I have modeled ADC for 16 BIT and want to calculate Internal noise due to ADC.The ADC model description is given below:


ADC out = adc(input,freq,phase,OSR); % call ADC

inside adc function
[
KT/C noise (Integrators) random number generation
for i = 1 to OSR
   input ADC = input;
   ADC Integrators and compartor algorithm for MASH 1:1 with    noise coefficients
end

filter section
output of ADC
]

How shud i calculate the internal noise Vrms Vs Vin for ADC.What si the procedure? When i give the DC ramp input i get the noisy output code as attached in figure (zoomed). how to measure rms noise for Dc input voltage ramp ?

the figure 4 in this pdf (link )gives plot of internal noise of ADC Vs Vin(analog) but i am not getting idea how to achive it.How to find rms noise value.
http://www.ti.com/lit/an/slyt339/slyt339.pdf

http://www.analog.com/library/analogDialogue/archives/40-02/adc_noise.html

http://www.analog.com/library/analogDialogue/archives/29-2/cnvtrnoise.html

Now if i give just one value of DC input say input = 2V, after OSR =256 cycles , i get one output code.How can i get the rms noise?

or shall i do the sin histogram test and calculate FFT? i have already done that and discussed in link :
http://www.designers-guide.org/Forum/YaBB.pl?num=1325873498
and founf fft using sin input,calculated FFt result..calculated Noise power from that but it dont comes in microVolts (it comes 0.2099) for 2.8 V input amplitude
PS: DNL INL is not good becoz i took less points to plot.

Also be mindful that the reference noise plays a big role also.