基于低电压电流放大器的高频二阶低通滤波器

A High-Frequency Second-Order Low-Pass Filter Based on a Low-Voltage Current Amplifier

介绍了用已报导的低电压电流放大器实现的电流型低通滤波器。该电路的结构简单，所用晶体管数很少。在器件完全匹配时，电路的寄生极点和零点在无穷远处，具有较好的高频特性。计算机仿真结果显示，当信号幅值低于偏置电流的１／２时，电路具有比较小的总谐波失真。

A current-mode low-pass filter based on a low-voltage current-mode amplifier is pre-sented.The filter is simple in circuitry and only a small munber of transistors are needed.With ful-ly matched transistors,the parasitic poles and zeros of the circuit are moved to infinity. Excellent high frequecy performance has been obtained for the circuit.Results from computer simulation in-dicate a amaller total harmonic distortion of the circuit as the amplitude of the input signals is low-er than 1/2 of the bias current.