I wonder if any kind people can help me with this, I have never made any LP filter before, so some feedback would be appreciated:
I have a PWM signal that I can vary in frequency and I have chosen 10 kHz, 0-5 voltage. Then I want to put a second order SallenKey Low-Pass filter to the PWM so the signal filters.
My problem is to dimension the LP-filter and to get it to work. I’ve used this page from Analog device:**broken link removed**
and chosen: Fc to 10000 and “Gaussian to 12 dB” only for the convenience to get the capacitors to 94nF and 47nF. Then I have made the circuit and tested it but it doesn’t seems to work.
When I make a sweep from a function generator and trying different frequencies, nothing happens.
Am I missing something with the design? Are there any better method to filter the signal?
I have a PWM signal that I can vary in frequency and I have chosen 10 kHz, 0-5 voltage. Then I want to put a second order SallenKey Low-Pass filter to the PWM so the signal filters.
My problem is to dimension the LP-filter and to get it to work. I’ve used this page from Analog device:**broken link removed**
and chosen: Fc to 10000 and “Gaussian to 12 dB” only for the convenience to get the capacitors to 94nF and 47nF. Then I have made the circuit and tested it but it doesn’t seems to work.
When I make a sweep from a function generator and trying different frequencies, nothing happens.
Am I missing something with the design? Are there any better method to filter the signal?