D類功放中數(shù)字脈寬調(diào)制器的研究與設(shè)計
發(fā)布時間：2018-10-16 09:37
【摘要】：隨著現(xiàn)代微電子技術(shù)的高速發(fā)展,數(shù)字音頻愈發(fā)普及。若要對數(shù)字音源放大輸出,對于傳統(tǒng)的模擬放大器而言,需要在音源與放大器之間加入高精度的數(shù)模(D/A)轉(zhuǎn)換器,提升了設(shè)計難度與成本。本文研究了一種利用全數(shù)字方式從數(shù)字音源信號直接到脈寬調(diào)制信號的轉(zhuǎn)換方案,避免了高精度D/A轉(zhuǎn)換器的引入,其過程如下：第一,本文對脈寬調(diào)制器的傳統(tǒng)結(jié)構(gòu)進行分析研究,討論了傳統(tǒng)脈寬調(diào)制器結(jié)構(gòu)的缺點和不足,而后引出本文所設(shè)計的基于Sigma-delta調(diào)制器的新型脈寬調(diào)制器結(jié)構(gòu)的解決方案。第二,通過研究與分析Sigma-delta調(diào)制器和噪聲整形的基本理論,針對基本的Sigma-delta調(diào)制器結(jié)構(gòu)進行改進,討論了兩種優(yōu)化后的高階Sigma-delta調(diào)制器結(jié)構(gòu)。第三,通過MATLAB仿真設(shè)計了一款5階7級Sigma-delta調(diào)制器。通過對噪聲傳輸函數(shù)(NTF)的設(shè)計推導(dǎo)出調(diào)制器整體參數(shù),而后仿真驗證了調(diào)制器的穩(wěn)定性及其輸入幅值限制。結(jié)果表明：所設(shè)計兩種方案的5階7級Sigma-delta調(diào)制器對量化器輸入信號幅值的限制都為1.8V,滿足數(shù)字音頻信號[-1,1]的幅度要求。對于加入零點優(yōu)化的方案結(jié)構(gòu)稍顯復(fù)雜但是相比于僅優(yōu)化極點分布的結(jié)構(gòu)103.2dB的信噪比,能夠達到更高的128dB信噪比。第四,為了給Sigma-delta調(diào)制器提供過采樣的輸入信號,本文基于對過采樣技術(shù)與數(shù)字信號采樣率轉(zhuǎn)換技術(shù)的研究,通過三種不同方案設(shè)計了一款32倍增采樣率轉(zhuǎn)換器。其中對于CIC+半帶濾波器和多相結(jié)構(gòu)濾波器進行了FPGA實現(xiàn)。又對三種設(shè)計方案進行優(yōu)劣比較。除原型FIR濾波器占用資源過大以外,另外兩種方案都很好地完成了對數(shù)字音頻信號的32倍增采樣任務(wù)。本文實現(xiàn)了一款基于Sigma-delta調(diào)制的新型脈寬調(diào)制器的設(shè)計,為數(shù)字音源與數(shù)字D類功放直接實現(xiàn)無縫結(jié)合提供了解決方案。
[Abstract]:With the rapid development of modern microelectronics technology, digital audio is becoming more and more popular. In order to amplify the output of digital audio source, it is necessary to add a high precision D / A converter between the audio source and the amplifier for the traditional analog amplifier, which increases the design difficulty and cost. In this paper, we study a conversion scheme from digital sound source signal to pulse width modulation signal in all-digital mode, which avoids the introduction of high-precision D / A converter. The process is as follows: first, In this paper, the traditional structure of pulse width modulator is analyzed, and the shortcomings and shortcomings of the structure of traditional pulse width modulator are discussed. Then, the solution of a new type of pulse width modulator based on Sigma-delta modulator is introduced. Secondly, by studying and analyzing the basic theory of Sigma-delta modulator and noise shaping, the structure of the basic Sigma-delta modulator is improved, and two optimized high-order Sigma-delta modulator structures are discussed. Thirdly, a 5-order 7-stage Sigma-delta modulator is designed by MATLAB simulation. The overall parameters of the modulator are derived from the design of the noise transfer function (NTF), and the stability of the modulator and the limitation of the input amplitude are verified by simulation. The results show that the amplitude of the quantizer input signal is 1.8V restricted by the 5-order 7-stage Sigma-delta modulator, which satisfies the amplitude requirement of digital audio signal. For the scheme with zero optimization, the signal-to-noise ratio (SNR) of the proposed scheme is slightly more complex than that of 103.2dB, which only optimizes the pole distribution, and can achieve a higher SNR of 128dB. Fourthly, in order to provide the input signal of over-sampling for Sigma-delta modulator, based on the research of over-sampling technology and digital signal sampling rate conversion technology, a 32-fold sampling rate converter is designed through three different schemes. Among them, CIC half band filter and polyphase structure filter are implemented by FPGA. The advantages and disadvantages of the three design schemes are also compared. Except that the prototype FIR filter takes up too much resources, the other two schemes have accomplished the task of 32 times sampling of digital audio signal. In this paper, a novel pulse width modulator based on Sigma-delta modulation is designed, which provides a solution for the seamless combination of digital audio source and digital D power amplifier.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN787.2;TN722.75
