具有宽调谐范围的低电压对数域二阶低通滤波器

A Second-Order Low-Pass Log-Domain Filter with Large Tuning Range and Low-Voltage

提出了一个由 Bi CMOS构成的对数域二阶低通滤波器 ,并采用跨导线性原理分析得到其传递函数。分析了晶体管的寄生电容对此滤波器频率特性的影响。PSpice仿真结果表明 ,该对数域低通二阶节的实际频率特性和理想特性基本一致 ,且具有宽频率调谐范围、低工作电压和低失真等特点 ,可用于对数域高阶滤波器的设计。

A second order low pass log domain filter based on BiCMOS is presented.The transfer function is given by using translinear principle.Effects of the parasitic capacitance on the frequency response of the filter are studied.The practical frequency response is about the same as the ideal frequency response for the second order low pass log domain filter.The filter, which has large tuning range, low voltage and low distortion, has been confirmed by means of PSpice simulations and can be used for the designs of higher order log domain filters