33.3. Department of Electronics and Electrical Communication Engineering

Try these first

1. 1.

   What is the expression for voltage gain in a common source amplifier?

   Hint

   Consider both output resistor and transconductance.

2. 2.

   Define transconductance.

   Hint

   It's often symbolized as g_m.

3. 3.

   What is the formula for voltage gain in a common source amplifier?

   • A = R_D * g_m
   • A = -R_D * g_m
   • A = g_m / R_D

   Hint

   Remember the relationship between voltage gain and the output resistor.

4. 4.

   True or False: The input resistance of a common source amplifier is high due to zero gate current.

   • True
   • False

   Hint

   Think about what happens at the input port.

5. 5.

   Given a common source MOSFET amplifier with a transconductance g_m = 2 mA/V, find the output voltage for an input AC swing of 0.5V, given that R_D = 3 kΩ. Calculate the voltage gain and the expected output swing.

   Hint

   Use the gain formula learned earlier.

6. 6.

   Discuss how you would design a common source amplifier to optimize its voltage gain in an integrated circuit environment as compared to discrete circuit designs.

   Hint

   Think about the trade-offs in real estate versus performance.