Advantages and Disadvantages of transistor amplifier

Advantages of CE amplifier:

1. A common emitter amplifier is inverting and has low input impedance
2. high output impedance 
3. high voltage gain
4. high current gain.

Disadvantages of CE amplifier: 

1. 1. It has a high output resistance. 
2. 2. It responds poorly to high frequencies. 
3. 3. It has high thermal instabilities. 
4. 4. It's voltage gain is very unstable.

Advantages of CB amplifier:

1.  decent voltage amplifier, and current in is about equal to current out (actually current in is slightly greater than current out).
2. The common base circuit works best as a current buffer. It can take an input current at a low input impedance, and deliver nearly that same current to a higher impedance output.

Disadvantages of CB amplifier:

1. It requires two DC power sources to run this type of circuit.
2. Measure another voltage between emitter (input) and Collector(output). 
3. Compare voltage between Emitter and Base to see it is within the limit of transistor. 
4. Common Base circuit mostly use on OSC circuit or matching circuit. It has less gain than CE type.
5. amplification factor of common base amplifier is less less than common emitter amplifier.

Advantages of CC amplifier:

1. It has current gain but maintain voltage gain unchanged
2. It has the lowest output impedance compare to other type amplifier
3. It can be used for impedance matching between an amplifier stage with a high output impedance and an amplifier stage with a low input impedance.
4.  When used like this it is sometimes called a buffer amp or isolation amp. 
5. When placed between the the two stages it prevents the stage with the low input impedance from overloading the stage with the high output impedance.
6. The Voltage gain of a common collector amp is at best slightly less than 1

COMPARISON AMONG DIFFERENT TYPES OF AMPLIFIER:

	Common Emitter	Common Collector	Common Base
Voltage Gain	Medium	Low	High
Current Gain	Medium	High	Low
Input Impedance	Medium	High	Low
Output Impedance	Medium	Low	High