There always exists the possibility that the VCO is not able to follow the rapidly changing phase of the input, because the rate of change of the VCO phase is insufficient.
But it is always possible that the rate of change of the VCO phase is insufficient. There always exists the possibility that the VCO is not able to follow the rapidly changing phase of the input.
There always exists the possibility that the VCO is not able to follow the rapidly changing phase of the input. But it is always possible that the rate of change of the VCO phase is insufficient.
There always exists the possibility that the VCO is not able to follow the rapidly changing phase of the input. But it is always possible that the rate of change of the VCO phase is insufficient.