I got very interested in these japanese design with a special stage which connects the diff input stage with the output. Could anyone explain a little bit more of the benefits of this weird connection?
http://www.f8.dion.ne.jp/~isiatama/index.htm
Translation help here (not very good but you will understand something)
http://babelfish.altavista.com/
http://www.f8.dion.ne.jp/~isiatama/index.htm
Translation help here (not very good but you will understand something)
http://babelfish.altavista.com/
hi~~
they are folded cascode connection..
i think it is same pass p/n 5376899 (fig.3 = 134,135,136,137)
how do think about it?
they are folded cascode connection..
i think it is same pass p/n 5376899 (fig.3 = 134,135,136,137)
how do think about it?
Mr. Nelson, do you read this? Can you explain the folded cascode (if the circuit I have in mind is a folded cascode)?
What are the pros and cons?
You can give a rather technical explaination.
What are the pros and cons?
You can give a rather technical explaination.
Folded cascode
Oh great...... The Nelson Pass amplifier designer school. Free tuition! Why don't you look at Mr. Pass's design articles at his websites and do a search on "cascode" on the forum search page. I think it is a little much to ask a question that broad to anyone on a forum.
H.H.
Oh great...... The Nelson Pass amplifier designer school. Free tuition! Why don't you look at Mr. Pass's design articles at his websites and do a search on "cascode" on the forum search page. I think it is a little much to ask a question that broad to anyone on a forum.
H.H.
Check A75 article http://passdiy.com/legacy.htm (starting from page 6). Folded cascode explained there.
HarryHaller, it's costs you nothing to be humble and nice...
Mr Nelson Pass seems to be a decent guy and I imagine he will answer if he feels like it and/or when he got time. I appreciate if any person have something to say in this matter.
I have searched but I haven't got any "meat on my bones" as we say in Sweden, about just this particular circuit.
Mr Nelson Pass seems to be a decent guy and I imagine he will answer if he feels like it and/or when he got time. I appreciate if any person have something to say in this matter.
I have searched but I haven't got any "meat on my bones" as we say in Sweden, about just this particular circuit.
I tend to agree with the noble Mr Haller here.
It is a bit much to ask and the subject has been discussed on the forum as far as I know and is discussed to some detail in the Pass A75 article (part 1). For more information on cascode we could also reference the document already supplied by Mr Pass on cascode amplifier design:
http://www.passlabs.com/pdf/cascode.pdf
/UrSv
It is a bit much to ask and the subject has been discussed on the forum as far as I know and is discussed to some detail in the Pass A75 article (part 1). For more information on cascode we could also reference the document already supplied by Mr Pass on cascode amplifier design:
http://www.passlabs.com/pdf/cascode.pdf
/UrSv
I think you missundertand me. I totally aware of the cascode circuit but what are the A1360 and A3423 in the schematics really? The japanese guy has no email address at his home page so it's hard to get in contact with him.
Off topic:
I am in trouble due to the fact that I was agreeing with Mr Haller (which I suppose COULD get me in to all sorts of trouble) or was it Per-Anders being referred to...
/UrSv
I am in trouble due to the fact that I was agreeing with Mr Haller (which I suppose COULD get me in to all sorts of trouble) or was it Per-Anders being referred to...
/UrSv
I have redrawn the schematic to see better. It seems to be a modified folded cascode circuit. I haven't figured out the difference (in performance) between a
regular diff stage + folded cascode
versus
diff stage + a regular high gain stage with regular cascode. like my overkill phone amp (see my homepage)
Have you checked the advanced cross connected emitter follower?
regular diff stage + folded cascode
versus
diff stage + a regular high gain stage with regular cascode. like my overkill phone amp (see my homepage)
Have you checked the advanced cross connected emitter follower?
I could be wrong ... as i have not analyzed the circuit (no no, no sims!) yet but you move you dominant pole away from the input stage (the currentmirrors) onto the collector of 2SA1360 and the 2SC3423.
You also get a higher gain this way because of the currentmirror. The currentmirror works as a active currentsource driving the cascode pair...
This way you use both legs of the input diff pairs. This will also double your slewrate in the circuit.
Sonny
You also get a higher gain this way because of the currentmirror. The currentmirror works as a active currentsource driving the cascode pair...
This way you use both legs of the input diff pairs. This will also double your slewrate in the circuit.
Sonny
You mean 2sa1360 and 2sc3423?? Folded cascode
This folded cascode is sitting on top of the cascodes (C1815 and A1015) for the jfet diff amps. I could explain the circuit but it would cost too much time and effort and people will complain about me anyway... I'm I the only one who thinks there are way too many parts in this thing?
H.H.
This folded cascode is sitting on top of the cascodes (C1815 and A1015) for the jfet diff amps. I could explain the circuit but it would cost too much time and effort and people will complain about me anyway... I'm I the only one who thinks there are way too many parts in this thing?
H.H.
uuuhhh!!? You mean the feedback loop ..wierd!
The feedback loop is the coolest thing about this amp. You can use a small film cap and still use low value feeback resistors so as not to run into input capacitance problems with the diff pair feedback input. I have used this several times and I love it.
H.H.
The feedback loop is the coolest thing about this amp. You can use a small film cap and still use low value feeback resistors so as not to run into input capacitance problems with the diff pair feedback input. I have used this several times and I love it.
H.H.
okay now i think i have got the idear of the feedback network... You do not need to use large value caps to block for DC gain.
Sonny
Sonny
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