gardenyu
Newbie level 4
![Newbie level 4](/styles/images/ranks/blevel1.gif)
Sorry to bother you:
I just have problems when building a low-pass filter, the input signals are a 100 Hz 10V signal and a 5V 100k Hz one, they are combined at the input. I just need the 100 Hz signal at the output to turn on a microcontroller, (which I believe is low impedance). My questions are:
1. Do you have any recommened filter type: like second-oder, sallen-key or some other one? I just need as accurate as possible and not too complicated.
2. You have any recommended opamps? I need to build a through-hole one first.
3. as to bandwidth, it must follow the high freq signal or the low freq?
4. If the cap tolerance is a 20% one, is it a unstable factor? I don't want the 100 Hz signal to be eliminated at any time, it is an important signal.
Thank you very much.
I just have problems when building a low-pass filter, the input signals are a 100 Hz 10V signal and a 5V 100k Hz one, they are combined at the input. I just need the 100 Hz signal at the output to turn on a microcontroller, (which I believe is low impedance). My questions are:
1. Do you have any recommened filter type: like second-oder, sallen-key or some other one? I just need as accurate as possible and not too complicated.
2. You have any recommended opamps? I need to build a through-hole one first.
3. as to bandwidth, it must follow the high freq signal or the low freq?
4. If the cap tolerance is a 20% one, is it a unstable factor? I don't want the 100 Hz signal to be eliminated at any time, it is an important signal.
Thank you very much.