> almost universally done incorrectly even in some high profile textbooks
In what way(s) do books tend to get it wrong, and is "The Art of Electronics" by Horowitz and Hill, which I'm currently reading, free of such errors?
In what way(s) do books tend to get it wrong, and is "The Art of Electronics" by Horowitz and Hill, which I'm currently reading, free of such errors?
The cardinal sin of teaching BJTs is to say that they're current-controlled amplifiers: little current in, big current out. They are not, not really. They're voltage-to-current converters: little voltage wiggle at Vbe, big current wiggle at Ic. This is really not in dispute and anyone who tries to argue for the hFE/beta model as really true is wrong. Certainly, it is a useful approximation and often all you need, but it is not how a BJT really works and so don't pretend it is.
(The link between the two is that the base is not a high impedance input. That is pretty uncommon, so it's not surprising that it's kind of confusing! Because it's a low-impedance input, small changes in applied Vbe correlate directly with small changes in current, so it looks current-controlled. But careful measurements, as I believe are plotted in AoE, reveal the primacy of the Vbe-controlled model.)