Regions of Operation of the Bipolar Transistor

Base-Emitter Junction

Base-Collector Junction

Forward Bias

Reverse Bias

Forward Bias

Saturation Region

(Closed Switch)

Forward-Active Region

(Normal-Active Region)

(Good Amplifier)

Reverse Bias

Reverse-Active Region

(Inverse-Active Region)

(Poor Amplifier)

Cutoff Region

(Open Switch)