Long, As I mentioned before, you must keep your fundamental power below -1dBFs or you will start saturating the ADC. Above, your fundamental is at 1.96dBFs. You need to back this off at least 3dBs. Once you get this all under control, I suggest you use an input frequency that is shown in the data sheet and compare your results with the data sheet. You should be able to get at least the typical values shown in the data sheet. If not, then one reason for this would be a noisy clock source. If this is the case, find a source with better phase noise performance and maybe use a filter for the clock input. Other issues could be a noisy analog input source and/or power supplies. I am guessing your main problem is your input power is to high. Regards, Jim
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