CLASS D AUDIO AMPLIFIER OF USING DATA WEIGHTED AVERAGING ALGORITHM

摘要

A class D audio amplifier using a data weighted averaging algorithm is provided to suppress power consumption due to the generation of a ripple current by reducing the voltage difference between both ends of a speaker to the maximum VDD level in the same time interval. A class D amplifier includes a 3 level delta-sigma modulator(200), an output stage(220), a data weighted averaging unit(240), and a 3 level DAC(260). The 3 level delta-sigma modulator includes a 1.5 bit quantizer. The 1.5 bit quantizer outputs the output of an integrator or adder to the three kinds of digital signals. The output stage generates three kinds of output signals in both ends of the speaker according to the three kinds of digital signals. The data weighted averaging unit performs the data weighted averaging algorithm by using three kinds of output signals as a thermometer code. The 3-level DAC(Digital to Analog Converter) converts the digital signal to an analog signal according to the control of the data weighted averaging unit.