本压缩包包含了多种滤波，包括；反相输入二阶低通有源滤波器，反相输入一阶低通有源滤波器，四阶有源带通滤波器，同相输入二阶低通有源滤波器等多种。-This archive contains a variety of filtering, including inverting input second-order low-pass active filter, inverting input a first-order low-pass active filter, the fourth-orde