# TI and the Burr-Brown line

#### beenthere

Joined Apr 20, 2004
15,819
As ever, when ordering parts for an instrument, at least one part won't be in stock. In this case, it was the OPA134/2134PA op amp. Neither Digi-Key nor Mauser had them (lead time 27 weeks).

The last time this happened, TI was going through a RoHS cycle. But what is going on now? Every one of the Burr-Brown op amps that TI has continued in production seems to be unavailable - even the instrumentation amplifier line.

TI lists them as in production, but with no stock and lead times of 20 weeks. Only Rochester Electronics, a job lot dealer in obsolete devices seems to have stock.

Any guesses? None of the skims through the industry news has anything to say. If TI is going to just drop them, that is a big hole in the really useful and affordable op amp selection.

#### Wendy

Joined Mar 24, 2008
22,469
As a speculation, could it be someone has bought them up for a really big project? We're having a lot of cutbacks on military equipment, but other programs are full steam ahead and beyond.

#### R!f@@

Joined Apr 2, 2009
9,749
U know.. when speaking of bur brown, is it that these OPAMPS are superior to their counterparts.
I wonder what will happen if I switch to bur brown op amps in my crossover network.
Do u reaaaaally think that I could hear any difference.

Rifaa

#### beenthere

Joined Apr 20, 2004
15,819
As I have no idea which op amps you have currently in use, the question is essentially unanswerable. For audio work, there are several National and TI op amps with lower distortion than the OPA134, but hearing the difference after the first two decimal places is more a matter of imagination.

I find that op amp useful due to the 10^13 input impedance. I use it in the front end of an amplifier that is employed in studies of insects. That level of impedance is just right for the application. The company that is interested in building my instruments under license has rated it "the best biological amplifier in the world". The OPA134 is perhaps not crucial to maintaining the performance, but locating a substitute and verifying performance is no fun at all.

#### steveb

Joined Jul 3, 2008
2,436
If anyone ever needs a few Burr Brown OPA655 opamps, let me know. I can mail a few samples out to anyone in a bind. I've got 75000 of them sitting on my shelf gathering dust (don't ask why). I use them now and again, when I need fast response circuits, but I don't plan on living long enough to use them all.

#### Wendy

Joined Mar 24, 2008
22,469
Just curious, what is the typical price of these components?

#### steveb

Joined Jul 3, 2008
2,436
Just curious, what is the typical price of these components?
If you are referring to the OPA655, I'm not sure of the current price. They were in the $5.00 to$6.00 range many years back when I picked them up. They were part of a whole bunch of components I picked up for free. I have reels and reels of surface mount capacitors, resistors, transistors and obviously opamps.

By the way, I miscounted. I only have 25000 of them, and they are surface mount. I don't recommend them for audio work. They are better suited for video, CCD, photodiode transimpedance etc.

#### R!f@@

Joined Apr 2, 2009
9,749
@ steveb
I might buy some if u can give me the values u have and the tolerance levels.

@ Bill
by the way the opamps I have and uses are 4558 and TL074 and 084's

Rifaa

#### steveb

Joined Jul 3, 2008
2,436
@ steveb
I might buy some if u can give me the values u have and the tolerance levels.

I'm not trying to sell any components. I got them free and just use them for hobby and work. I'm just saying that if someone needs the Burr Brown OPA655, and can't get samples quickly, I can mail out a few free ones.

I'm just trying to help out given the problem that "beenthere" brought up.

#### Thav

Joined Oct 13, 2009
82
Hey, I was in with a TI sales rep recently and she mentioned that during the valley of the recession when everyone cut back their orders they did lose some capacity to layoffs and plant closure. They are supposedly opening a new plant that should bring lead time way back down. This was in context of DSPs and Unitrode products, but it may also apply to the Burr-Brown stuff.