四阶前馈结构Sigma Delta调制器在SIMULINK建模

该文主要介绍了采用一种前馈的sigma delta调制器结构。与传统sigma delta调制器结构相比较,这种结构减少了系统对器件,尤其是积分器的非线性敏感性,使其内部信号的摆幅减小,降低了对运放的要求,提高了输入信号的幅度和频率。基于以上特点,把该种结构应用于低电压环境中。该文采用四阶结构,处理信号带宽达到50kHz,采样频率为12.8MHz,过采样率为128。经过Simulink建模仿真表明,输入幅度达到参考电压的0.77,输入频率为40kHz时,SNR达到118.4dB。

Four-order Feedforward Sigma Delta Modulator Modeling in Simulink

This paper mainly introduces a Feedforward Sigma Delta Modulator. Compared to the traditional structure,it reduces the sensitivity of the system that depends on the components,especially the integrators, make the inner signal smaller,lower the index of operation amplifier,enhance the amplitude and frequency of the signal.Because of that,this structure is applied to low voltage environment.This paper adopt a Four-order structure,the bandwidth is 50kHz.Sampling frequency is 12.8MHz.The oversampling ratio is 128.Simulated in the Simulink,the input amplitude is 0.77 compared with the reference voltage,the input frequency is 40kHz,the SNR is reach to 118.4dB.