Bipolar Transistor Construction
- 1. Common Base Configuration - has Voltage Gain but no Current Gain.
- 2 Common Emitter Configuration - has both Current and Voltage Gain.
- 3. Common Collector Configuration - has Current Gain but no Voltage Gain.
The Common Base Configuration.
The Common Base circuit is generally only used in single stage amplifier circuits such as microphone pre-amplifier or RF radio amplifiers due to its very good high frequency response.
The Common Emitter Configuration.
Then to summarise, this type of bipolar transistor configuration has a greater input impedance, Current and Power gain than that of the common Base configuration but its Voltage gain is much lower. The common emitter is an inverting amplifier circuit resulting in the output signal being 180o out of phase with the input voltage signal.