數字控制文氏橋振蕩器設計

電子信息工程論文編號:DZXX138  論文字數:10971,頁數:29

目錄

摘要 I
ABSTRACT II
第1章 引言 1
  1.1 背景 1
  1.2研究內容 2
第2章 文氏橋振蕩電路 4
  2.1文氏橋振蕩電路概述 4
    2.1.1文氏橋振蕩器的工作原理 4
  2.2 文氏橋振蕩器的組成電路 6
    2.2.1 用晶體三極管組成的RC振蕩電路 6
    2.2.2 用結型場效應管組成的RC振蕩電路 7
    2.2.3 用集成電路組成的RC振蕩電路 7
第3章 數字控制文氏橋振蕩器設計 8
  3.1數字電位器的特點及運用 8
  3.2數字電位器X9511W的介紹 8
    3.2.1 芯片功能 8
    3.2.2 管腳功能 9
    3.2.3 工作參數 11
    3.2.4 數字電位器X9511W的應用 11
  3.3 數字控制文氏橋振蕩器設計方案 12
  3.4 數字控制文氏橋振蕩器的主要功能和要求 17
第4章 數字控制文氏橋振蕩器的仿真分析 18
  4.1 仿真軟件介紹 18
    4.1.1 直觀友好的圖形界面 18
    4.1.2 超強的仿真能力 18
    4.1.3 電路分析手段完備 18
    4.1.4 提供多種輸入輸出接口 18
  4.2 標準文氏橋振蕩電路的仿真 19
第5章 結束語 22
致謝 23
參考文獻 24
附錄 原理圖 25

摘要

 文氏橋振蕩電路是一種能將直流能源轉換成具有一定頻率和幅度以及一定波形的交流能量輸出的電路。數字式文氏橋具有調頻靈活、覆蓋范圍寬、功能強等特點，因而在通信、無線電、自動控制等許多領域有著廣泛的應用。
 本課題通過分析文氏橋振蕩電路特性，提出了數字式調頻的方案。選用X9511W數字電位器取代調頻支路電位器，通過調節該數字電位器阻值改變輸出信號頻率，同時為了滿足起振條件，負反饋熱敏電阻也用該電位器取代。
 課題進行了原理仿真和電路調試，理論上能夠滿足文氏橋振蕩器的調頻特性，但是受所選用數字電位器阻值調節分辨率限制，振蕩輸出信號調頻分辨率不高，同時信號易振蕩也是這個原因。

關鍵詞：文氏橋振蕩器；數字電位器； X9511W；調頻

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