Conversion accuracy improvement of analog / digital and digital / analog conversion system

摘要

The system for improving the conversion accuracy of small input analog signal comprises an input circuit (10) receiving the voice signal to be converted to a first analog signal, an encoder (20) amplifying the analog signal of which level is lower than a certain value from the first analog signal and converting to a second analog signal, an A/D converter (30) providing a first digital signal converted from the second analog signal, a digital signal processor (40) converting the first digital signal to a second one, a D/A converter (50) converting the second digital signal to a third analog of signal, a decoder (60) depressing the analog signal which level is lower than a certain level from the third analog signal and converting to a fourth analog signal, and an output circuit providing the reproduced voice signal.