基于FDCFOA的全差分混合模式二阶滤波器

Fully Differential Mixed Mode Biquadratic Filter Based on FDCFOA

提出了一种基于全差分电流反馈运算放大器(FDCFOA)的混合模式二阶滤波器电路.与CFOA实现该滤波器电路相比,可以大大降低总谐波失真(在100mV输入电压,1MHz的总谐波失真为3.60%).该电路在不改变电路结构的前提下就能同时实现全差分输入、输出电压模式和电流模式滤波器低通、高通和带通的功能.滤波器电路还具有灵敏度低,固有频率ω和品质因数Q可以独立调节.采用90nm CMOS工艺完成了PSPICE仿真,理论分析和仿真结果证明了电路的有效性.

A mixed mode biquadratic filter was presented based on fully differential current feedback operational amplifier（FDCFOA）.Compared with available CFOA circuits,the proposed filter circuit can reduce total harmonic distortion greatly（THD is 3.6% at 1 MHz of 100 mV input voltage）.The FDCFOA filter can realize fully differential input and output voltage mode（VM）and current mode（CM）low pass,high pass and band pass functions without changing circuit configuration simultaneously.The natural frequency can be adjusted independently without affecting quality factor,and the sensitivities are low.PSPICE simulations are completed using90 nm CMOS technology,theoretical analysis and simulation results verify the availability of the presented circuit.