1. High Current Gain:
- The common emitter amplifier provides the highest current gain (β) among the basic BJT configurations. This means a small base current can control a much larger collector current, enabling amplification of signals.
2. Moderate Voltage Gain:
- While not as high as the common base configuration, the common emitter offers a good balance between current and voltage gain, making it suitable for a wide range of applications.
3. Wide Bandwidth:
- The common emitter configuration has a wider bandwidth than other configurations, allowing it to amplify signals across a broader range of frequencies.
4. High Input Impedance:
- The input impedance of a common emitter amplifier is relatively high, making it less susceptible to loading effects from the signal source. This allows it to amplify signals without significantly affecting the signal source.
5. Moderate Output Impedance:
- The output impedance of a common emitter amplifier is moderate, allowing it to drive various loads without significant impedance mismatch.
6. Versatility:
- The common emitter configuration can be used in various amplifier applications, including:
- Small-signal amplifiers: Amplifying low-amplitude signals.
- Power amplifiers: Amplifying high-power signals.
- Audio amplifiers: Used in audio systems for amplifying sound signals.
- RF amplifiers: Used in radio frequency applications.
7. Ease of Implementation:
- The common emitter configuration is relatively straightforward to implement and can be easily integrated into circuits.
8. Wide Availability:
- Transistors designed for common emitter operation are readily available and are used in a wide range of electronic devices.
In summary: The common emitter configuration offers a good balance of gain, bandwidth, input/output impedance, and versatility, making it the most widely used amplifier configuration in various applications.