Table of Contents
1. Classes
1.1. Class A
It is one biased transistor. Which allows large idle current, making it inefficient.
1.2. Class B
It combines NPN and PNP transistors, so that it can trigger regardless of the sign of the signal.
It suffers from zero-crossing distortion, due to the threshold volatage for each transistors.
1.3. Class AB
Class B, but the signal is biased slightly to remove the distortion.
1.4. Class D
It compares the analog signal with the steady triangular wave, and outputs according to the result of the comparison.