2.5.2. Superthreshold Operation

Try these first

1. 1.

   What does it mean when a transistor operates in superthreshold mode?

   Hint

   Think about the relationship between gate-source voltage and threshold voltage.

2. 2.

   What is the significance of the threshold voltage?

   Hint

   Consider the point at which the transistor switches from off to on.

3. 3.

   What two regions can a transistor operate in during superthreshold operation?

   • Cutoff and Linear
   • Linear and Saturation
   • Saturation and Cutoff

   Hint

   Remember what happens when the gate-source voltage is above the threshold voltage.

4. 4.

   True or False: A transistor in superthreshold operation has negligible current flow.

   • True
   • False

   Hint

   Think about the operational characteristics of the transistor at this voltage state.

5. 5.

   Design a simplified CMOS circuit that operates effectively in the superthreshold region and explain the reasoning behind its design choices.

   Hint

   Consider how the characteristics of NMOS and PMOS affect the inverter's performance.

6. 6.

   If you were to analyze the schematic of a common digital circuit, identify components that are likely operating in superthreshold. Justify your analysis based on expected operational voltages.

   Hint

   Think about the conditions under which digital components are driven to ensure high-speed operation.