低成本高輸入阻抗前置放大器設(shè)計(jì)與制作

電子信息工程論文編號:DZXX089  論文字?jǐn)?shù):9719,頁數(shù):26   

目錄
 
摘要 ................................................................I
ABSTRACT ...........................................................II
第一章 引言 .........................................................1
1.1背景 ............................................................1
1.2 設(shè)計(jì)內(nèi)容 .......................................................1
第二章 放大器性能指標(biāo)及其測試 ......................................2
2.1 開環(huán)差模電壓放大倍數(shù) ...........................................2
2.2 共模抑制比 .....................................................3
2.3 差模輸入電阻 ...................................................4
2.4 失調(diào) ...........................................................4
第三章 高輸入阻抗放大器 ............................................6
3.1 輸入阻抗的概念 .................................................6
3.2 提高輸入阻抗的實(shí)用方法 .........................................6
3.2.1輸入級加場效應(yīng)管 ............................................6
3.2.2自舉 ........................................................7
第四章 實(shí)用高輸入阻抗電路設(shè)計(jì) ......................................13
4.1放大器的選擇 ...................................................13
4.2電路設(shè)計(jì) .......................................................15
4.2.1 設(shè)計(jì)原理總圖................................................15
4.2.2 模塊分析....................................................15
4.3輸入阻抗的測定 .................................................17
致謝 ...............................................................21
參考文獻(xiàn) ...........................................................22
附錄：元件清單......................................................23

摘要
 高輸入阻抗的放大器的一個(gè)非常普遍的用途，是用來放大如加速度計(jì)、拾音器等晶體換能器這類傳感器的輸出信號。這類傳感器的內(nèi)阻抗很高，而輸出的信號微弱，因此需要傳感器的前置放大器具有高的輸入阻抗，才能獲取傳感器的輸出信號。
 在電路設(shè)計(jì)過程中，常�？梢岳�用自舉電容構(gòu)成的自舉電路來改善電路的一些性能指標(biāo)，比如增大電路的輸入阻抗、提高電路的增益以及擴(kuò)大電路的動態(tài)范圍等等，本文通過對放大器的基本分析，比較目前各種常見的高輸入阻抗放大器及其工作原理，并根據(jù)任務(wù)要求，提出并制作利用普通四運(yùn)放和自舉電容搭建一低成本的高輸入阻抗電路。
 關(guān)鍵詞：高輸入阻抗，自舉電路， 運(yùn)放
 
  
ABSTRACT
     High input impedance of the amplifier's have very common use, usually they are used to enlarge such as accelerometers, pickups and other crystal transducer output signal of such sensors. Internal impedance of these sensors is high, the output of the signal is weak. Sensor preamplifier should have high input impedance, to obtain the sensor output signal.
     In the circuit design process, often use the bootstrap capacitor bootstrap circuit consisting of a number of performance indicators to improve the circuit, Such as increasing the circuit's input impedance, improve the circuit's gain and expand of the circuit's dynamic range, etc. Based on the amplifier's basic analysis , make comparison of all common high-current amplifier input impedance and working principle. And in accordance with task requirements, put forward and make use of ordinary quad op amp and build a bootstrap capacitor low-cost high input impedance circuit.
  Keywords: High input impedance, Bootstrap circuit, Op amp