A high-pass filter lets the highs pass and attenuates the lows.
The filter order represents the number of poles in the system. Basically the higher the order the steeper the cut-off slope.
I don't have the formulas to hand, but you should be able to find them in books such as Don Lancaster's Active Filter Cookbook (assuming an active filter).
The filter order represents the number of poles in the system. Basically the higher the order the steeper the cut-off slope.
I don't have the formulas to hand, but you should be able to find them in books such as Don Lancaster's Active Filter Cookbook (assuming an active filter).
Hi,
I think ESP has a couple of sections on active filter cutoffs and poles(slope), maybe also passive?
http://sound.westhost.com
For passive try Nelson Pass at http://www.passdiy.com
I think ESP has a couple of sections on active filter cutoffs and poles(slope), maybe also passive?
http://sound.westhost.com
For passive try Nelson Pass at http://www.passdiy.com
The filter order represents the number of poles in the system. Basically the higher the order the steeper the cut-off slope.
Another way of expressing this is: The order is the same as the amount of components that show a frequency-dependant behaviour (i.e. inductors and/or capacitors) in a filter.
Regards
Charles
APaddy said:
what is the 3rd order part ???
The other people have already answered most of your questions. However, the 3rd order part means that below the cutoff frequency, the level will roll off at 18dB per octave. A first order filter rolls off at 6dB/octave, a second order at 12dB/octave and so on. An octave is a halving (or doubling) in frequency.
Are you looking for a passive filter calculator?
If so, here's one: http://www.mhsoft.nl/spk_calc.asp
If so, here's one: http://www.mhsoft.nl/spk_calc.asp
What level of study are you at? If you want the calculations for why it's 3rd-order you are looking at A-Level+ maths calculus.
However, if you just want formula for calculating cut-off frequency and Q then it's a lot easier. Have you got a library you can go to and see if they have The Active Filter Cookbook by Don Lancaster?
However, if you just want formula for calculating cut-off frequency and Q then it's a lot easier. Have you got a library you can go to and see if they have The Active Filter Cookbook by Don Lancaster?
This one will give you the schematic diagram and the values. The proposed circuit is inverting however.
http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html
Regards
Charles
http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html
Regards
Charles
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