DIGITAL-TO-ANALOG CONVERTING APPARATUS

摘要

The principal of the digital-to-analog converting system is such that N-bit input digital data is divided into at least nH higher order bits and nL lower order bits, the nH higher order bit data are converted to a PAM wave, the nL lower order bit data are converted to a PWM wave, and the PAM and PWM waves thus obtained are added in time relation to each other to obtain an analog output. The merrit of this invention is a higher resolution of D/A conversion combined with the advantage of a considerable reduction of the operation frequency of the PWM wave pulse width control counter to a practically realizable frequency range. The dynamic range is broad and distortion of the analog output signal is lower.