Diferents ways of connecting and opamp?

[SISKO]

Hi, I'm know  theres is a topic in here where it is shown how to wire op amps in unusual ways (like, IIRC, input signal  was vss-pin, ground of the op was connected through the output pin, etc) but was unable to find it (saw it some years ago). I don't know what key words to use either. So my question basically concerns about whether if someone remembers that topic or has some usefull link about it. I'm just curious about this, just that (I mean, I'm not looking for anything specific)

Any info will be highly appreciated!

[R.G.]

TI published a technical paper entitled "Opamps for everyone". It will answer questions you have not thought of yet about opamps, and is a great place to start.

Try googling "opamps for everyone" and "ti.com".

[SISKO]

Wow R.G. a millions thanks to you!
A very nice paper to read and A LOT of information to digest!

Guess ill be busy for some time with this!

A *very* quick search trough the doc, revealed no info on connecting the op amp  in not so classical ways. Maybe I passed away the figure. Ill keep reading.
R.G. (or some other) do you know anything about this? Does it "ring the bell", or have seen anything like it? I mean, using the op amp with odds connections.

[PRR]

> connecting the op amp  in not so classical ways

Perhaps R.G. is telling you that, to know "not so classical ways" you should first know the "classical ways". BeBob is non-classical Jazz, but those BeBob cats knew their classical Jazz inside out and backwards.

Or maybe he is suggesting that "any" response can be synthesized with classical opamp systems.

Connect op-amps "wrong", mostly you get open-circuits, diodes, or short-circuits.

Yes, I know a few oddballs. "Output" grounded and real output taken from supply pins.

[Jorge_S]

TI published a technical paper entitled "Opamps for everyone". It will answer questions you have not thought of yet about opamps, and is a great place to start.

Try googling "opamps for everyone" and "ti.com".

R.G. are you talking about this doc?:

www.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=slod006b

I ask because there is another book with the same title at Google books...

thanks!

[teemuk]

Yes, I know a few oddballs. "Output" grounded and real output taken from supply pins.

And it's not even "oddball" at all. Basically it's still a standard opamp gain stage with normal configuration for inverting and non-inverting inputs, output configured to push-current to a lowish impedance load (no, you can't really drive a direct short with a generic opamp, you'll need a small load). The only exception is that instead of taking signal feed from the output pin as usual, the signal feed is taken by sampling the current draw of opamp's power supply pins.

[SISKO]

Perhaps R.G. is telling you that, to know "not so classical ways" you should first know the "classical ways".

Or maybe he is suggesting that "any" response can be synthesized with classical op amp systems.

I have no doubt about R.G.´s  knowledge nor yours and  I'm pretty sure I understand about 1% about op amps. I'm reading the document that R.G.  proposed and its really catching and has A LOT of information! A really nice lecture.

Anyway, as I stated earlier

I'm just curious about this, just that (I mean, I'm not looking for anything specific)

The idea of seen (in here) a picture of an op amp miss-conected arrived to my mind and wanted to know what was the fuzz about that. Yes, I'm very keen on learning op amps (this is why I appreciate the IT doc), but it was not my main aim.

Yes, I know a few oddballs. "Output" grounded and real output taken from supply pins.

And it's not even "oddball" at all. Basically it's still a standard op amp gain stage with normal configuration for inverting and non-inverting inputs, output configured to push-current to a lowish impedance load (no, you can't really drive a direct short with a generic opamp, you'll need a small load). The only exception is that instead of taking signal feed from the output pin as usual, the signal feed is taken by sampling the current draw of opamp's power supply pins.

This is *exactly* what i wanted to know! This was the figure I had in mind! Any info on how this connection is called, or where can I find more info?

[PRR]

> R.G. are you talking about this doc?:
www.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=slod006b

Yes.