We are using AD9874 IF Digitizing chip for down conversion.
We are using discrete VCO for generation of LO of frequency 41.85MHz, to the LO input (LOP) of the AD09874.
When connected the Buffer Amplifier (SGA2463Z) between VCO output and LO input, observed that it is loading the VCO and its frequency is drifting by about 2 MHz.
Please let us know what is the recommended buffer amplifier?
What is the input impedance of LO input for the AD98974?