Heaven’s light is our guide
Rajshahi University of Engineering & Technology
EEE 2187
Electronics
Prepared By:
Prangon Das
Assistant Professor, Department of Mechatronics Engineering,
Rajshahi University of Engineering & Technology.
9/4/2026
1
Fixed Bias Configuration
Fixed Bias Configuration
Fixed Bias Configuration
Fixed Bias Configuration
Emitter Bias Configuration
Emitter Bias Configuration
Emitter Bias Configuration
Emitter Bias Configuration
Voltage Divider Configuration
Problem with previous bias circuits:
ICQ and VCEQ were highly dependent on transistor current gain β.
Why β is a problem:
• β changes with temperature.
• Actual β value is often not well defined.
• This causes the Q-point to shift, making the amplifier unstable.
Solution: Voltage-Divider Bias
• Designed to make IC and VCE less dependent on β.
• Provides a stable operating point (Q-point).
Main advantage:
• Properly designed voltage-divider bias can make:
• ICQ and VCEQ
• almost independent of β.
Two analysis methods:
• Exact Method
• More accurate.
• Can be used for any voltage-divider bias circuit.
• Approximate Method
• Faster and simpler.
• Used when certain conditions are satisfied.
• Applicable in most practical cases.
Voltage Divider Configuration
Exact Analysis
Exact Analysis
Voltage Divider Configuration
Voltage Divider Configuration
Voltage Divider Configuration
Task: Approximate Analysis
Task: EXAMPLE 4.9, 4.10, 4.11
Collector Feedback Configuration
Collector Feedback Configuration
Collector Feedback Configuration
Task: EXAMPLE 4.13, 4.14
Common Collector Configuration
Common Collector Configuration
Common Base Configuration
The common-base configuration is unique in that the applied signal is connected to the emitter terminal and the base is at, or just above, ground
potential. It is a fairly popular configuration because in the ac domain it has a very low input impedance, high output impedance, and good gain
Common Base Configuration
Task: EXAMPLE 4.18, 4.19, 4.20
SUMMARY TABLE
Task: EXAMPLE 4.21, 4.22, 4.24, 4.25, 4.29, 4.30, 4.31 and Similar Problems from Exercise