quantizaiton noise help pleaaaaase

[arunkumar446]

hi all, how can we see quantization noise of a traditional ADC in matlab/simulink, just like the way shown in the document "Demystifying Sigma-Delta ADCs" by maxim, it's urgent, please reply asap.
Thanks in advance.

 

[philwinder]

I suppose the simplest way to do it is to generate a signal, then assign each element to its nearest quantising value, then just plot the different between the actual and the quantised signal.

I.e.

function [data] = quantise_round( datain, reference )
for x = 1:length(data)
temp = (datain[x] / reference) * 2^8;
fraction = temp - floor(temp);
if( fraction < 0.5 )
data[x] = floor(temp);
else
data[x] = floor(temp) + 1;
end
end
end

Well, something like that anyway (Disclaimer, not sure this will work!! - Hopefully you get the idea)

Phil