32.1.2. Today's Module Plan

Try these first

1. 1.

   What does a Common Source Amplifier primarily amplify?

   Hint

   Think about the type of input and also how output is defined.

2. 2.

   What is the ideal gate current in a MOSFET for a Common Source Amplifier?

   Hint

   Consider the characteristics of a MOSFET.

3. 3.

   What type of amplifier is a Common Source Amplifier mostly considered?

   • Current Amplifier
   • Voltage Amplifier
   • Power Amplifier

   Hint

   Think about the primary input and output characteristics.

4. 4.

   True or False: The gate current of a MOSFET in a Common Source Amplifier is ideally non-zero.

   • True
   • False

   Hint

   Consider the operating principles of MOSFETs.

5. 5.

   A Common Source Amplifier has a threshold voltage of 1.5V and operates with a gate voltage of 3V. Calculate the required output voltage to keep the amplifier in saturation if the drain-source resistance is 500 ohms and you have an input signal of 0.1V.

   Hint

   Use Ohm's law to relate the output voltage to the current flowing through the drain-source resistance.

6. 6.

   Design a biasing circuit for a Common Source Amplifier where the desired DC gate voltage is 5V and the output should provide a gain of 10. What values for the resistors would you need?

   Hint

   Remember to apply the voltage divider concept along with the amplifier gain formula.