Amplifiers Summary#

At-a-glance comparison#

Property

Common source

CS w/ degeneration

Common drain

Common gate

Cascode

Gain

High

Medium

Low

Medium

Highest

\(R_{\text{in}}\)

\(\infty\)

\(\infty\)

\(\infty\)

Low

\(\infty\)

\(R_{\text{out}}\)

Medium

High

Low

Medium (high if \(R_s=0\))

High

Application

General amplifier

High-speed op amp

Buffer

Impedance matching amplifier

High-precision closed-loop op amp

Detailed comparison#