Q值对连续时间Delta-Sigma模数转换电路的影响

摘要

为提高高速连续时间带通型Delta-Sigma模数转换电路的信号转换精度，分析内部谐振电路的有限Q值对转换电路整体SNDR (信号噪声+失真比)的影响，提出加入数字滤波电路的方法以改善模数转换电路的NTF (噪声传递函数)的方案，使电路SNDR提高15 dB以上。 Matlab建模及SPICE仿真证明了该方案的有效性。%This paper presented an analysis of finite Q factor effect of the system to improve the resolution of high speed continuous time Delta-Sigma AD modulator. By adding a digital filter to improve the NTF of modulator, the SNDR increased 15 dB. Matlab model and SPICE simulation confirmed the effectiveness of the proposed method.