59.4.2. Input Resistance Calculation

Try these first

1. 1.

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

   Hint

   Remember to include both transconductance and output resistance.

2. 2.

   Define input resistance and its importance in an amplifier.

   Hint

   Think about how different resistances can affect input signal strength.

3. 3.

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

   • A_v = R_D / R_in
   • A_v = g_m * R_D
   • A_v = R_in * g_m

   Hint

   Focus on understanding the role of transconductance.

4. 4.

   True or False: Input resistance affects the signal strength that can be amplified.

   • True
   • False

   Hint

   Remember how resistance interacts with voltage and current.

5. 5.

   Design a multi-stage amplifier that uses a common source followed by a common drain stage. Specify component values and justify your choices based on expected voltage gain and input resistance.

   Hint

   Consider the required specifications for voltage gain and input resistance. Analyze each stage's contribution.

6. 6.

   In a given circuit, if the input resistance is found to be 100 kΩ and the desired conditions change causing it to increase by 50%, what is the new input resistance?

   Hint

   Simply calculate 50% of the current resistance and add it back.