I am planning to use Hittite HMC506LP4 and ADI ADF4108 to generate an 8.0 GHz LO signal, -40...+85C.
In my prototype, Vtune settles to 2.7 V in the lock state, which is comfortably within the range that ADF4108 CP output can drive. How large margin for Vtune I should reserve for process variations in HMC506LP4? In addition to the temperature, the value of Vtune for the 8.0 GHz output frequency will vary from batch to batch. The temperature dependence is easy to handle based on the information on the HMC506LP4 data sheet. However, no information about the batch-to-batch variation is given. For wider margin, it is possible to boost the drive voltage with an active loop filter using an opamp, but I would not like to put in an extra IC, as my layout space is already quite limited.