#Pi filters design how to

#Pi filters design how to

Its surprising how many engineers don't know how to do stuff like this, how many engineers can solve the quartic equation the above yields?. Set to 0.707 and solve for W, This will give you the equation for the -3db point, I won't post the equation here, its not common to find it online, its much more complicated than you are giving it credit for, Its not as easy as working with first order filters, which as far as I can tell is all the OP needs anyway Insert S=jw, square, equate real and imaginary then take the square root Plot the circuit, add in a parasitic R, then calculate the transfer function Sorry but this isnt right, you set them equal to each other, put in your W (desired resonant frequency) in order to work out the values for resonance!, this way you are designing a system to resonate Suppose you want the cut off frequency, that is the frequency where the input value is cut by a half at the output, called F, you make This is where the 1/(LC)^0.5 equation comes from Thats the resonant frequency, exciting an LC filter with its resonant frequency is normally what you design to avoid! You want the inductive reactance to be the same as the capacitave reactance