Understanding Current Gain in Push-Pull Amplifiers

[saad87]

I'm trying to figure out the currubt gain for a class ab push pull amp. I know that it's basically two emitter followers, so am I correct in assuming that the current gain is just Beta?

 

[Studiot]

the current gain is basically the emitter current over the base curent

$$\frac{{{i_e}}}{{{i_b}}}\quad = \quad {h_{fe}} + 1$$

With darlingtons you can forget the 1, but it can be significant with single transistors at high currents where the gain is maybe not more than 10.