A Class AB amplifier combines the efficiency of Class B amplifiers with the linearity of Class A amplifiers, achieving a balance between power efficiency and signal fidelity. It operates by biasing the transistors slightly above cutoff to minimize crossover distortion while maintaining better efficiency than purely Class A designs.

Class AB Amplifier

Class AB amplifier

efficiency of Class B amplifiers

linearity of Class A amplifiers

Power efficiency refers to the ratio of useful power output to the total power input, maximizing performance while minimizing energy waste. It is crucial in reducing operational costs and environmental impact across various technologies and systems.

power efficiency

Signal fidelity refers to the accuracy with which a transmitted signal replicates the original source signal, crucial for maintaining data integrity in communication systems. High signal fidelity ensures minimal distortion and noise, preserving the intended information across various transmission mediums.

signal fidelity

biasing the transistors

Crossover distortion is a type of distortion that occurs in class B and AB amplifiers when the output signal transitions between the positive and negative halves of the waveform, resulting in a non-linear region around the zero crossing point. This distortion is caused by the time delay and voltage drop required to turn on the transistors, leading to a loss of signal fidelity especially at low signal levels.

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