基于CCTA的可级联的电流模式多功能滤波器

Cascadable current-mode multifunction filter configuration using CCTA

通过级联积分器单元的方式,设计了一种基于电流传输跨导放大器(CCTA)的可级联的电流模式多功能高阶滤波结构。通过选择合适的输入电流,该结构能够同时实现低通、带通、高通和带阻等功能,其品质因素Q和角频率ω0都可以通过调整CCTA的偏置电流(IB)来实现电调谐。此n阶滤波器仅仅包含n个CCTA和n个接地电容,具有最少的有源和无源器件数目,电路结构简单,非常适合制作全集成IC。最后采用PSPICE仿真验证了所设计电路的性能。

A cascadable current-mode multifunction filter using CCTA is proposed. By properly selecting the applied input currents; it can simultaneously realize low-pass, band-pass, all-pass, and high-pass and band-reject responses from one topology without any component matching conditions. Both of the parameter coo and Q can be tuned electronically inde- pendently over a wide range by varying the bias current（ 18 ） of the CCTA without affecting each other. Additionally, the proposed nth-order filter is only composed by n CCTAs and n grounded capacitors. So the configuration has the least number of passive and active components;the proposed configuration enjoys having Simple structure, and it is highly suit- able for IC implementation. The realized circuits are simulated with SPICE to exhibit its performance.