Design of a New Audio Signal Generation Circuit

This paper presents a new audio signal generation circuit using sine superposition to generate audio signal. Compared with the traditional circuit, the proposed audio signal waves are provided by a waveform conversion method. Besides, the independent envelope control is used, which greatly improves the system integration. The signal source is provided by an oscillator, and the amplitude is adjusted by variable gain amplifiers. The phase control is provided by the data selector, the subtraction circuit is used to reduce the DC level. Finally all the signals are superimposed to obtain the complete audio signal. The circuit design is based on SMIC 0.18pm CMOS technology, and the layout area is about 0.12mm
²
. The power supply voltage is 3.3V, and various audio signals can be created and testified in simulation.