Diodes: AC Analysis of Small Signals

This type of analysis is a bit trivial with diodes but I’ll introduce the approach here before we put it to better use with transistors.

This is the opposite of large signal analysis. The input is small such that the diode does not transition between regions. We’ll focus on the forward-bias region for as that is the most exciting! Okay, my kind of exciting. Probably not your kind of exciting.

To analyze how a small signal will affect the output of a diode circuit we break the analysis into two distinct parts: 1) DC analysis and 2) AC analysis. This is effectively superposition but superposition worked before because everything was linear. The diode VI characteristic is nonlinear. How do we handle this?