一种新型Sigma-Delta ADC调制器的设计及验证

Design and Verification of a Novel Sigma-Delta ADC Modulator

Sigma-Delta ADC具有分辨率高、抑制噪声能力强等优点,适合用于涡街流量计系统中涡街信号的采样。因此,在典型Sigma-Delta调制器的基础上,根据涡街信号的特点设计了一种新型Sigma-Delta调制器。该调制器用两个比较器和一个不加外部时钟的D触发器控制积分输出方向,且电路参数由涡街信号的幅值和频率来确定。同时,这种设计克服了原本存在的积分输出可能饱和的问题。仿真实验证明,新型Sigma-Delta调制器可以将输入信号的幅值转化为输出脉冲的占空比,也可以减少噪声成分并保留频率信息,满足涡街信号的采样需求。

Based on the typical Sigma-Delta modulator structure and characteristics of vortex signal,a novel Sigma-Delta modulator is designed in this paper.Two comparators and a D flip-flop without an external clock are used as the controller of the integral output direction.The circuit parameters are determined by the amplitude and frequency of vortex signals.At the same time,this design overcomes the problem that the integral output may be saturated originally.