measurement of sigma-delta ADC

[golohoyeah]

What is the basic requirement of equipment for measuring a 14-bit resolution of a sigma-delta ADC, in particular to measure the Signal
to Noise ratio ?

 

[samsuffy]

for a simple (DC) estimation of the SNR, a good 6-digit multimeter can be enough.
However, you will have to take care of the design of your test board (connector, decoupling , etc....) especially for sigma-delta ADC where digital output noise can easily affect analog input.

 

[golohoyeah]

hi Samsuffy, how to measure the SNR ratio value from a 6-digit multimeter ? please help.

 

[mc_navman]

Measuring Signal To Noise of a sigma delta

this needs to be done at the frequency of interest. Run the ADC at the required sample rate with no signal input and find the aplitude of the result, for example for a signed output take 8192 samples and find the RMS value. then do the same with the max undistorted signal on the input, and a S/N figure can be calcuated from the result (using 20*log(V1/V2) a much more complicated result might be required if you need a frequency response of the signal to noise as the noise figure will be different at different frequencys.

 

[eezou]

You can use logic analyzer to get data. The data is analysed by MATLAB program