SNR of Incremental delta-sigma ADC

[electronics_rama]

Hi All,

I have developed the MATLAB model of incremental delta-sigma ADC. This model gives an output digital code corresponding to the input. It is working fine. This ADC model comes with its own quantization noise based on the OSR I have used. Higher the OSR, better will be the quantization noise. Now I want to analyze the SQNR performance of this ADC model in MATLAB. Can anyone help with suggestions on how can I proceed? Any references will be highly useful.


Thanks.

 

[electronics_rama]

Any help for the above question?

 

[nitishn5]

I am not sure of how appropriate this would be but here is my idea.
This is based on the simulation of ADCs to find their SNR/ENOB/etc.
Since in your model, there is no noise or non-linearity, we only have the quantization noise which all that should show up in the SNR., I.e. SNR=SQNR.

The test to run is a Sine Wave Test. You can look up sine wave testing of ADCs.

1. Give an ideal sine wave as an input to your ADC model
2. Take the output code and give it to an ideal DAC.
3. Take the output of the DAC and run a spectrum analysis on that. (FFT)

The output of the ideal DAC should be technically Ideal sine Wave with ADC noise added.
So the spectrum of that should give you the info on the SQNR and other related performance parameters.

The above testing is done for Nyquist ADCs such as SARs since the number of points to be converted is much less than in Sigma Delta and hence would not take "too much" time. A full simulation on a sigma delta might take for ever. But for a MATLAB simulation, it should not be a problem.