[sdiy] Sigma Delta DSP

[mark verbos]

You will still need a lopass on the input if you don't want aliasing. 
Other wise frequencies that are higher than half the sample rate will 
cause you problems when only one half of their wave is sampled. A lopass 
on the output also wouldn't hurt to get rid of the stairsteps in the 
signal.

I don't see how this would be eliminated here. There is still a clock 
and discrete samples triggered by it. That means the above problems 
would manifast just like in any other A-D/D-A conversion.

Mark





wayfar wrote:
> 
>> At 05:45 PM 3/1/2006 +0100, Dave Krooshof - dendriet.nl wrote:
>>
>>> Hi List,
>>>
>>> I was wondering weather anyone here has knowledge about
>>> sigma delta processing. We allready bought a AD convertor,
>>> and we are interested in using the bitstream output directly.
>>> Converting back to analog is nothing more then a low pass, so
>>> that is easy.
>>
>>
> 
> I thought one of the major arguments *for* using that format over PCM 
> was in that you *don't* need a lowpass, the format it self somewhat 
> provides anti-aliasing.
> 
> 
>