Sallen-Key Low-pass Filter Design Tool

This page is a web application that design a Sallen-Key low-pass filter. Use this utility to simulate the Transfer Function for filters at a given frequency, damping ratio ζ, Q or values of R and C. The response of the filter is displayed on graphs, showing Bode diagram, Nyquist diagram, Impulse response and Step response.

Calculate the transfer function for Sallen-Key low-pass filter with R and C values

Vin(s)→ →Vout(s)
Transfer function:
R1=Ω C1=F
R2=Ω C2=F
p:pico, n:nano, u:micro, k:kilo, M:mega

Frequency analysis

Bode diagram
    Phase  Group delay
Nyquist diagram
Pole, zero
Phase margin
Oscillation analysis

Upper and lower frequency limits:
  f1= - f2=[Hz] (frequency limits are optional)

Transient analysis

Step response
Impulse response
Overshoot
Final value of the step response

Simulation time:
  0 - [sec] (optional)


Calculate the R and C values for the Sallen-Key filter at a given frequency and Q factor

Vin(s)→ →Vout(s)
Cut-off frequency:
    
Transfer function:
    
fc=Hz

Q factor | Damping ratio ζ

Quality factor Q =
Damping ratio ζ =
C1 = F C2 = F
C1, C2 is optional. But when setting these capacitances, C1 and C2 of both are needed to give following the equation
  (C2/C1) ≤ ζ 2
  (C1/C2) ≥ 4Q2

Select Capacitor Sequence:
Select Resistor Sequence:

Frequency analysis

Bode diagram
    Phase  Group delay
Nyquist diagram
Pole, zero
Phase margin
Oscillation analysis

Upper and lower frequency limits:
  f1= - f2=[Hz] (frequency limits are optional)

Transient analysis

Step response
Impulse response
Overshoot
Final value of the step response

Simulation time:
  0 - [sec] (optional)


Calculate the transfer function for Sallen-Key low-pass filter with R and C values

Vin(s)→ →Vout(s)
Transfer function:
  Transfer function
R1=Ω C1=F
R2=Ω C2=F
R3=Ω
R4=Ω
p:pico, n:nano, u:micro, k:kilo, M:mega

Frequency analysis

Bode diagram
    Phase  Group delay
Nyquist diagram
Pole, zero
Phase margin
Oscillation analysis

Upper and lower frequency limits:
  f1= - f2=[Hz] (frequency limits are optional)

Transient analysis

Step response
Impulse response
Overshoot
Final value of the step response

Simulation time:
  0 - [sec] (optional)


Calculate the R and C values for the Sallen-Key filter at a given frequency and Q factor

Vin(s)→ →Vout(s)
Cut-off frequency:
    
Transfer function:
    
fc=Hz
G= at f=0Hz (G>1)

Q factor | Damping ratio ζ

Quality factor Q =
Damping ratio ζ =
C1 = F C2 = F
C1, C2 is optional. But when setting these capacitances, C1 and C2 of both are needed to give following the equation
  G-1 < C2/C1 ≤ ζ 2+G-1


Select Capacitor Sequence:
Select Resistor Sequence:

Frequency analysis

Bode diagram
    Phase  Group delay
Nyquist diagram
Pole, zero
Phase margin
Oscillation analysis

Upper and lower frequency limits:
  f1= - f2=[Hz] (frequency limits are optional)

Transient analysis

Step response
Impulse response
Overshoot
Final value of the step response

Simulation time:
  0 - [sec] (optional)