They could have done emitter-followers with PNP if
they'd wanted, but
I imagine at the time the difference between the dopants would have
been extreme enough that you'd get severe enough performance
degradation that NPN with a negative Vee was considered worthwhile.
It can still be a factor of 2 difference between P-type and N-type
these days.
Um. Wow. I had no idea the difference was that great. I'd felt sure
there would be a difference, simply because different dopaant atoms are
bound to have different properties, but I would have expected the
difference to be in the single-digit percentage range. That the
difference is more like a factor of two rather gasts my flabber.
Given that, I can see how the rest follows from it.
But now I'm curious. What sort of performance degradation does PNP
exhibit? Slower switching? Higher power dissipation? And what's the
underlying difference behind it, do you know?
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