The ML2308 is a stereo recording/playback LSI that has integrated in a single chip all the functions required for recording and playing back audio data. Analog signals fed into the microphone or line inputs are converted into digital signals by the analog to digital converter, and output to external equipment via the buffer memory. Further, digital signals from external equipment are converted into PWM signals by the 1-bit digital to analog converter, and output by the PWM driver that can directly drive the headphones. The influence of noise is lower with the ML2308 when compared with the mixed analog LSI, since most of the signals are digitally processed inside the LSI.