基于開關電容技術的鎖定放大器設計
所屬分類：技術論文
上傳者：serena
標簽： 鎖定放大器 開關電容
所需積分：1分積分不夠怎么辦,？
文檔介紹：鎖定放大是微弱信號檢測的重要手段,?；谙嚓P檢測理論,，利用開關電容的開關實現(xiàn)鎖定放大器中乘法器的功能,，提出開關電容和積分器相結(jié)合以實現(xiàn)相關檢測的方法,，并設計出一種鎖定放大器,。該鎖定放大器將微弱信號轉(zhuǎn)化為與之相關的方波,，通過后續(xù)電路得到正比于被測信號的直流電平,，為后續(xù)采集處理提供方便,。測量數(shù)據(jù)表明鎖定放大器前級可將10-6 A的電流轉(zhuǎn)換為10-1 V的電壓,，后級通過帶通濾波器級聯(lián)可將信號放大1×105倍。該方法在降低噪聲的同時,，可對微弱信號進行放大,，線性度較高、穩(wěn)定性較好,。 Lock-in Amplifying（LIA）is one of important means for weak signal detection. Based on cross-correlation detection theory,， switch in the swithched capacitor was used as multiplier of LIA， and a new method of correlation detection was proposed combining swithched capacitor with integrator. A kind of LIA was designed which can convert the weak signal to square-wave,， then DC proportional to measured signal was obtained through follow-up conditioning circuit,， providing convenience for signal acquisition and processing. The measured data shows that the electric current（10-6 A） can be changed into voltage（10-1 V） by LIA， and the signal is magnified 1×105 times by cascade band-pass filter. The noise is suppressed and the w
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