16.5. Amplification Analysis

Try these first

1. 1.

   Define 'common source amplifier' in a MOSFET circuit.

   Hint

   Think of the basic setup of the amplifier.

2. 2.

   What is the role of the threshold voltage (V_th) in MOSFET operation?

   Hint

   Consider what is needed to construct a conductive channel in the MOSFET.

3. 3.

   What is the main operational condition for a MOSFET to be in the saturation region?

   • V_DS > 0
   • V_DS > V_GS - V_th
   • V_GS < V_th

   Hint

   Relate it to the characteristics of operational modes.

4. 4.

   True or False: A MOSFET uses current to control output.

   • True
   • False

   Hint

   Think about the differences between MOSFETs and BJTs.

5. 5.

   Analyze a common source amplifier circuit where the input signal varies sinusoidally. Derive the corresponding output signal expression and explain how amplitude affects amplification.

   Hint

   Consider the feedback factors and load impedance.

6. 6.

   Given a circuit with an n-channel MOSFET, calculate the required gate voltage for the MOSFET to enter the saturation region given a load resistance and a specific supply voltage.

   Hint

   Focus on V_GS relative to V_DD and threshold conditions.