prelim elec m1

junction transistors

semiconductor device that can amplify electronic signals such as radio and television signals

bipolar

abbreviation for two polarities

transistor

combination of transfer resistor, to describe their mode of operation way back in the early days of development

bipolar junction transistors

semiconductor devices that amplify or switch electronic signals

silicon or germanium

type of material of layers of bjt

npn transistor

middle layer is p-type between two n-type layers

pnp transistor

middle layer is n-type between two p-type layers

emitter

layer that emits majority charge carriers

electrons

majority charge carriers

base

thin middle layer that controls the flow of current between emitter and collector

collector

layer that collects majority charge carriers emitted from emiter

common emitter

most common configuration due to high current gain and voltage gain, emitter is connected to ground, input to base, and output to collector

common base

high input impedance and low current gain, base is connected to ground, input to emitter, and output to collector

common collector

high input impedance and low voltage gain but can be used as voltage follower, collector connected to ground, input to base, and output to emitter

transistor

allow current to flow or stop like a switch and amplify an input signal, similar to electrical solenoid or relay

beta

crucial parameter of a bjt that measures current amplification capabilities, ratio of the collector current to base current in common emitter configuration