2.2. Basic Operation of NMOS and PMOS Transistors

Try these first

1. 1.

   What is the threshold voltage of a transistor?

   Hint

   Look for the term that describes the minimum gate voltage.

2. 2.

   What type of MOSFET conducts when a positive voltage is applied?

   Hint

   Remember the type of transistor that operates with positive gate-source voltage.

3. 3.

   Which type of transistor operates with a positive gate-source voltage?

   • NMOS
   • PMOS
   • Both

   Hint

   Recall which transistor needs a positive voltage to turn on.

4. 4.

   True or False: PMOS transistors turn on when VGS is above the threshold voltage.

   • True
   • False

   Hint

   Think about the voltage conditions necessary for PMOS to conduct.

5. 5.

   Design a simple CMOS inverter using one NMOS and one PMOS transistor. Explain how the circuit operates when the input is high and low.

   Hint

   Think about the complementary operation of the NMOS and PMOS circuits.

6. 6.

   Calculate the output current for a PMOS transistor under various VSG conditions based on the characteristics provided in the description.

   Hint

   Keep track of how VSG relates to the Vth described for PMOS.