In order to design a current mode filter which has the property of current controllability, the linear transformation filters by employing current mirrors as the elementary active elements are proposed. Based on the linear transformation, a simple and systematic design table is given to realize current-mode filters using current mirror. Using the proposed design table, all pole and elliptic filters can be designed easily. As an example, a new third-order elliptic lowpass filter is realized using only current mirrors and grounded capacitors. PSPICE simulations have been carried out using 0. 18 μm CMOS technology. The simulation results that comply with the theoretical analysis are obtained. The circuit has several advantages, such as low voltage (0.9 V), simple circuit, low filter sensitivities, adjustable cutoff frequency, which is suitable for full integration.%为了设计具有电流控制功能的电流模式滤波器,研究了应用电流镜实现高阶线性变换有源滤波器.基于线性变换,给出了实现电流模式电流镜滤波器的系统设计简表,以便于设计全极点与椭圆函数滤波器.通过实例实现了仅由电流镜和接地电容组成的三阶椭圆低通滤波器.并采用0.18 μm CMOS工艺对电路进行PSPICE仿真.仿真结果表明,该电路工作电压低(0.9 V),结构简单,灵敏度低,截止频率电流可调,适于全集成.
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