sigma delta adc 连续时间 DAC 比较器

a1054958688

求问continuous time sigma delta adc中的excess loop delay为何总是考虑dac的delay而不是考虑quantizer的delay（比如comparator）？

a1054958688

the important quantity in a ct sigma delta modulator is the “loop delay”，which we define as the total delay between the sampling clock edge and the edge of the DAC output。the quqntizer delay and the DAC delay are often represented by a single delay block，and the combination of these two delays is often referred to as the sigma delta modulator 's excess loop delay.