AB amplifiers

Amongst class A, B, C, D, AB class AB amplifiers are conventionally used as loudspeaker in audio systems because they are enough efficient to be able to drive the required maximum output power, often on the order of 100 watt or more, without dissipating excessive heat, but can be biased to have acceptable distortion. Audio signals tend to be near zero most of the time, so good performance near zero output current is critical, and that is where class A amplifiers waste power and class B amplifiers suffer zero-crossing distortion. A class AB push-pull amplifier is also conventionally used as the output stage of a commercial operational amplifier. But designing a push-pull amplifier is the key task.