27.5.2. Practical Design Guidelines

Try these first

1. 1.

   What does the emitter resistor R_E do in a common emitter amplifier?

   Hint

   Think about what happens to our circuit under changing conditions.

2. 2.

   How is the voltage gain A affected by increasing R_E?

   Hint

   Recall the gain formula.

3. 3.

   Increasing the emitter resistor R_E typically results in what effect on voltage gain A?

   • Increases A
   • Decreases A
   • No effect

   Hint

   Think about how R_E plays a role in the gain equation.

4. 4.

   True or False: The larger the emitter resistor R_E, the more sensitive the amplifier becomes to beta variations.

   • True
   • False

   Hint

   Remember the role of R_E.

5. 5.

   Design a common-emitter amplifier that satisfies a voltage gain of -10 while ensuring that it remains stable. Assume β = 100.

   Hint

   Calculate g_m and ensure all component interactions are balanced.

6. 6.

   Discuss the implications of lowering R_E to improve gain while keeping the same operational point and how it impacts low-frequency response.

   Hint

   Maintain focus on RC time constants while discussing this effect.