请教——一个小小的疑问

看了一些delta-sigma的资料，讲了很多的噪声问题，始终不理解：
为何不讲讲如何得到二进制编码的过程呢?
为何从delta-sigma调制器输出的信号经过滤波就可以实现A/D转换?
从脉冲宽度调制的信号变成具体的2进制编码，这过程到底发生了啥?
很是苦恼！
希望大家指点指点啊！

Use decimation filter to demodulate the PWM signal.It's just downsample and lowpass/bandpass filter. It has very narrow transition band to filter out high frequency noise.
It's digital sinc filter, so analog guys seldomly talk about this.
Maybe your DSP courses have already talk about digital filters. Check it.

只是在数字域做一个低通滤波器而已