一种快速锁定锁相环的方案设计

A design of a fast lock-in phase lock loop

提出了一种锁相环快速锁定的方案,在传统锁相环基础上,额外设置辅助充电模块,此模块可实现在输入参考时钟与反馈时钟频率差距较大时,提供大电流对滤波器中的电容充电,在临近锁定状态时退出快速锁定模式切断充电通路,因此极大地缩短了的锁定时间,并基于电路仿真验证了方案的可行性与稳定性。

In this paper,a fast lock-in scheme of PLL is proposed.On the basis of traditional PLL,an auxiliary charging module is added.This module can charge the capacitor of the filter with a large current when there is an obvious difference between the frequency of input reference clock and feedback clock,and quit the fast lock-in mode and cut-off the charging path when the frequency gap becomes small,which greatly shortens the lock-in time.The feasibility and stability of the approach are verified by circuit simulation.