Linear phase filter low clock rate

[Bob Noger]

Has anyone used this range of _linear phase_ filters from LT? I was
wondering what the LOWEST clock rate might be. It is not given in the
data sheets.

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1154,C1008,C1148,P2062,D3068

I want to use it for a 40Hz (yes _Hz_) lowpass. If it won't work in
that app, can anyone please recommend a suitable linear phase filter?

Bob Noger

 

[[email protected]]

Has anyone used this range of _linear phase_ filters from LT? I was
wondering what the LOWEST clock rate might be. It is not given in the
data sheets.

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1154,C1008,....

I want to use it for a 40Hz (yes _Hz_) lowpass. If it won't work in
that app, can anyone please recommend a suitable linear phase filter?

Bob Noger

No reason why it shouldn't it's a low pass filter after all. You'll
have to clock it at a much slower rate (2-4kHz), Order one and try it
out. If for some reason it doesn't work you can make a 2-pole VCVS
filter from an opamp. Stringing four together can give you an 8-pole
response. (Do you need that much?) Horowitz and Hill have the design
equations for this. (You want the Bessel response)

George Herold

 

[Vladimir Vassilevsky]

Has anyone used this range of _linear phase_ filters from LT? I was
wondering what the LOWEST clock rate might be. It is not given in the
data sheets.

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1154,C1008,C1148,P2062,D3068

I want to use it for a 40Hz (yes _Hz_) lowpass. If it won't work in
that app, can anyone please recommend a suitable linear phase filter?

Why not DIY trivial analog filter using opamps or trivial digital filter
using a microcontroller?


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com