And, English is my primary (only) language. I've been corrected on that before.... just habit I guess is hard to break. But we can understand it best within the context of the subject. Would not make sense much sense to compliment a topology.
Well, I do compliment CFA a lot for its good deeds.
-RM
ask Waly?
Modern ss CFA depend on cuurents for operation and thus lower internal voltages across devices - esp the non-linear C's --- a similar topology using higher Z values can be VFA with voltage controlled operation (tubes) but losses the benefit of current controlled and operated amps. One of the inherant reasons for CFA low HF distortion is the low voltage across devices and circuitry to limited voltage swings and derived distortion. My original circuit used low Z circuit values and higher than usual (for the time) currents. The circuits Z's were 100-1K max and then I saw the behaviour of the CFA in action.
Because you mentioned my name: what a pile of half baked stuff. Do I need to add that "lower internal voltages across non linear C's" has nothing to do with "CFA" or "VFA"?
And yes, the first "current feedback" amplifier was indeed built in the 40s, with tubes. We were shown the topology in an undergraduate course. And yes, Walt Jung is mentioned several times in the university courses, both at undergraduate and graduate levels, yours is unfortunately not. Sorry, yours is yet another "we did it 40 years ago" type of story.
Yes, I understand, it's a hard to swallow pill to hear this stuff straight from a young EE mouth, with little respect for anything but the truth. I know I can't persuade you to get a book and start reading, that would certainly look like admitting defeat
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They do not care about grammar - absolutely.
. And they do not care.That's the difference.
Because you mentioned my name: what a pile of half baked stuff. Do I need to add that "lower internal voltages across non linear C's" has nothing to do with "CFA" or "VFA"?
And yes, the first "current feedback" amplifier was indeed built in the 40s, with tubes. We were shown the topology in an undergraduate course. And yes, Walt Jung is mentioned several times in the university courses, both at undergraduate and graduate levels, yours is unfortunately not. Sorry, yours is yet another "we did it 40 years ago" type of story.
Yes, I understand, it's a hard to swallow pill to hear this stuff straight from a young EE mouth, with little respect for anything but the truth. I know I can't persuade you to get a book and start reading, that would certainly look like admitting defeat
I actually know what you are talking about as far as your making your point. I'm just not giving into it. And, if you dont understand mine for same reason, then fine. Or I have to think you do not know what you are talking about. Get beyond topology.... dig deeper.
THx-RNMarsh
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We're not terribly complimentary around here, so it's safe to assume the latter spelling even when not used.
I find it amusing no less.
WRT CFA/VFA: who cares, ultimately? There seems more than enough good ways to skin a cat that it's all lily gilding and arbitrary specmanship.
Think dynamic and how is changed the base emitter voltage when input signal is applied to the base and feedback of near the same voltage to the emitter of the same transistor in the same time. And think currents. You will understand the "expansive" behavior of CFA vs compresive one of the VFA where is most of the difference.
My sun use to say to me: "The world don't existed before my birth, reason you are born old."
The difference with you is he have the sens of humor, try to enter in the other's thoughts and that's a prof of intelligence. "Understanding (comprendre) is "make of a concept a part of you", or "take with you" (com-prendre in french). You ? you just "under"-"stand". and, for now, the burden looks too heavy for your shoulders.
May I suggest-you to take sometime to learn a little philosophy, to get a little education, before to use the mathematical formulas that you were taught as weapons you don't control, believing in it without any verification.
And be a little more respectful to people with around the same number of neurons than you and a LOT more of experience because real culture is not a matter of studies, but just comes with time and curiosity. For now, you act just like a haughty teenager, sorry to have to tell-you this.
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"Driving electric charge into high impedance nodes will result in large voltage excursion, whilst charge-driven into low impedance nodes will result in small-voltage excursion."
Now, in most writings this gets related to BW.... parasitic's move the poles to a higher freq. BUT for me, it also meant lower potential for distortion when going to CFA. Especially, when the large voltage excursions are across parasitic C's.
When processing technologies allowed for better NPN-PNP matches, then the CMA started to come into its own.
Waly, did you read any of the books/sources I put up on the What is a CFA forum? One early, but important over-view of the technology was published in 1994. Did you read it then? "Emerging techniques For High frequency BJT Amplifier Design: The Current-Mode perspective." by C.Toumazou, J. Lidgey & A.Payne. 1994 First International Conference on Electronic Circuits and Systems. Cairo, Egypt. Not the latest but fundemental stuff.
More to Esperado's point -- Also, remember what Damir said to your question about how he figured out his circuit..... knowledge from experience. And, most of it isnt written down in books, unfortunately.
THx-RNMarsh
Now, in most writings this gets related to BW.... parasitic's move the poles to a higher freq. BUT for me, it also meant lower potential for distortion when going to CFA. Especially, when the large voltage excursions are across parasitic C's.
When processing technologies allowed for better NPN-PNP matches, then the CMA started to come into its own.
Waly, did you read any of the books/sources I put up on the What is a CFA forum? One early, but important over-view of the technology was published in 1994. Did you read it then? "Emerging techniques For High frequency BJT Amplifier Design: The Current-Mode perspective." by C.Toumazou, J. Lidgey & A.Payne. 1994 First International Conference on Electronic Circuits and Systems. Cairo, Egypt. Not the latest but fundemental stuff.
More to Esperado's point -- Also, remember what Damir said to your question about how he figured out his circuit..... knowledge from experience. And, most of it isnt written down in books, unfortunately.
THx-RNMarsh
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