Bad Fast Fourier Transfer (FFT) data captures can cause you to misunderstand the true performance of your high-speed or RF analog-to-digital converter (ADC). Some engineers like to coherently sample and capture data (which means to have the analog input frequency and clock frequency locked in phase with a reference frequency), while others do not necessarily need to. However, in either setup, there can be a need to refresh some details to present good data in your next design review.