高阶Σ-△调制器的滑模电路设计方法

Sliding Mode Circuit Design of High-Order Σ-△ Modulators

提出了一种新的高阶Σ-△调制器滑模电路设计方法.首先,证明了滑模控制系统的Σ-△调制编码功能,进而推出了Σ-△调制器传输函数形式的稳定性判据;然后,结合判据提出了一种稳定的巴特沃斯极点、零点优化的传输函数设计算法;最后,利用建立参数方程及求解、参数仿真调整,设计了Σ-△调制器的环路滤波器级联结构的电路,并通过一个设计实例及仿真,验证了所提方法的可行性.

A novel sliding mode circuit approach for implementing high-order Σ-△ modulators is proposed in this paper.Firstly,the Σ-△ modulating coding function is prooved,and then the stability criterion of transfer function for high-order Σ-△ modulators is deduced.Secondly,the stability design algorithm of transfer function using the deduced criterion,Butterworth poles and zeros optimization is introduced.Finally,the circuit implementation of Σ-△ modulators with cascading loop-filters is completed by using the solution of parameter equations and simulation modifications.A design example and simulation results verify that the proposed method is feasible.