Class AB push-pull(Circuit same as Class A push-pull)
Class AB is a compromise between class A and class B .Class B amplifiers are highly efficient but their output waveform is distorted due to cross over,This occur in class B because of the absence of current at zero crossing point of input signal .This limitation can be overcome by biasing the transistor just at cut in (0.7V for Si).This resulting configuration is Class AB. To reduce harmonic distortion also class A is used the value of \(R_2\) is chosen in such a way that only 0.7v is allowed to drop across \(R_2\) .Performance of class AB is between class A and class B ,less efficient than class B and more than class A(0.5 & 0.785) .Distortion in Class AB is less than class BMathJax example
Class AB is a compromise between class A and class B .Class B amplifiers are highly efficient but their output waveform is distorted due to cross over,This occur in class B because of the absence of current at zero crossing point of input signal .This limitation can be overcome by biasing the transistor just at cut in (0.7V for Si).This resulting configuration is Class AB. To reduce harmonic distortion also class A is used the value of \(R_2\) is chosen in such a way that only 0.7v is allowed to drop across \(R_2\) .Performance of class AB is between class A and class B ,less efficient than class B and more than class A(0.5 & 0.785) .Distortion in Class AB is less than class B
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