Hi all,(adsbygoogle = window.adsbygoogle || []).push({});

I am trying to design a lowpass filter using the following conditions

Passband edge f = 10 Khz (Ω_{p})

passband stop f = 30 Khz (Ω_{s})

Minimum stopband attenuation = 50db (1/A)

Maximum passband attenuation = 0.4db( 1/[itex]\sqrt{1+ε^{2}}[/itex] )

and am having quite a lot of trouble with it. I have tried to determine the order but it comes out as a complex number, the formula I am using is,

n= log( ε/[itex]\sqrt{(A^{2}-1)}[/itex])/log(Ω[/B]_{p}/Ω_{s})

can anyone help me out? Thanks

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# Designing a lowpass Butterworth filter

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