The Performance of a Digital Phase-Locked Loop with a Zero-Crossing Detector

使用过 零 检测器的数字锁相环的性能

Ased on the zero-crossing theory a new kind of edge detector with orientation selectivity and variable scale is presented and its discrete B spline form under a small scale is also given .

根据 过 零 交叉的视觉机理，提出了一种具有方向选择性和变尺度的特征 检测 算子，并以B样条形式给出了其小尺度下的离散化图象处理形式。

This paper discusses an all digital phase-locked loop with a zero-crossing detector and a loop filter .

本文讨论的全数字锁相环包括过 零 检测器和环路滤波器。

As a zero-crossing detector LoG operator is sensitive to gray scale variation is not easy to be interfered by non-uniform light field and can detect second order zero-crossing point that can accurately reflect local gray scale variation .

LoG算子作为一种 零 交叉 检测器对局部灰度变化敏感，不易受非均匀光场的干扰，可检测出能较准确反映局部灰度变化的二阶过零点。

A Directional and Scale-Variable Zero-Crossing Edge Detector

具有方向性、变尺度的 过 零 交叉特征 检测算子

To meet the high speed requirement a dynamic zero-crossing detector and current source to realize a precision charge transfer . It has a simple structure high speed small area .

针对高速的要求，采用了基于 过 零 检测器的开关电容电路来实现采样 保持功能，具有结构简单、速度快、面积小等优点。

The zero-crossing PLL i.e.hardware PLL is comprised of PFD ( Phase-Frequency Detector ) loop filter VCO ( Voltage Control Oscillator ) and frequency divider . It is really simple but poor in dynamic performance and even worse in phase lock effect with distorted input voltage .

过 零锁相即硬件锁相（PLL）由鉴相 器、环路滤波器、压控振荡器及分频器组成，其原理和结构较简单，但动态性能较差，且在畸变电压输入时锁相效果变差；