Transistors Flashcards
Transistor
A three terminal semiconductor device that can amplify an AC signal or be used as an electronic switch.
Amplification
The process of increasing the power, voltage or current by electronic means.
Base
A thin and very lightly doped region in a transistor. The base is sandwiched between the emitter and collector regions.
Collector
A large, moderately doped region in a transistor. The collector is the largest of all three transistor regions because it dissipates the most heat.
Emitter
The most heavily doped region in a transistor. Its function is to inject or emit current carriers into the base region.
Active Region
The region of operation where the collector in a transistor acts like a current source.
Breakdown Region
The region of transistor operation where a large undesired collector current flows as a result of the collector-base diode breaking down from excessive reverse bias voltage.
Cutoff
Is the region of transistor operation where the collector current is zero.
Saturation
Is the region of transistor operation where the collector current no longer increases with further increases in base current.
What are the four transistor operating regions?
In which of these regions is the collector current proportional to the base current?
Saturation, Breakdown, Cutoff and active
The Active region
What is the main difference between an npn and a pnp transistor
In an npn the main current carriers in the emitter and collector are electrons whereas the main current carriers in the base are holes. Opposite for pnp.
