Question

High frequency response of CS amplifier has a Miller multiplier equal to

• A. 1+gmRL'
• B. -gmRL'
• C. 1/gmRL'
• D. 1/gm

Hint:

The Miller effect results in an effective capacitance at the input, and is a characteristic of amplifiers with feedback like common source configuration.

Answer 1

The Correct Option is A

In a Common Source (CS) amplifier, the Miller effect causes an effective increase in the input capacitance due to the feedback from output to input. The Miller multiplier is given by \(1 + g_mR_L'\), where \(g_m\) is the transconductance and \(R_L'\) is the effective load resistance. This multiplies the feedback capacitance and decreases the bandwidth of the amplifier.