应该是有源低通滤波器--
变形如下: [img]https://bbs.21ic.com/upfiles/img/20091/200911935120963.jpg[/img] [img]https://bbs.21ic.com/upfiles/img/20091/200911935236481.jpg[/img] [img]https://bbs.21ic.com/upfiles/img/20091/200911935342620.jpg[/img]
截止频率只能估计个大概,有时间最好自己仿真一下. |
|