开关电容低通滤波器的设计

为了滤除信号中掺杂的高频噪声,设计一种六阶级联式开关电容低通滤波器,以数据采样技术代替传统有源RC滤波器中的大电阻,有利于电路的大规模集成。滤波器由双二阶子电路级联而成,电路中的电容值利用动态定标技术计算确定。用Hspice进行仿真验证,结果表明:开关电容低通滤波器能较好地对信号进行整形,其频率特性符合设计指标。

Design of switched-capacitor low-pass filter

In order to eliminate high-frequency noise doped in the signal,a sixth-order cascade switched-capacitor low-pass filter is designed in this paper.The data sampling technique is used in the filter to replace large resistances in the tranditional active RC filter,which is beneficial for large-scale integrated circuits.The filter is cascaded by biquad sub-circuits,the capacitance values in the circuit are calculated with dynamic range scaling technology.The simulation and valid results based on the Hspice show that the switched-capacitor low-pass filter can shape the signal effectively and the frequency characteristics meets design specifications.