文章在常用的几种数字PFD的性能缺陷分析基础上,通过对原有鉴频鉴相器的电路结构进行重新设计,提出了一种新型的无“过充”的预充式边沿触发的鉴频鉴相器,该电路可以实现鉴相性能无“死区”,具有优良的鉴频鉴相线性度和较高的鉴频鉴相灵敏度,电路结构相对简单。电路设计基于1^#SILICON 2.5V 0.25μmCMOS工艺。用Hspice对电路进行仿真,结果显示电路可以工作在1GHz以上频率的应用环境下。相比已有的几种常用鉴频鉴相器,该电路综合性能优越。
In this paper, on the basis of the analysis of the defects of several typical digital PFDs, with the reform of architecture of.them, a novel edge-triggered precharged PFD is proposed, which is designed to prevent it's output signal's period is excessive. The novel PFD's phase characteristic has no "dead zone", and it is of high phase and frequency sensitivity, good linearization; what's more, its structure is simpler. The design is based on 1^# SILICON 2.5V 0.2.Sum technology. Simulation results of the circuit with HSPICE show a better performance, even if it operates at 1GHz. In brief, the novel PFD has better overall performance compared with the typical PFDs.