Dear Apurbaranjan Panda

in order to plot the INL/DNL of the ADC, you need to provide it with an input ramp. Chose the slope of the ramp low enough so that each output code happens at least 4 times. This gives you the output INL/DNL with the resolution of LSB/4. if you need better resolution you can always decrease the slope with the cost of longer simulations durations.

Dear Nima Shahpari

Thanks for your reply.

I have a concern about this. Please take the difficulty to clear my doubt about how can I find INL/DNL with digital code. As we know, ADC gives code only at its output.

Or.

I need to reconstruct the signal from the digital code to find the INL/DNL. If the latter is true, then I need an ideal DAC to rebuild.

Then another concern is how can I test the ADC during measurement.

Thanking you.

Dear Apurbaranjan Panda

You are absolutely right and for ADC verification you need to also have an Ideal DAC to convert the code to discrete voltage levels.