Delta sigma d/a converter

摘要

In a delta sigma type D/A converter, in order to be capable of carrying out muting operation in steps at steps lower than 1 quantized step by digital processing, a multiplexor 2 for selectively outputting a mute code 15 for making an analog signal null and a thermometer code 14 to a local DAC4 is provided between a thermometer code converter 1 and the local DAC4, a time period of 1/M of a sampling period is made to constitute 1 cycle, at m1 (0≤m1≤M) cycle, the thermometer code 14 is made an output of the multiplexor 2 and at other m2 (m2=M-m1) cycle, the mute code 15 is made an output thereof and muting is carried out by reducing the ml cycle or muting is relieved by increasing thereof in steps at respective sampling period.