I have a confusing problem with ADA4938-2. I connected ADA with unity gain and dual supply to AD9253. Vocm is provided by ADC. Schematic and parts values seem to be correct but output of ADA is very noisy. Any suggestion??
Both FFTs are noise floor of ADC. First with op amp and second without it. I really confused about this. I've designed many software radio cards including ADC, DAC, FPGA and ... and this circuit is first of them that failed in analog section.