I am trying to learn more about the Input Referred Noise test as applicable to a sigma delta ADC. I came across the application note for a ADC 7730. How can the test below be made more stable/accurate in the context of a production test for a sigma delta ADC? Can we add a digitial filter? What are the common causes of instability in an IRN test for a sigma delta ADC?
i. IRN test details:
A DC source is applied to the input of the Sigma-Delta ADC as a common-mode voltage bias. Then, the ADC captures 64K points & we post process the samples to determine IRN.