数字控制文氏桥振荡器设计

电子信息工程论文编号:DZXX138  论文字数:10971,页数:29

目录

摘要 I
ABSTRACT II
第1章 引言 1
  1.1 背景 1
  1.2研究内容 2
第2章 文氏桥振荡电路 4
  2.1文氏桥振荡电路概述 4
    2.1.1文氏桥振荡器的工作原理 4
  2.2 文氏桥振荡器的组成电路 6
    2.2.1 用晶体三极管组成的RC振荡电路 6
    2.2.2 用结型场效应管组成的RC振荡电路 7
    2.2.3 用集成电路组成的RC振荡电路 7
第3章 数字控制文氏桥振荡器设计 8
  3.1数字电位器的特点及运用 8
  3.2数字电位器X9511W的介绍 8
    3.2.1 芯片功能 8
    3.2.2 管脚功能 9
    3.2.3 工作参数 11
    3.2.4 数字电位器X9511W的应用 11
  3.3 数字控制文氏桥振荡器设计方案 12
  3.4 数字控制文氏桥振荡器的主要功能和要求 17
第4章 数字控制文氏桥振荡器的仿真分析 18
  4.1 仿真软件介绍 18
    4.1.1 直观友好的图形界面 18
    4.1.2 超强的仿真能力 18
    4.1.3 电路分析手段完备 18
    4.1.4 提供多种输入输出接口 18
  4.2 标准文氏桥振荡电路的仿真 19
第5章 结束语 22
致谢 23
参考文献 24
附录 原理图 25

摘要

 文氏桥振荡电路是一种能将直流能源转换成具有一定频率和幅度以及一定波形的交流能量输出的电路。数字式文氏桥具有调频灵活、覆盖范围宽、功能强等特点，因而在通信、无线电、自动控制等许多领域有着广泛的应用。
 本课题通过分析文氏桥振荡电路特性，提出了数字式调频的方案。选用X9511W数字电位器取代调频支路电位器，通过调节该数字电位器阻值改变输出信号频率，同时为了满足起振条件，负反馈热敏电阻也用该电位器取代。
 课题进行了原理仿真和电路调试，理论上能够满足文氏桥振荡器的调频特性，但是受所选用数字电位器阻值调节分辨率限制，振荡输出信号调频分辨率不高，同时信号易振荡也是这个原因。

关键词：文氏桥振荡器；数字电位器； X9511W；调频

ABSTRACT
 Wien's bridge oscillator circuit is a kind of energy which can be converted to DC with a certain frequency and amplitude, as well as the exchange of a certain energy output waveform of the circuit. Digital Wien's bridge has the flexible FM, wide output frequency scale, and powerful features, so it has a wide range of applications, such as  communications, radio, automatic control, and also many other fields.
 This issue analyzed the Wien's bridge oscillator circuit characteristics, and also proposed a digital FM method. In this design, X9511W was chosen to replace the potentiometers in the FM circuit. By adjusting the resistance of the digital potentiometer to change the output frequency. At the same time, to meet the start-up conditions, the potentiometer was also used to replace the thermistor which in negative feedback network.
 This issue carried out the principle of circuit emulation and debug. Theoretically, it was able to meet the characteristics of Wien 's bridge FM oscillator. However, the digital potentiometer resistance adjustment resolution was limited, the oscillatior output frequency was not precise, and the signal was ringing easily.
Keywords: Wien's bridge oscillator； Digital Potentiometers；X9511W；Frequency Modulation