1. Basic Electronics Ninth Edition Grob Schultz
©2002 The McGraw-Hill Companies

2. Transistor Amplifiers
Basic Electronics
Ninth Edition 30
CHAPTER
Transistor Amplifiers
©2003 The McGraw-Hill Companies

3. Topics Covered in Chapter 30
Circuit Configurations
Class A, B, or C Operation
Analysis of Common-Emitter (CE) Amplifier
Collector Characteristic Curves
Letter Symbols for Transistors

4. Topics Covered in Chapter 30
(continued)
FET Amplifiers
Types of Distortion
Negative Feedback
Troubleshooting Amplifier Circuits

5. Types of Amplifiers for Junction Transistors
Common-Emitter (CE)
phase inversion
voltage, current, and power gain
Common-Collector (CC)
no phase inversion
no voltage gain, but has current and power gain
Common-Base (CB)
no current gain, but has voltage and power gain

6. Common-Emitter AmplifierRL C1 C2 R2 RE

7. Common-Collector AmplifierRE

8. Common-Base AmplifierRL C2 C3 R2 RE C1

9. Classes of Operation Class A 360° conduction
least distortion, least efficient
Class B
180° conduction
Class C
less than 180° conduction
most distortion, most efficient

10. Class A Operation
360° conduction IC
Time
Collector Current Waveform

11. Class B Operation
180° conduction IC
Time
Collector Current Waveform

12. Class C Operation
 90° conduction IC
Time
Collector Current Waveform

13. Measuring Transistor Characteristics
VCE IB

14. Collector Family of Characteristic Curves2 4 6 8 10 12 14 16 18
VCE in Volts
IC in mA
20 mA
0 mA
100 mA
80 mA
60 mA
40 mA

15. Gain of Junction Transistors
Beta (b)
Defined as the ratio IC/IB
Determines the current gain of CE amplifiers
Typical values are 10 to 300
Alpha (a)
Defined as the ratio IC/IE
Values less than 1, typically 0.98 or 0.99

16. Transistor Gain 10 mA IC 100 mA IB 10.1 mA IE 100 10 = A mA I m b 99 .1 10 = mA I E C a
10.1 mA IE

17. Types of FET Amplifiers
Common-Source
Corresponds to a CE circuit for a junction transistor: signal inversion, voltage gain and power gain.
Common-Drain
Corresponds to a CC circuit for a junction transistor: no signal inversion, no voltage gain, has power gain.
Common-Gate
Corresponds to a CB circuit for a junction transistor: no signal inversion, voltage gain and power gain.

18. Common-Source AmplifierRL D G C2 C1 S R1 RS

19. Common-Drain AmplifierG C1 S R1 C2 RS

20. Common-Gate AmplifierRL D G C2 S C3 R1 RS C1