If a transistor is a solid state digital switch, how can it also function as an analog amplifier?

Question

If a transistor is a solid state digital switch, how can it also function as an analog amplifier?

In: 4

Answer 1

The transistor operates in two “modes” – a linear mode and a saturated mode.

Certain transistors are designed to have a wide linear operating area and biasing the transistor in this area allows it to behave like an amplifier.

Other transistors are designed to have a narrow linear operating area and they are easily used as switches.

Ultimately, for the practitioner, just calling something a “transistor” is more or less not helpful. You have to specify the exact kind of transistor and the circuit it operates in and what that transistor is supposed to do.