基于[CF+]的四阶电流模式低通滤波器分析

Fourth-Order Low Pass Filter Using Current Followers

提出了以信号电流跟随器CF +为基本电路元件 ,构成全集成MOSFET -C精确连续时间四阶电流模式平衡结构低通滤波器电路 ,应用PSPICE(Ⅱ )通用模拟电路程序 ,对其幅频特性和相频特性进行了计算机仿真分析 .结果表明 :这种滤波器能够直接处理电流信号 ,避免了电压跟随误差对电路品质因数和自然频率的影响 ,有效地消除了MOSFET电阻偶次非线性因素的影响 。

A fully integrated current version precision continuous time of fourth order low pass filter with balanced structure based on current followers CF+ is presented. The characteristics of the output voltage amplitude frequency and phase frequency response of filter have been simulated and analyzed by using the PSPICE(Ⅱ). The current signal could be directly processed, the influence of the voltage tracking error on the quality factor and natural frequency could be avoided, and the even nonlinearities of the MOSFET resistors could be cancelled by this filter.