Hi Jan...
More food for thought.......
http://web.mit.edu/klund/www/papers/ACC04_opcomp.pdf
Nelson....what is 'TAFKA'??
More food for thought.......
http://web.mit.edu/klund/www/papers/ACC04_opcomp.pdf
Nelson....what is 'TAFKA'??
Re: Who cares whether it is current or voltage.......
From what I hear SonnyA is _very_ pleased with his CFB amp http://mirand.dk
To please Jocko I can say this much: My QRV-06 headphone amp has an excellent sound reproduction but my power amp of model "Alexander" worked good but I never had the chance to really listen to it and also at that time I had not so good speakers. Jocko may be right but he may also be wrong.Jocko Homo said:
From what I hear SonnyA is _very_ pleased with his CFB amp http://mirand.dk
My take on this is that you have difficulties to take a ideal voltage feedback amp and a ideal current feedback amp and transform them into real circuits. The thing is to see how the feedback is applied. I have studied current feedback amps rather little, only for a year or so but I see a pattern in how the topology is described. There is no room for discussion really. It's like having opinions about Ohm's law.millwood said:
.. and yes JLH is a current feedback amp and Mr. John Linsley Hood knew what it all was about.
Charles Hansen said:
damn marketers,
a lot of other sins are just as gross. the tube superiority, mosfet superiority, no feedback, full symmetry, etc.
they all have their real advantages, and marketers tend to exaggerate them to sweep people's decision making.
the same wolf under different skins.
peranders said:
I thought I had stated my views earlier and that's why you proclaimed my lack of knowledge. Since I said essentially the same thing as "JLH" said about current feedback, so I was puzzled why the same statements would be perceived by you at two opposite extremes?
Maybe what is said doesn't matter but who said it does?
that would be a very sad state of affairs, wouldn't it?
peranders said:
I have provided my opinion extensively, with argumentation why. I have discussed the pro and cons with others, who had other positions. You, on the other hand, have not only failed so far to clearly indicate your position and why, but even failed to indicate that you have any clue at all what this/was all about.
Typical you to reply to a question with another one.
I must stop, you tend to ruin my days.
Jan Didden
peranders said:
I believe that's actually called transimpedance amplifier (current in, voltage out). a trransconductance amplifier takes voltage in and sends out current.
Granted, a lot of the times the two terms are used interchangeably.
But again, if you had gone through the links you provided to us (for us go thrhough), you will see the distinction between the two.
let us come to the point
Dear Jan,
this was again semantic question that had no relation to the tread topic.
Some time ago we come to a viewpoint that nonFB means the absence of the overall loop, or the loops that contain two or more gain stages. Otherwise the emitter degeneration, emitter follower, etc is excluded, as FB in these examples is essentially rapid. Am I right, Charles?
Yes, Jan, current feedback is technically wrong term, let us come to the point that "current feedback" means voltage feedback connected to current input of the input stage. The main virtue of such connection is that the input stage transconductance is varied _correspondently_ with feedback factor/gain, maintaining the bandwidth regardless of gain. Yes, so called "current feedback" was employed from the beginning of BJT era by injecting the feedback current in emitter of the first stage. Will you agree, Jan?
Dear Jan,
this was again semantic question that had no relation to the tread topic.
Some time ago we come to a viewpoint that nonFB means the absence of the overall loop, or the loops that contain two or more gain stages. Otherwise the emitter degeneration, emitter follower, etc is excluded, as FB in these examples is essentially rapid. Am I right, Charles?
Yes, Jan, current feedback is technically wrong term, let us come to the point that "current feedback" means voltage feedback connected to current input of the input stage. The main virtue of such connection is that the input stage transconductance is varied _correspondently_ with feedback factor/gain, maintaining the bandwidth regardless of gain. Yes, so called "current feedback" was employed from the beginning of BJT era by injecting the feedback current in emitter of the first stage. Will you agree, Jan?
Dimitri, now you are talking rubbish. You are saying the same as I did, a couple of posts up and I talked rubbish.
Frankly, I think the easiest way to see what sort of feedback it is, is to cut the feedback. By that it's easier to see if it's a transimpedance amp or a voltage amp.
Thank you millwood for correcting me. It's not often I use the word transimpedance. I use transconductance more often. But I knew at least what the amp should do!
Frankly, I think the easiest way to see what sort of feedback it is, is to cut the feedback. By that it's easier to see if it's a transimpedance amp or a voltage amp.
Thank you millwood for correcting me. It's not often I use the word transimpedance. I use transconductance more often.
But I knew at least what the amp should do!- Status
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