30.3.1. Design Considerations

Try these first

1. 1.

   What is the function of a coupling capacitor in a common emitter amplifier?

   Hint

   Think about DC and AC signal interactions.

2. 2.

   Define quiescent point.

   Hint

   Consider what happens when signals are not applied.

3. 3.

   What parameter directly influences the voltage gain of a common emitter amplifier?

   • Supply Voltage
   • Transconductance (gm)
   • Emitter Current

   Hint

   Consider which values are multiplied to obtain gain.

4. 4.

   True or False: The quiescent point should be set to maximize output swing.

   • True
   • False

   Hint

   Think about balance in the output range.

5. 5.

   Design a common emitter amplifier for a small audio application targeting a gain of 40. Given a power supply of 10V and a maximum power dissipation of 20mW, outline the steps to choose appropriate resistor values.

   Hint

   Remember that understanding gain and power dissipation involves balancing act between V, I, and RC.

6. 6.

   You need to design an amplifier circuit that uses a silicon BJT with β = 150. Calculate the necessary parameters if you want a quiescent current of 1mA, and discuss how the output swing will be affected by your choices.

   Hint

   Think about how the quiescent current and beta affect the biasing network.