OKAWA Electric Design
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(Sample)Sallen-Key Low-pass Filter Design Tool - Result -

Calculated the Transfer Function for the Sallen-Key low-pass filter, displayed on graphs, showing Bode diagram, Nyquist diagram, Impulse response and Step response.

Sallen-Key Low-pass Filter

Vin(s)→ →Vout(s)
(Sample)Transfer Function:
G(s)= 39401103.2309
s2+8888.88888889s+39401103.2309


R1 = 30kΩ
R2 = 18kΩ
C1 = 0.01uF
C2 = 0.0047uF

Cut-off frequency

fc = 999.020322137[Hz]

Quality factor

Q = 0.706165853583

Damping ratio

ζ = 0.708048962525

Pole(s)

p = -707.355302631 +705.471530171i[Hz]
  |p|= 999.020322137[Hz]
p = -707.355302631-705.471530171i[Hz]
  |p|= 999.020322137[Hz]

Phase margin

pm= NAN[deg] (f =0[Hz])

Oscillation frequency

f = 705.471530171[Hz]

Overshoot (in absolute value)

The 1st peak  gpk = 1.04 (t =0.00071[sec])
The 2nd peak  gpk = 1 (t =0.0014[sec])
The 3rd peak  gpk = 1 (t =0.0021[sec])

Final value of the step response (on the condition that the system converged when t goes to infinity)

g(∞) = 1

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
Analysis on frequency range:
  f1=∼f2=[Hz] (optional)

Transient analysis

Step response
Impulse response
Overshoot
Final value of the step response
Analysis on time range:
  0∼[sec] (optional)


Frequency analysis





Transient analysis