【摘要】：模數轉換器是現代測量領域重要的電子器件。高精度模數轉換器按照結構分類,通常包括逐次比較型、sigma-delt型、雙斜或多斜積分型以及電壓頻率型。論文研究了一種新型積分過采樣模數轉換器,該種結構轉換器具有較高線性度,千赫茲級信號帶寬。它比通用集成模數轉換器具有更高的精度性能,而比起常見的高精度專用模數轉換器具有更高的采樣率,其適用于電能計量儀器中,實現高精度電壓測量。為了驗證積分過采樣理論的正確性以及該種結構轉換器的可行性,論文設計了基于集成AD轉換器的專用型電壓測量或轉換電路,其構成了積分過采樣模數轉換器。論文主要工作為:1.分析積分過采樣模數轉換器的電路結構與工作過程,對經典量化噪聲與過采樣理論進行研究,推導出積分過采樣模數轉換器的信噪比公式以及臨界條件。2.分析積分過采樣模數轉換器的自校準設計方法,研究迭代自校準誤差項、電荷注入誤差項、集成ADC線性誤差項的校準流程以及相應補償方法。最后分析了補償放電時間誤差的兩種方法,分別為量化放電法與直接測量法。3.研究模數轉換器的測試理論。首先分析模數轉換器測試需遵循的相干條件,然后分析了測量靜態誤差的直方圖測試法以及測量動態精度的FFT測試法。最后使用matlab對模數轉換器的線性誤差、增益誤差、失調誤差建模,并對直方圖測試法以及FFT測試法進行仿真驗證。4.為驗證積分過采樣理論正確性與可行性,設計與實現18位積分過采樣模數轉換器。該轉換器使用14位集成模數轉換器積分過采樣16倍,其具有雙極性輸入電壓范圍-2~+2 V,采樣率10 kHz。5.搭建測試平臺,對該18位積分過采樣轉換器進行測試。通過碼密度測試,得到靜態精度:最大DLE小于0.8 LSB,最大ILE小于4 LSB。通過FFT測試,得到動態精度:噪聲和失真總和比為91.87 dB,信噪比為92.03 dB,總諧波失真比為-105.9 dB,無雜散動態范圍為-107.3 dB,有效位數14.96。
[Abstract]:Analog-to-digital converter (ADC) is an important electronic device in the field of modern measurement. High precision analog-to-digital converters are classified according to structure, including successive comparison type, sigma- delt type, double oblique or multi-oblique integral type and voltage frequency type. In this paper, a new type of integral oversampling analog-to-digital converter is studied, which has high linearity and kilohertz signal bandwidth. Compared with the general integrated analog-to-digital converter, it has higher accuracy and higher sampling rate than the common high-precision special analog-to-digital converter. It is suitable for electric energy metering instruments to achieve high-precision voltage measurement. In order to verify the correctness of integral oversampling theory and the feasibility of this kind of structural converter, a special voltage measurement or conversion circuit based on integrated AD converter is designed in this paper, which constitutes an integral oversampling analog-to-digital converter. The main work of this paper is as follows: 1. The circuit structure and working process of integral oversampling analog-to-digital converter are analyzed, the classical quantitative noise and oversampling theory are studied, and the signal-to-noise ratio formula and critical condition of integral oversampling analog-to-digital converter are derived. 2. The self-calibration design method of integral oversampling analog-to-digital converter is analyzed, and the iterative self-calibration error term, charge injection error term, calibration flow of integrated ADC linear error term and corresponding compensation method are studied. Finally, two methods to compensate the discharge time error are analyzed, which are quantitative discharge method and direct measurement method. The test theory of analog-to-digital converter is studied. Firstly, the coherence conditions to be followed in the test of analog-to-digital converter are analyzed, and then the histogram test method for measuring static error and the FFT test method for measuring dynamic accuracy are analyzed. Finally, matlab is used to model the linear error, gain error and misalignment error of analog-to-digital converter, and the histogram test method and FFT test method are simulated and verified. 4. In order to verify the correctness and feasibility of integral oversampling theory, an 18-bit integral oversampling analog-to-digital converter is designed and implemented. The converter uses 14-bit integrated analog-to-digital converter to integrate oversampling 16 times. It has a bipolar input voltage range of-2 V and a sampling rate of 10 kHz.5.. The 18-bit integral oversampling converter is tested by building a test platform. Through the code density test, the static accuracy is obtained: the maximum DLE is less than 0.8 LSB, the maximum ILE is less than 4 LSB.. Through FFT test, the dynamic accuracy is as follows: the sum ratio of noise to distortion is 91.87 dB, the total harmonic distortion ratio is 92.03 dB, and the total harmonic distortion ratio is-105.9 dB,. The effective number of effective bits is-107.3 dB,.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN792

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本文編號：2481173