1. Bipolar Junction Transistor
The principle of BJT
The configuration of basic BJT amplifier
How BJT amplifier works
How to model the BJT amplifier
How to analyze the BJT amplifier

2. Bipolar Junction Transistor
Transistor, a fundamental unit of a circuit
FET, MOSFET
BJT

3. Bipolar Junction Transistor
Can we make a transistor by
connecting two diodes?
Can we interchange emitter
and collector?

4. Bipolar Junction Transistor
Forward bias
Reverse bias

5. Basic BJT Amplifier Configuration
Common Emitter Configuration
Common Base Configuration
Common Collector Configuration

6. Current Relationships
Common Base Current Gain
Common Emitter Current Gain
From Definition,

7. Current-Voltage Characteristics
Common base circuit configuration

8. Current-Voltage Characteristics
Common emitter circuit configuration

9. Current-Voltage Characteristics
Early Voltage VA
Output resistance

10. Graphic Analysis Common emitter configuration
Q: DC bias point (quiescent point)
Load Line

11. Graphic Analysis Common emitter configuration
Q: DC bias point (quiescent point)
Load Line

12. BJT Amplifier

13. BJT Amplifier

14. BJT Amplifier
Amplifier Gain:

15. Small Signal Model Transconductance: Input Resistance at Base:
Voltage Gain:

16. Hybrid-∏ Model + -

17. Account for the Early-Effect
Output resistance

18. Equivalent Circuits (Common Emitter)
Input Resistance
Output Resistance

19. The T Model
Emitter Current:
The Input Resistance at Emitter:

20. The T Model
When considering the Early effect

21. Equivalent Circuits (Common Collector)

22. Equivalent Circuits (Common Collector)
Input Resistance
Output Resistance