Introduction - If you have any usage issues, please Google them yourself
PLL is a feedback circuit, and its role is to make the clock circuit and a phase of external clock synchronization. PLL signal by comparing the external voltage-controlled crystal phase and the (VCXO) to achieve synchronization phase, in comparison, the phase-locked loop circuit will continue in accordance with external signals of local oscillator phase to adjust the clock phase, until Phase synchronization of two signals.