Bipolar Junction Transistors (BJT)

Thursday, 11 July 2019

2:26 PM

Operation Modes

Active Mode

(Most common)

One forward junction, one reverse junction.

Transistor functions as a current controlled constant current source.

 

If EB is forward biased, then transistor is forward active

• Strong electric field which sweeps minority carriers near the BC into the collector

 

 

If EB is reverse biased, then transistor is reverse active

 

Saturation Mode

Both junctions forward biased

// somewhere in the middle

 

Cut-off Mode

Both junctions reverse biased

No current flows in the transistor