Complementary metal oxide semiconductor class AB amplifier

The present invention relates to a kind of complementary metal oxide semiconductor class AB amplifier that includes an adaptive level shift circuit, a compensation capacitor and an output transistor pair. The adaptive level shift circuit is composed of a current mirror circuit, a diode transistor, a switch transistor, and a current source transistor. The diode transistor is connected in series to have bias for driving the switch transistor so as to provide a low linear region resistor for feedback. As a result, the Q value (quality factor) of convolution inductor can be reduced, and the occurrence of peak gain is effectively suppressed so as to maintain the required boundary gain.