Simulation Questions:

[harry bissell]

In my case: these multiple emitter transistors seem to be some form of
current sources.  They bias multiple points so the idea of "spreading" a
certain amount of current makes sense.

Does anyone use EWB ??   Take a look at the CA3080 model. Does it make any
sense ??? NO !!! Also look at the LM2900 (norton) model.

What is this S#1T ???   These models are absolute bulls#it.  There's no
bias pin on the CA3080...  What did they do... take a 741 and have
schoolkids (monkeys? door knobs ??) copy the device parameters... well at
least the ones there were 'blanks' for...

Thanks... I'm done venting now.

:^) Harry

Martin Czech wrote:

> :::     >They are what they are ;->
> :::     >Common collector and base and multiple diffused emitters.
> :::     >You need the model of such a device. For simple analysis,
> :::     >just use parallel transistors. But this doesn't work, if
> :::     >the different emitters have different emitter area (which is
> :::     >used to partition current between the multiple emitters).
> :::
> :::I assume you still can get a decent approximation when you're simply
> :::connecting N transistors in parallel for the increased area.
>
> Yes, this should work (1st order, geometry?) , since the parallel
> transistors are idealy matching, ie. all equal. This will not work in
> reality (base potential?, rbe, beta).
>
> m.c.