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Yes it can. The feedback makes it essentially an op amp, with the output voltage being a ratio to the input voltage. There will still be distortion, and the intermediate signals could be quite distorted, but the output should follow the input quite well, even though the driving signals for the final stage will not.
That said, a matched pair does make it easier and will probably reduce the distortion.
Bob
What made you think you can use anything but a matched pair?
To any Hi-Fi audio (class AB complimantry) power amp the Output Stage matched pair is a fundamental MUST requirement !!!
That is critical for "ultra high-end " LM4702 type circuit performance .
Here is a TI app note(your circuit is taken from it) dealing mostly with the performance of matched pairs from different vendors.(there is a summary of performance comparison on page 27).
I think it will help you a lot.
AN-1645 : LM4702 Driving a MOSFET Output Stage
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That application note seems to suggest the use of a pair of complimentary mosfets. A quick read does suggest they were a specifically matched pair. As I said, "a quick read", so I may have missed it.
It certainly seems that a gate driver for the mosfet to allow more than 3mA of gate drive improves transient response.
It certainly seems that a gate driver for the mosfet to allow more than 3mA of gate drive improves transient response.
thanks for your link
why can't you just adjust the gain on Rgn1 and Rgn2? isn't it there for that reason?
No,the gate resistors don't adjust gain.
Their purpose is totally different:
Maintain the Amp stability(prevent oscillations of the Amp.)
Look at section 7.1
I'm wondering, are you actually going to build the AMP?
To be able to build a ultra-HiFi High Power AMP needs a lot of Knowledge and experience...
And, to be able to test it's performance requires very expansive Hi-End test equipment,which I'm sure you don't have...
So what gives?
i am basing my design off of other peoples. i have decent knowledge, and quite some soldering and pcb experience. I don't have the budget to buy 1000 transistors just to pair it, i will probably buy paired transistors, so i don't need really high end test equipment. Even though people have suggested to not use usb scopes, i will be using a really hi-fi soundcard as a scope, as it's accuracy is pretty darn high. it won't be the the best solution, but it will work for now, i'm only working with frequencies from 20-20k.No,the gate resistors don't adjust gain.
Their purpose is totally different:
Maintain the Amp stability(prevent oscillations of the Amp.)
Look at section 7.1
I'm wondering, are you actually going to build the AMP?
To be able to build a ultra-HiFi High Power AMP needs a lot of Knowledge and experience...
And, to be able to test it's performance requires very expansive Hi-End test equipment,which I'm sure you don't have...
So what gives?
swagguy,
Your previous questions speak otherwise...
You don't have enough knowledge for this .
You may build it,but you don't understand how it works (not only in the finest details).
Buying 1000 Tr. and trying to match them?
That is a low level hobbyist attitude, miles away from the Pro one needed for such a high-end project.
What Trs are you going to use?
watch out for fakes!!!
"so i don't need really high end test equipment."
Another UN-knowledgeable statement.
You must ,otherwise you can't test it to spec.
sound card/usb scope are ...,
well almost total rubbish for testing an ULTRA HI-FI AMP.
You see,
the Key Factor here is ultra low distortion at relative high power...
I wish you success and enjoyable sound.
Do take care with does big caps you need for the PS.
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And I would personally look at the active driver solution using the transistors to drive the gates. Even with unmatched transistors, setting the bias current will go a great way to achieving a good result.
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