Why are TI's chip amps (OPA549) six times the price of National's (LM38xx)?

[janneman]

If you guys talk about the multi-pin TO3 metal part, that explains at least part of the difference. TO3 is notoriously more expensive then plastic everywhere, and if you then add in the non-standard pinout the manufacturing price explodes.

Jan Didden

[bigparsnip]

Probably one of the reasons (appart from the hugely expensive metal packageing allredy mentioned) is the fact that the ti parts have FET input transistors, whereas the national parts are all bipolar. And, as it costs a lot more to mix bipolar and MOSFET technologies on the same piece of silicone, this will probably account for the majority of the price increace.

[jackinnj]

Originally posted by paulb

Right. Also, the OPA came from Burr-Brown, who were a smaller company that charged more, who were bought by TI. I believe the OPA was developed before the National parts and probably costs more to fab.

the OPA chips are great for programmable power supplies, high power oscillators -- like an opamp on steroids -- the LM3886 etc. are really designed with a specific gain in mind, SPIKE protection etc.

Burr-Brown -- I am pretty surprised that TI has kept most of this intact -- they were the "ne plus ultra" of linear design...

[Upupa Epops]

TO 3 notoriosly expensive than others . Why ? 2 N3055 is in classical TO 3 and mostly cost 0.3 buck. Are several holes up more in case TO 3 so expensive ? Where is the problem ? Or have this manufacturers so bad technology,that they must trow away tree of four chips ?

[janneman]

Originally posted by Upupa Epops
TO 3 notoriosly expensive than others . Why ? 2 N3055 is in classical TO 3 and mostly cost 0.3 buck. Are several holes up more in case TO 3 so expensive ? Where is the problem ? Or have this manufacturers so bad technology,that they must trow away tree of four chips ?

No, it's all in mass production. The modern plastic things can be very cheaply produced in relatively cheap machines. The metal parts are made in less quantities, and the machines are more expensive, so the price per part goes up even if the die inside is identical.

I would expect you will find that on average a TO3 2N3055 will be more expensive than a plastic MJ3055.

Edit: Digikey prices: 2N3055 TO3 $2.10 or $1,68 (depends on brand)
Plastic MJE3055 $0,84 or $1.01
All single prices, and MJE3055 is higher spec than 2N3055

Jan Didden

[nick_g_evans]

Originally posted by peranders
The LM38xx is aimed for a consumer market and the OPA541 for a professional market and has nothing to do with performance. I think this is the simple explanation.

This makes sense. Maybe they just don't sell very many of them.

[janneman]

Originally posted by nick_g_evans


quote:
Originally posted by peranders
The LM38xx is aimed for a consumer market and the OPA541 for a professional market and has nothing to do with performance. I think this is the simple explanation.


This makes sense. Maybe they just don't sell very many of them.

No it doesn't make sense. If they had the same performance, they would be the same and the price would be the same. If you built it for the professional market at a higher price that means you can only sell it if it performs better.

Jan Didden

[Upupa Epops]

What is " more expensive " , Jan ? One for 0.3 , other for 0.5 ? Both are for most of us funny cheap, 'cos we don't made industry production . Is cheap or expensive one hamburger ? Misery is somewhere else, than in this community.

[carlosfm]

The TO3 version I was talking about has 8 legs and two holes.
10 holes to mount them on a heatsink, and I did this.
Painful job, without the right tools.
The metal can must really be more expensive to produce, specially because they also have a "normal" version, wich is much easier to use and must as a consequense sell more, and again, if it sells more, it is produced in much more quantities, and gets cheaper to produce.

The beauty of these chips (even the TO3) is that the metal case (or tab) is isolated.
I made the wholes on the heatsinks and didn't use isolators, just thermal paste.
BB (now TI) even has sockets for the TO3 version.
Oh, yes, they are Fet inputs.
You will not have more than 1~2mv DC-offset on the outputs, as I do.
But LM chips sound better to me.
Oh, a pic of the chips:

[carlosfm]

Originally posted by Upupa Epops
TO 3 notoriosly expensive than others . Why ? 2 N3055 is in classical TO 3 and mostly cost 0.3 buck.

There are big disparities in price of the 2N3055.
I bought at around 0.7€ each (Toshiba), but the other day a guy at a local store asked me 8€ each!
I asked him if they were 24K gold plated?!