Sallen-Key High Pass Butterworth Filter Calculator
This calculator calculates the capacitor values for a unity gain Sallen-Key high pass Butterworth filter. The Sallen-Key filter is a simple active filter based on op-amps stages, which is ideal for filtering audio frequencies.
For a derivation of the design equations see this link:
High Pass Sallen-Key Design Equations
Quadradic: S^2+As+B.
Design equations:
R1= A/(4*C*PI*f)
R2= 1/(A*C*PI*f)
Derivation:
If normalized then Wo=1 and Q= 1/A. (See the design equation page for R1 and R2)
To use this calculator, select a resistance, the number of poles, and the cut-off frequency.
