What is the pull in range of the HMC3716 digital phase freq detector? Is it limited to the 10-1300M? The issue is how accurate the initial VCO frequency needs to be. I will use a reference freq of 1000MHz. If the initial VCO freq error means the HMC3716 VCO input is > 1.3GHz, could the PLL fail because the PFD cannot steer the VCO tune voltage correclty?
I would prefer that, with the VCO input as high as 2GHz, the HMC3716 acts as a frequency discriminator, steering the loop in the right direction until the VCO input freq drops below 1300MHz, and the phase detector function can act properly.