Category: Hardware
Product Number: AD9697
I plan to sample 290-380M using AD9695-625 ADC with a 400M input clock. The decimation rate is 8, so so the JESD output rate is 2Gbps. I will use the NCO freq to tune within290-380M; the instantaneous bandwidth is < 5MHz.
1) Simulating with the VIRTUAL Eval tool - BETA, I see no apparent drop off with RF input from 290-390M. Is this real? Because I would sinx/x (SINC) effects to have an impact.
2) The FFT output is -7dBFS for a -1dBFS input setting. Why the 6dB loss? Is the simulation assuming such a loss in input matching ??
3) Screen shot below shows RF =393M (out-of-band) causing a spur -22M. Since 0Hz maps to NCO freq =379M, the main tone = (RF in -NCO) = 393-379 = 14M. -22M spur is equivalent to 379-22= 357M. What causing this ??
