68.1.3. Numerical Examples and Design Guidelines

Try these first

1. 1.

   What does the term 'active load' refer to in amplifier design?

   Hint

   Think about how passive components differ from active components.

2. 2.

   What is the typical value of Vt at room temperature?

   Hint

   This is a constant related to thermal voltage.

3. 3.

   What is the purpose of using an active load in amplifiers?

   • To decrease voltage gain
   • To enhance voltage gain
   • No effect on voltage gain

   Hint

   Think about the advantages active devices provide.

4. 4.

   True or False: The output voltage in an amplifier with active load can be assumed as the midpoint supply voltage under balanced conditions.

   • True
   • False

   Hint

   Consider how voltages split across equal resistances.

5. 5.

   Given a transistor amplifier with an active load arrangement where V_CC = 15V and R values are provided, derive the expressions for Ic, V_out, and small signal parameters if β = 120.

   Hint

   Break down the problem using Kirchhoff's laws to analyze the DC conditions.

6. 6.

   Assess how introducing a load capacitor impacts the cutoff frequency of a CE amplifier with an active load, considering all relevant parameters.

   Hint

   Use the RC time constant formula to evaluate the impact.