發(fā)布時間：2018-05-01 18:02

  本文選題：Sigma-Delta調制器 + 一位量化　； 參考：《哈爾濱理工大學》2015年碩士論文

【摘要】：硅微機械陀螺作為慣性傳感器大家族中的重要一員，無論在我們的日常生活中，或是工業(yè)生產中，甚至在軍工業(yè)上都不乏它的身影。其憑借著高精化、集成化、低能耗的特點已經成為了各大實驗室和研究所的科研重點。而Sigma-Delta調制器作為硅微機械陀螺中的接口模塊重要組成部分，不同于傳統(tǒng)調制器，它擁有更高的信噪比，在高精度模數轉換器上有著長足的發(fā)展。 本文針對硅微機械陀螺設計了一種四階前饋型Sigma-Delta調制器。其高精度的特性滿足了硅微機械陀螺接口模塊的設計要求。Sigma-Delta調制器高信噪比主要歸功于噪聲整形技術和過采樣技術。通過增加采樣頻率降低帶內的量化噪聲功率，由于Sigma-Delta調制器傳遞函數本身具有的低通特性，能夠將量化噪聲調制到高頻處經濾波器濾器，提高了精度。時鐘饋通效應和電荷注入效應是影響開關非理想特性的主要因素，通過開關上體端短接的補償結構可以使得方向等量電荷注入，有效抑制電荷注入效應。全差分放大器結構能夠抑制偶次諧波、時鐘饋通效應、噪聲等影響，高精度的Sigma-Delta調制器代表運算放大器要擁有足夠的增益，四階Sigma-Delta調制器一般需要40dB的直流增益。 通過MATLAB軟件中的Simulink建立非理想模型并通過仿真結果驗證方案可行性。本課題采用信號帶寬20kHz，采樣頻率為10.24MHz。首先得到其理想模型情況下的的信噪比為145.5dB，其有效位數為23位。通過加入非理想因素模型，得到的有效位數仍為20位，噪底低于-140dB，證明該系統(tǒng)方案滿足設計需求。在對系統(tǒng)電路進行整體設計之后，在Cadence軟件下對本設計進行仿真，得到本調制器有效位數為16位，噪底低于-120dB，，諧波淹沒在噪底當中，滿足設計要求。
[Abstract]:Silicon micromachined gyroscope is one of the most important members of inertial sensor family. It is not only in our daily life but also in industrial production and even in military industry. With the characteristics of high precision, integration and low energy consumption, it has become the scientific research focus of various laboratories and research institutes. As an important part of interface module in silicon micromachined gyroscope, Sigma-Delta modulator is different from traditional modulator. It has higher signal-to-noise ratio (SNR), and has a great development in high precision analog-to-digital converter (ADC). In this paper, a four-order feedforward Sigma-Delta modulator is designed for silicon micromachined gyroscope. Its high precision characteristics meet the design requirements of the interface module of silicon micromachined gyro. The high signal-to-noise ratio of Sigma-Delta modulator is mainly attributed to noise shaping technology and oversampling technology. By increasing the sampling frequency to reduce the quantized noise power in the band, the quantization noise can be modulated to the filter filter at the high frequency because of the low pass characteristic of the transfer function of the Sigma-Delta modulator, which improves the accuracy. Clock feed-through effect and charge injection effect are the main factors that affect the non-ideal characteristics of the switch. The directional charge injection can be effectively suppressed by the short junction compensation structure of the upper end of the switch. The structure of fully differential amplifier can suppress the influence of even harmonic, clock feedthrough effect, noise and so on. The high precision Sigma-Delta modulator represents that the operational amplifier must have enough gain, and the fourth order Sigma-Delta modulator generally needs the DC gain of 40dB. The non-ideal model is established by Simulink in MATLAB software and the feasibility of the scheme is verified by simulation results. The signal bandwidth is 20 kHz and the sampling frequency is 10.24 MHz. The signal-to-noise ratio (SNR) of the ideal model is 145.5 dB and the effective bit number is 23 bits. By adding the non-ideal factor model, the effective bit number is still 20 bits and the noise base is lower than -140 dB, which proves that the system scheme meets the design requirements. After the overall design of the system circuit, the design is simulated under the Cadence software. The effective bit number of the modulator is 16 bits, the noise base is lower than -120dB, and the harmonics are submerged in the noise bottom, which meets the design requirements.
【學位授予單位】：哈爾濱理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN761

【參考文獻】

相關期刊論文 前1條

1 魏本富,袁國順;∑-△模數轉換器研究進展[J];微電子學;2002年05期

本文編號：1830474