Active 6Hz Bessel Lowpass filter Design

[djalli]

bessel filter design

Anybody knows how to design: Active 6Hz Bessel Lowpass filter? 1st order, 2nd order?
Frequency is very low 6Hz.

and thousands of thanks!

 

[ynhe]

bessel lowpass

You could use Anadigm's FPAA device(switched-capacitor filter) to do this.
There is a free design software could help you design.

see www.anadigm.com


ynhe

 

[djalli]

bessel filter design software

Oh I am sorry, I forgot to mention switched-capacitor are very-prone to aliasing. The reason I am choosing Bessel Filters for their excellence in phase-linearity.

Ynhe. many thanks. I did not know this kind of software.
.Nice to know

 

[ynhe]

filter 6hz

I just designed your 6Hz Bessel Lowpass filter using switched-capacitor,
The sampling frequency is about 0.5kHz that is much bigger than your corner frequency 6Hz.So. no aliasing.



ynhe

 

[flatulent]

bessel lowpass filter

linear Technology makes ICs with many filter responses. They also give away a design program for selecting the external resistors and capacitors. They have different models with the clock frequency being different multiples of the filter bandwidth.

You could precede this filter by a wider bandwidth op amp one to remove the aliasing signals.

 

[djalli]

2nd order bessel active op amp filter

flatulent you are a life savior