Sallen Key lowpass filter calculator, Boode plotoct. 2015, Jeroen Korterik
The circuitThe Sallen Key implementation of a lowpass filter is shown below:
Boode plot of the transfer functionThe gain and fase vs. frequency response of the lowpass filter is shown below. Refer to the derivation of the response for more info (doc file).
How to use this toolThis webpage calculates the transfer of a 2nd order Sallen Key lowpass filter. Enter a value for R1 and the cutoff frequency and click calculate the values for R2, C1 and C2 in case of a Butterworth or Bessel response.
You can as well enter R1, C1 and C2 manually and check the response.
Results: cutoff frequency and q factor, Boode plot of the transfer function.