System for analog-digital-analog conversion

摘要

Control circuit, which is connected to a data processor, a D-A converter, such as a current integration type adaptive delta demodulator, and a data processing mode change command terminal, attenuates output from the data processor in response to a data processing mode change command from the data processing mode change command terminal while delaying the data processing mode change command by a first prescribed time to supply the command to the D-A converter and releasing the attenuation of the output of the data processor after a lapse of a second prescribed time which is longer than the first prescribed time. Thus, no instable output data from the data processor appear at the output of the D-A converter so that no noise is caused.