27.5. Solutions to Gain Issues

Try these first

1. 1.

   What is the purpose of the emitter resistor in a common emitter amplifier?

   Hint

   Think about the stability of the circuit when parameters change.

2. 2.

   How does adding a coupling capacitor help with gain?

   Hint

   Consider how AC and DC signals interact with circuit components.

3. 3.

   What happens to the voltage gain when an emitter resistor is added to the amplifier?

   • It increases
   • It decreases
   • It remains constant

   Hint

   Think about how the presence of feedback components influences gain.

4. 4.

   True or False: The introduction of a coupling capacitor can affect the DC operating point of the amplifier.

   • True
   • False

   Hint

   Consider the roles of AC and DC signals.

5. 5.

   Design a common emitter amplifier that maintains a voltage gain of at least 50 while keeping R_E to a minimum. Specify component values and justification.

   Hint

   Use A = -g_m × R_C / (1 + g_m × R_E) and ensure stability.

6. 6.

   How does a high β transistor affect the design of the common emitter amplifier? Provide a theoretical analysis and potential solutions.

   Hint

   Consider how β influences gain calculations and stability factors.