Freshman here, and I've been searching for an answer to this question, but I could not find any actual justifications yet. Basically, I am studying the concepts of a Darlington circuit, and saw that its current gain was really huge. My notion (and I hope I am correct) is that because the input current is passing through a transistor twice, that means that it gets amplified twice.
But what I also realized is that a Darlington circuit has a high input impedance! Now for that, I can't seem to find an answer to. Is it also because there are two resistors, so the total input impedance is the summation of transistor 1 and 2's input impedance?
Hope I can get some clarification. Thanks!