Noise prevention in D/A or A/D conversion with two stage stepped gain control by using zero crossing detector to time gain changes

摘要

In an A/D converter which has stepped gain control on both the input and output side a zero crossing detector is used to determine the timing of gain changes so that they happen for both sides at a time of low signal. Thus switching noise is reduced. Fig. 13 shows a D/A converter with gain on the analog side controlled by a zero crossing detector on the digital side.