本文編號：2273946
[Abstract]:With the rapid development of modern microelectronics technology, digital audio is becoming more and more popular. In order to amplify the output of digital audio source, it is necessary to add a high precision D / A converter between the audio source and the amplifier for the traditional analog amplifier, which increases the design difficulty and cost. In this paper, we study a conversion scheme from digital sound source signal to pulse width modulation signal in all-digital mode, which avoids the introduction of high-precision D / A converter. The process is as follows: first, In this paper, the traditional structure of pulse width modulator is analyzed, and the shortcomings and shortcomings of the structure of traditional pulse width modulator are discussed. Then, the solution of a new type of pulse width modulator based on Sigma-delta modulator is introduced. Secondly, by studying and analyzing the basic theory of Sigma-delta modulator and noise shaping, the structure of the basic Sigma-delta modulator is improved, and two optimized high-order Sigma-delta modulator structures are discussed. Thirdly, a 5-order 7-stage Sigma-delta modulator is designed by MATLAB simulation. The overall parameters of the modulator are derived from the design of the noise transfer function (NTF), and the stability of the modulator and the limitation of the input amplitude are verified by simulation. The results show that the amplitude of the quantizer input signal is 1.8V restricted by the 5-order 7-stage Sigma-delta modulator, which satisfies the amplitude requirement of digital audio signal. For the scheme with zero optimization, the signal-to-noise ratio (SNR) of the proposed scheme is slightly more complex than that of 103.2dB, which only optimizes the pole distribution, and can achieve a higher SNR of 128dB. Fourthly, in order to provide the input signal of over-sampling for Sigma-delta modulator, based on the research of over-sampling technology and digital signal sampling rate conversion technology, a 32-fold sampling rate converter is designed through three different schemes. Among them, CIC half band filter and polyphase structure filter are implemented by FPGA. The advantages and disadvantages of the three design schemes are also compared. Except that the prototype FIR filter takes up too much resources, the other two schemes have accomplished the task of 32 times sampling of digital audio signal. In this paper, a novel pulse width modulator based on Sigma-delta modulation is designed, which provides a solution for the seamless combination of digital audio source and digital D power amplifier.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN787.2;TN722.75
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相關(guān)期刊論文 前2條
1 薛靜;欒英姿;;音頻ADC中Sigma-Delta調(diào)制器的工作原理和穩(wěn)定性研究[J];電子科技;2008年06期
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相關(guān)碩士學位論文 前1條
1 劉萬松;基于DSP的FIR數(shù)字濾波器的設(shè)計[D];貴州大學;2008年
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