基于900MHz低压LVPECL时钟合成器的电路设计

字数:5500,页数:16

摘要：简要介绍900MHz低压LVPECL时钟合成器中主要芯片MPC9239的功能、内部结构、引脚排列及典型的应用电路。MPC9239主要由以下部分组成。一个PLL锁相环电路，三个锁存器，和一个12位移位寄存器及若干分频器组成。题目中的LVPECL即低压正射极耦合逻辑。
关键字：晶体振荡器 锁相环PLL 串联与并联

Abstract
It briefly introduced The microcontroller function, internal structure, pin array and typical apply circuit of the MPC9239 about the MHz Low Voltage LVPECL Clock Synthesizer. The MPC9239 is taken up of some parts below. A crystal oscillator, three latches and a 12bits shift register. The LVPECL is low voltage positive emitter-coupled logic.
Key word:  crystal oscillator   phase-locked loop
           the serial and parallel
目 录

1. MPC9239芯片简介.....................................................................4
2. MPC9239芯片封装与引脚功能...........................................................4
   2.1 芯片封装........................................................................4
   2.2 引脚功能........................................................................5
3. MPC9239内部结构与工作原理...........................................................6
3.1 MPC9239 内部结构...................................................................6
3．1.1内部结构图.......................................................................6
3．1.2 使用板上晶体振荡器..............................................................6
3.2 MPC9239 工作原理...................................................................7
3.2.1 工作原理.........................................................................7
3.2.2 使用检测和诊断输出TEST...........................................................8
3.2.3 MPC9239的频率工作范围............................................................9
3.2.4 AC特性与DC特性...................................................................11
3.2.5 功能表...........................................................................12
3.2.6 通用说明书.......................................................................12
3.2.7 绝对最大值测定...................................................................13
4. MPC9239应用电路设计.................................................................13
4．1  布局推荐.........................................................................13
4．2  电源滤波.........................................................................14
4．3  MPC9239编程......................................................................15
4．4  运用内部串联与并联...............................................................16
5. 总结................................................................................16
参考文献...............................................................................16