The document compares three common transistor configurations: common base (CB), common emitter (CE), and common collector (CC). It outlines the characteristics of each configuration, including their typical input and output impedances, current and voltage gains, phase inversion, and applications. A table summarizes the main parameters for each configuration, such as their voltage and current gains, power gains, phase inversion, and typical input and output impedances.

1. By
RAVICHANDER B
Assistant Professor ,Dept of ECE
Comparison of CB,CE and CC
configuration

2. Transistor CB (Common Base)
configuration
 It is transistor circuit in which base is kept common to the
input and output circuits.
Characteristics:
• It has low input impedance (on the order of 50 to 500
Ohms).
• It has high output impedance (on the order of 1 to 10
Mega Ohms).

3. Transistor CE (Common Emitter)
configuration
 It is transistor circuit in which emitter is kept common to
both input and output circuits.
Characteristics (applications):
• It has high input impedance (on the order of 500 to 5000
Ohms).
• It has low output impedance (on the order of 50 to 500
Kilo Ohms).
• Current gain (Beta) is 98.
• Power gain is upto 37 dB.
• Output is 180 degree out of phase.

4. Transistor CC (Common Collector)
configuration
 It is transistor circuit in which collector is kept common to both
input and output circuits. It is also called as emitter follower.
Characteristics:
• It has high input impedance (on the order of about 150 to 600
Kilo Ohms).
• It has low output impedance (on the order of about 100 to
1000 Ohms).
• Current gain (Beta) is about 99.
• Voltage and power gain is equal to or less than one.

5. Following table summarizes important points about CB,CE,CC
transistor configurations.
Parameter Common Base Common Emitter
Common
Collector
Voltage Gain High, Same as CE High Less than Unity
Current Gain Less than Unity High High
Power Gain Moderate High Moderate
Phase inversion No Yes No
Input Impedance Low (50 Ohm)
Moderate (1
KOhm)
High (300 KOhm)
Output Impedance High (1 M Ohm) Moderate (50 K) Low (300 Ohm)

6. Thank you