AW: Re: AW: Re: AW: Transistor matching

[Haible_Juergen#Tel2743]

> Juergen, we just look at this from two diffent perspectives... and there 
is no
> point in us building up arguments against each other...
> You asked an question and I gave my view...
[...]
> Currently I am quite tired of the flame-happines that exist on some other
> lists
> so I won't go into deep argument without a good reason. I will go back to 
my
> semiconductor book that I am supposed to do deep studies in anyhow...
> If you don't feel my views on the topic comply with yours just leave out, 
OK?

Oh. I did not intend anything like this.
Flames, argues, nothing of this kind.
I mean I asked a serious question, because
I *value* your (and the list's) comments - could
there be any doubt about that ?

It happens quite often that I am not sure about some idea
or circuit. Ok, I have thought about some 1st-order side
effects, but how can I be sure that I have taken *everything*
into account. You answered my question, and you gave
me an warning of some side-effect which I thought I had
already considerd, but not yet calculated. So now I calculated
the maximum current change, just to be sure, and found that
what originally was just a feeling, still held true in calculation.
Now I thought it was a good idea to share the calculation
with the list.
I think there is nothing like "I am right and you are wrong" about
it all. You helped me to to go deeper into the matter, and
(hopefully) both our posts were of some use for some other
list members who will also select transistors.
I am quite sure that this "first-order-side effect" that we discussed
is of no harm. But I am still *not* sure if there are other side effects
that I have not thought of, so far. After all, there *must* be some
reason that Moog used real current sources instead of resistors.
Perhaps there is a positive feedback loop that includes heating
effects? (Vbe getting smaller, and Ic increasing ...). I am not
sure if it has an effect at 100uA, but at least the temperature
coefficient would be opposite with real current sources!

I hope you see that my aim in discussion is deeper understanding,
and not arguing. Well, re-reading my posting with a sentence
like "Who needs an exact current of 100.00 uA ??" makes me
think if I have hit the right tone. I am not a native English speaker,
so sometimes I am happy when I can express the technical
stuff fairly like I intended - sorry if politeness comes short.
I never intended to be rude. I value your comments, and I hope
we will still get them in the future. Peace?

JH.