Source follower configuration has AVO (voltage gain) independent of the circuit elements.

Explanation:
- The source follower configuration, also known as the common drain configuration, is a type of amplifier configuration where the output voltage is taken from the source terminal of the transistor.
- In this configuration, the input is applied to the gate terminal, the output is taken from the source terminal, and the drain terminal is connected to a fixed potential such as ground.
- The voltage gain of an amplifier is defined as the ratio of the change in output voltage to the change in input voltage. It indicates how much the input signal is amplified by the amplifier.
- In the source follower configuration, the voltage gain (AVO) is close to unity or slightly less than unity.
- The reason for this is that the output voltage is approximately equal to the input voltage minus the threshold voltage of the transistor. This means that the output voltage does not vary significantly with changes in the input voltage.
- The voltage gain is independent of the circuit elements because it is primarily determined by the transistor itself and not by the external components.
- The transistor acts as a voltage buffer, where the input voltage is replicated at the output with minimal distortion or amplification.
- Since the output voltage closely follows the input voltage, the voltage gain is considered to be unity or close to unity.
- This configuration is commonly used in applications where a high input impedance and low output impedance are required, such as in impedance matching or signal buffering.
- In summary, the source follower configuration has AVO independent of the circuit elements because the voltage gain is primarily determined by the transistor characteristics and not by the external components.