[SOLVED] Switched capacitor filter

[Vangrip]

Hi,

I have a simple question: I want to make an audio filter using switched capacitor filters (LMF100 - national). There is one problem however: I know I need to use a Bessel filter, but in the specs of these filtes, they don't say how you can create a bessel or butterworth filter. I guess it has something to do with the Q factor. Does anybody have any information on this or a few links with info?

thanks a lot!
Peter

 

[Polli]

You can take a look at rane.com. They are a producer of good PA equipment and crossovers. There are a lot of papers on there website about active filters for audio.

 

[sick_man]

:roll:

THE TYPE AND DIMENTION OF FILTERS NEEDED CAN BE FOUND IN THE DATASHEET FOR THE CHIP

BETTER MY PAL TO USE MULTISIM FOR THIS TYPE OF THING
IT IS ITS BEST QUALITY AS AN AMPLIFIER DESIGNER AND LOGIC DRIVER BOTH AUDIO SPECTRUM AND ABOVE
VERY EASY TO GET THE BEST FACTORING AND SPREAD
AS MULTISIM PROVIDES YOU WITH NICE GRAPHS AND CHARTS OF RESPONCE AND YOU CAN FIT THE CHIP IN AND WATCH IT WORKING IN REALTIME OR SO :smile:
WITH AUDIO GOING IN YOUR SOUNDCARD LINE IN AND THROUGH THE FILTER AND OUT THE SPEAKER OUTS
:smile:

COME ON MULTISIM !!!!!! :wink:

 

[Vangrip]

Hmm, is multisim capable of accurately simulating switched capacitor filters? I'm still working with ewb5.12 because I like the interface a lot more.

 

[bastos4321]

One of the best tools to simulate any switched capacitor circuit is the old switcap, and you can find it in filemanager.

About the filter, you can use matlab to have the transfer function and then design the filter.
Take a look in the Roubik and Temes book, Analog integrated circuits for signal processing, wily 1986.

 

[andy2000a]

a design tool called filter solution 9.1 support SCF..
but I don't know it can work on real SCF design ??

another filter design tool called filter wizard ..
someone use these tool on real analog IC design ??