Characteristic Impedance of LC Filter

[iamakda]

What is exactly the meaning of the Characteristic Impedance of the LC filter? I know the formula that is SQRT(L/C), but please tell me what does it mean?

Thanks.

[Longbow]

Re: Characteristic Impedance of LC Filter

Characteristic impedance is a term most often used to refer to a transmission line with distributed constants. Shape factor is a better term to describe the characteristics of a particular filter. An LC filter is made up of lumped constants. The resonant frequency in Hz of an LC filter is one on 2pi root LC.

As usual, nothing exists in space, so you often must define what your source and load impedances should be in order for your filter to work properly. Ideally the source and load would be resistive, so they don't interfere with the resonant frequency or the shape of the filter. Ideally, the source and load impedance would be infinite, in order to maximize the Q of the LC circuit.