sigma delta modulaotrs testing!!

[beargebinjie]

Hi guys:
i have designed a sigma delta moduator, and it has been tapped out. For it does not contain post digital filter, i plan to fulfilt it with FPGA. i am really green in this region, can anyone give me some useful suggestions.

 

[ustcjin]

Hi, for the test, I don't think you need a digital decimation filter.
You can capture your digital output codes by a logic analyzer and then perform FFT analysis.

 

[pfd001]

ustcjin is right. u can capture the data and use matlab to get the modulator performance

 

[ls000rhb]

if without decimation filter,just only simga-delta modulater ,can we derive the SNR?

 

[beargebinjie]

does only logic analyzer is enough? can we store the data in it wilthout anyother memory?

 

[gingerjiang]

i want to know whether SNRs are the same with digital filter or without digital filter?

 

[pfd001]

It depends on your filter performance. If your digtal filter is good enough, you will get nearly the same SNR

 

[beckchm]

just use software to test similarly

 

[beckchm]

It is just the same as software testing

 

[rfic]

use matlab software to test.

 

[xusoso]

ustcjin is right. u can capture the data and use matlab to get the modulator performance

in detail plz