一款20位无噪声分辨率ADC设计与测试

Design and Test of a 20bit Noise-Free Resolution ADC

ADC是信号处理系统的核心敏感器件,其测量精度直接影响信号系统的准确性。ΔΣADC相较传统的奈奎斯特ADC,通过噪声整形及过采样技术可以有效地获取极高的分辨精度。对于大部分测量类传感器应用,其信号频带接近于DC,所以低阶高过采样率调制器是最适用的一种解决方案。本文基于一款二阶ΔΣ调制器(MOD2)的设计,从系统建模到电路设计再到最终的流片测试均给出了详细数据。

ADC is the core sensitive component of the signal processing system,its measurement accuracy directly affects the accuracy of the signal system.Compared with traditional Nyquist ADCs,ΔΣADCs can effectively obtain extremely high resolution through noise shaping and oversampling techniques.For most measurement sensor applications,the signal frequency band is close to DC,so a low-order high oversampling rate modulator is the most suitable solution.This paper describes a second orderΔΣModulator(MOD2)design,from system modeling to the circuit design and final silicon test are given in detail.