The Silicon Creations Fractional-N PLL (block diagram shown in Figure 2) suppresses this noise with the addition a feed-forward compensator that feeds directly into the loop filter, and is able to ...

Integer PLL Block Diagram. The PD output is filtered, and the filter drives a voltage-controlled oscillator (VCO). Loop dynamics are controlled by the filter characteristics.

Analog PLL block malfunction causes loss of lock, PLL sub-system input reference clock failure because of crystal break-down or pad failure, Ageing of the crystal causes changes in the input frequency ...