6.4.3. Voltage-Controlled Resistors

Try these first

1. 1.

   What is a voltage-controlled resistor?

   Hint

   Think about how it might be used in audio applications.

2. 2.

   What region of operation do MOSFETs work in to act as voltage-controlled resistors?

   Hint

   Consider the name of the region where MOSFET can adjust resistance.

3. 3.

   What is the primary function of a MOSFET operating as a voltage-controlled resistor?

   • To switch high currents
   • To adjust resistance based on voltage
   • To store data

   Hint

   Think about how it is used in circuit applications.

4. 4.

   True or False: The resistance in a voltage-controlled resistor increases with an increase in gate voltage.

   • True
   • False

   Hint

   Consider the operation principle of the MOSFET in the triode region.

5. 5.

   Design a variable gain amplifier circuit using a voltage-controlled resistor. Explain your design rationale.

   Hint

   Consider how feedback affects the gain to keep it steady.

6. 6.

   Evaluate the effects of varying the gate voltage on an audio circuit's performance when using a voltage-controlled resistor.

   Hint

   Think about frequency response in audio engineering.