fab said:
I donot agree.....that lateral are better than verticals.....in audio
Actually my circuit was for vertical mosfets not for lateral types, but you can also use laterals but withsome aforementioned modifications.....
you can use baker clamp to reduce the Cross-conduction when clipping in HF occurs.. on the collectors of CB stage transistors using fast recovery diodes....
Re: Kanwar Circuit
Hi FAB,
The CB stage doesnot invert the phase, the phase inversion takes place at the output stage with mosfets in common source configuration...
Yes, the CB stage is of much significance in my circuit...
1. It helps in providing the level shifting of signal..
2. It provides voltage gain
3. It is fast because of absence of miller effect, thus giving high slewrate
4. It doesnot stick the waveform to its rail in the case of Clipping, so there is no need of extra anti-saturation diodes ...
5. It act as a summing junction for local feedback loop, which again linearizes the output signal...
hope that helps...
K a n w a r
fab said:
Hi FAB,
The CB stage doesnot invert the phase, the phase inversion takes place at the output stage with mosfets in common source configuration...
Yes, the CB stage is of much significance in my circuit...
1. It helps in providing the level shifting of signal..
2. It provides voltage gain
3. It is fast because of absence of miller effect, thus giving high slewrate
4. It doesnot stick the waveform to its rail in the case of Clipping, so there is no need of extra anti-saturation diodes ...
5. It act as a summing junction for local feedback loop, which again linearizes the output signal...
hope that helps...
K a n w a r
Re: Re: Kanwar Circuit
Hi Kanwar,
I have simulated your circuit (http://www.diyaudio.com/forums/showthread.php?postid=1105696#post1105696 ) w/o the op-amp input to show you what I mean. First the circuit...
Workhorse said:
Hi Kanwar,
I have simulated your circuit (http://www.diyaudio.com/forums/showthread.php?postid=1105696#post1105696 ) w/o the op-amp input to show you what I mean. First the circuit...
Attachments
Workhorse said:
In http://www.diyaudio.com/forums/showthread.php?postid=1106511#post1106511 ,
I think R110 was much too low...I changed it to 47k and now it works!
In fact I am not sure what should be the "best" value for R110 and R114. In this configuration what is really the CFP gain ?
Attachments
fab said:
you should try to add some more JFET op-amps and other op-amps to your models
it is so old, that with wide Bandwidth they mean the following:
• Wide gain bandwidth: 4 MHz
• High slew rate: 13 V/µs
• Low supply current: 1.8 mA
• Low input noise voltage: 25 nV
Even if the old LF351 is not a bad op-amp,
neither 4 MHz or 25 nV noise are very impressive values.
Not even for audio applications = low frequency.
Regards
lineup
Workhorse said:
Is there a practical way to hve this configuration to work with a lower CFP "local" feedback gain for the goal of having the output section more invariant to load impedance (that is the goal of my initial circuit with low LOCAL feedback gain)? I guess that would mean to increase substancially the output section open loop gain... With high gm mosfet transistors (vertical) that is less of a problem then with low gm ones (lateral)....
lineup said:
Hi lineup,
thanks to remind me to pay more attention to the model I use...it is just that I could not find additional models for my old Microcap 6 version...Also, I am not that familiar to add new models in this software...(except adding all parameters manually which is a pain since the terminology used in the software is confusing with the one I learned or found in the datasheets...
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