electronics for a wide range of industrial customers, hence I get to see lots and lots of components. I can tell you that different batches of the same type and brand of IC can look quite different from eachother while still being the real thing. I will also tell you that some counterfeit products may look conspicuously different but others may look the same or even better than a genuine product! Genuine products also vary a lot, BTW!

Analog Devices doesn't really seem to adhere to uniformity across their range. I've seen the AD797 and AD829 (both conventional and SMD) change from the nice picture in their datasheet to a simple text printing without even the company logo on it! And yes, they're genuine.

I remember coming across a batch of the OPA627AM that looked fake (which it was) and a batch of the OPA627BP that looked real (which it wasn't). I've also seen batches of the OPA627BP that looked fake (careless printing) but were genuine.
Just like AD, BB also doesn't strictly adhere to uniformity. Compare the printing on an OPA350 with that of a recent OPA627 (the ones where the encircled R has been omitted), and you'll notice they look quite different.

The only way to be sure to get the real thing is to buy directly from an authorized dealer and definitely avoid brokers and other unconfirmed sources.