Sample & Hold ENOB Measurement problem(INPUT pulse).

[ljy4468]

Hi all
I've a question about SHA measure problem in simulation
I've heard that
to measure SHA's ENOB, FFT analysis is meaningless.
So we could give pulse input, then see output and anlyse how much
voltage deviates from input.

Is it right??
If so why FFT analysis is meaningless?

Please answer me in detail

Thanks in advance

 

[willyboy19]

Usually SHA is used in together with the following switched-capacitor circuitry for further processing ( a good example is pipelined ADC). Thus, FFT analysis is definitely useful if you pay attention to where and when to process the data. The pulse response is useful, but it does not provide full picture of the dynamic performance of the SHA.