I am currently using your PLL ADF4159 and I have a question which is not directly answered by the datasheet: My VCO provides a differential and prescaled RF signal, which has to be terminated with an impedance of 100 Ohms. On page 11 of the ADF4159 datasheet, I can find a drawing of the RF input stage (Fig. 19), but there is no comment about the input impedance. It looks like the PLL’s RFin is High-Z, so I have to terminate my RF signal externally. Can you confirm this?
Thank you for your answer!