Question

Which of the following statements is true about the small signal voltage gain of MOSFET-based single-stage amplifiers?

• A. Common source and common gate amplifiers are based on inverting amplifiers.
• B. Common source and common gate amplifiers are both non-inverting amplifiers.
• C. Common source amplifier is non-inverting and gate amplifier is inverting.
• D. Common source amplifier is inverting and common gate is non-inverting amplifier.

Hint:

For small signal analysis of MOSFET amplifiers, remember:
- Common Source: Inverting amplifier with high gain.
- Common Gate: Also an inverting amplifier with moderate gain.

Answer 1

The Correct Option is A

In a MOSFET-based amplifier circuit, the voltage gain of the amplifier depends on the type of configuration used. In this case, we are looking at common source and common gate amplifiers.
- Common Source Amplifier: This is an inverting amplifier configuration. The output voltage is inverted relative to the input voltage. The voltage gain for a common-source amplifier is typically negative, indicating inversion. 
- Common Gate Amplifier: This configuration is also an inverting amplifier. The input signal is applied to the gate, and the output is taken from the drain. Similar to the common-source amplifier, the common-gate amplifier produces an inverted output. 

Thus, the correct answer is (A) because both common source and common gate amplifiers are inverting amplifiers.