butterworth pi lc low pass filter calculator

enter the value, select the unit, and click calculate. the calculation results will be displayed.

enter a value:

cutoff frequency:

impedance z₀:

number of components:

(1-11)

calculation result:

inductance:

capacitance:

unit:

L₁:

C₁:

L₂:

C₂:

L₃:

C₃:

L₄:

C₄:

L₅:

C₅:

C₆:

butterworth pi lc low pass filter calculator

the characteristic of the butterworth filter is that the frequency response curve is the flattest in the passband, without fluctuations, and gradually drops to zero in the stopband. on the bode plot of the logarithm of amplitude versus angular frequency, starting from a certain boundary angular frequency, as the angular frequency increases, the amplitude gradually decreases, tending to negative infinity.

the first-order butterworth filter has attenuation rates of 6 db per octave and 20 db per decade. a second-order butterworth filter has an attenuation rate of 12db per octave, a third-order butterworth filter has an attenuation rate of 18db per octave, and so on. butterworth filter amplitude diagonal frequency

it decreases monotonically and is the only filter whose amplitude versus diagonal frequency curve maintains the same shape regardless of order. it’s just that the higher the filter order, the faster the amplitude attenuates in the stopband. for other filters, the amplitude versus corner frequency plot for higher orders has a different shape than the amplitude versus corner frequency plot for lower orders.

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