Week 11
Common-Source Amplifiers
I organize a study path from diodes to single-transistor amplifiers in the order that makes the circuit behavior easiest to revisit.
What I connect in this unit
Transconductance and drain resistance set common-source small-signal gain, while source degeneration trades gain for bias stability and linearity. The quiescent point must leave headroom for drain voltage swing in both directions.
Concept map
- Small-signal gain
- Source degeneration
- Drain resistance
- Bias point and swing
Technical anchor
Without a source bypass, Av ≈ −gm(RD ∥ ro ∥ RL)/(1 + gmRS), and the nearest cutoff or triode boundary limits undistorted drain swing.
How I review it
Mark the quiescent point on the DC load line, multiply the expected input peak by gain, and verify that drain extrema stay within saturation and away from cutoff.
Connection to the full course
Unit 11 of 12. Unit numbers form a concept-study sequence and do not claim the original class schedule.