I have designed custom board based on AD9268 evaluation board which is recommended by ADI in which I am using four no. of AD9648 adc's and output is going to KINTEX-7 FPGA. I have started testing of adc's
.Input to adc is sine wave 60MHz and sampling clock is sine wave 50 MHz (under sampling). Both the clock sources are synchronous.My problem is I am getting SNR of 30dbfs where as data sheet says 74 dbfs at 70MHz, pls help me out in improving my SNR.