I noticed that always the VCO tuning range is between 40 and 80 % of the nominal voltage.
What about VCOs in which the Tuning range is between 80 % and 90 % ?
I noticed that always the VCO tuning range is between 40 and 80 % of the nominal voltage.
What about VCOs in which the Tuning range is between 80 % and 90 % ?
It is up to the CP output voltage range.
When the Vtune larger than 80% or lower than 20%, CP will be mismatch.
But if you use ADPLL, there is no problem.
If the VCO could use only 10% of the supply as voltage tuning range it will be more sensitive to noise and tolerances. Typical designs try to maximize the range ro 20-80% which could be covered by either a chargepump or an opamp in an active loop filter.