"MiB-AE" (alien edition)
It's official (it works).
A strange "alien" folded cascode will be born.
More to come. (tonight) A good eerie nightime IPS. oooooh!
Another "brother" for the "spook". (fully symmetric). 😎
Oh - days pass by , It's my birthday - 6/11. celebrate? ... I don't know, @ 51 !
OS
It's official (it works).
A strange "alien" folded cascode will be born.
More to come. (tonight) A good eerie nightime IPS. oooooh!
Another "brother" for the "spook". (fully symmetric). 😎
Oh - days pass by , It's my birthday - 6/11. celebrate? ... I don't know, @ 51 !
OS
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Thanks , guys .. I'll try (going to town - Gatlinburg).
Makes me happy if my kids have a good time there. 😎
(Gatlinburg,TN is like a 365 day fair/party).
OS
Makes me happy if my kids have a good time there. 😎
(Gatlinburg,TN is like a 365 day fair/party).
OS
May this special day be filled with joy and laughter,
And may all the year, with OSs creations, be a very happy after!
Happy birthday man 😀😀
😀
And may all the year, with OSs creations, be a very happy after!
Happy birthday man 😀😀
😀
I'm at loss of creativity compared to our resident "alien". 😱 Mr. Miib has
one HELL of an IPS !
(below) -
what I do understand ....
- folded cascode is "smokin' fast . IPS has 2.3mhz unity gain
crossover point. Fast as any CFA.
- Current mirrored input pairs have quite the trans-conductance. They need
to , with a folded cascode VAS. 14db gain margin at 20K = 10ppm 😎 .
- The mirrors have a low Vceo (3V) , 7+ma will actually be "easy on them".
Better BCxxx 's can be used here - a further refinement.
I do not understand the other "self balancing" aspects. Perhaps this can
be explained further ??
PS - CCS referenced to ground is inferior to a rail reference -120db symetri vs.
100db for the "alien" ?? THD was slightly better on the "alien" Slew was impressive !!
OS
Attachments
Thank you all !!
Right now , I'm just a "kid" in Miib's "candy store".
This IPS is more than strange (alien) - I named it right. 😀
OS
Right now , I'm just a "kid" in Miib's "candy store".
This IPS is more than strange (alien) - I named it right. 😀
OS
I was having similar thoughts another day.
There should be no show stoppers for building great things.
Although if we are taking the design straight away, we should be definitely checking with an author.
If we are to become as restricted as corporate worlds, we won't be able to make a step.
You can even read windows EULA which says you are responsible for any issue that would happen with it 🙂
So don't bother and keep building great things. We are all learners here and unless we are cloning the stuff without the permission, this is some kind of adoption and development.
You can think of it as these works have inspired your job, sometimes you can get part of it and adopt, and most likely it might require some informal blessing from the initial designer. In other way if you have adopted the idea not the full circuit, there is no straight line to be drawn here 🙂
Keep living and keep creating 🙂
AE is a very interesting IPS-VAS stage! The VAS stage perhaps could be seen, rather than a folded cascode construction, as a complementary common-B stage, or a trans-impedance stage having a current gain close to unity. It takes output current of the complementary input stage that gets forcefully injected into emitter of Q8/Q10 by their respective current mirrors. Because of this construction, the simple Miller compensation is not applicable, as far as I understand. The idle current of all transistors are well defined by the CCS Q33/Q34 through the current mirrors and their interaction. For example, the VAS transistors Q8/Q10 has an Ie at about 2x tail current of the input pair, at 5.92mA, and seems to have good tolerance to transistor mismatch. Apparently such a full-complementary, current mirror loaded input-VAS stage does not suffer from the infamous VAS current instability problem well discussed in this forum as well as by Bob Cordell in his book (Figure 7.9), that would plague full-complementary current mirror loaded IPS followed by a complementary common-E VAS.
It would be even more interesting to see how the circuit behave when followed by an output stage and FB loop closed. The compensation schemes and possibilities are also quite intriguing. Before having a chance putting it to simulator I personally have a bit of concern about the output impedance of the VAS being possibly higher than we would like it to be at high frequencies, which may not be a good news for 3EF OPS stability.
It would be even more interesting to see how the circuit behave when followed by an output stage and FB loop closed. The compensation schemes and possibilities are also quite intriguing. Before having a chance putting it to simulator I personally have a bit of concern about the output impedance of the VAS being possibly higher than we would like it to be at high frequencies, which may not be a good news for 3EF OPS stability.
I say no. Stuff gets disjointed. Better to have everything in one place so the search feature has a chance. We can always move some of it to the Slewmaster build thread once it has been tested and boards ordered.
