we are using ADC12D1800CIUT/NOPB; non RF part in one of the boards and are facing SFDR issue with the Fs/2 spur component in the captured data. Fs/2 component is prominent at -58dBm on all the boards. We have previous version boards which are using RF part and giving the better SFDR (better than 62dBFS). I want to understand what could be the possible reasons for this problem. Please help!
We are capturing the 160MHz input signal at 500MSPS and spike is seen at 250MHz which is Fs/2. Attached the capture of the ADC with no signal input.