I am under the general understanding that a Bipolar Junction Transistor is a current controlled current source, while a Field-Effect Transistor is a voltage controlled current source. But I don't understand why. I have read in numerous places that the relatively lower input impedance of the BJT, and the higher impedance of the JFET and MOSFET are the reason this distinction is true, but I don't understand that. Both the base of a BJT, and the gate of a FET require some amount of voltage and current to operate.
Anyone able to make shed some light on this?
Thanks!
Anyone able to make shed some light on this?
Thanks!