 25th March 2009, 04:59 #1
 Join Date
 Sep 2006
 Posts
 190
 Helped
 9 / 9
 Points
 2,702
 Level
 12
chebyshev filter
what's the basic differences between butterworth & chebyshev filter ?
 25th March 2009, 04:59
 25th March 2009, 07:07 #2pauloynskiGuest
butterworth chebyshev filter
Here is a comparison. Please google for a while to find many others. http://en.wikipedia.org/wiki/Chebyshev_filter
Added after 1 hours 42 minutes:
Download and install FilterPRO to simulate them http://focus.ti.com/docs/toolsw/fold...filterpro.html
 25th March 2009, 09:55 #3
 Join Date
 May 2008
 Location
 Germany
 Posts
 5,212
 Helped
 1542 / 1542
 Points
 36,437
 Level
 46
butterworth and chebyshev filters
In words:
Butterworth low pass exhibits a maximally flat response within the pass region;
Chebyshev response has some ripple within this region, however, in the transition region it is somewhat steeper.
 25th March 2009, 09:55
 28th March 2009, 01:12 #4
 Join Date
 Mar 2005
 Location
 USA
 Posts
 1,323
 Helped
 272 / 272
 Points
 11,390
 Level
 25
chebyshev butterworth
desperado1,
The Butterworth filter is maximally flat It optimal is in the sense that of all possible filters with a monotonic passband and a monotonic stop band, it has the minimum attenuation in the pass band.
.
The Chebychev filter is optimum in the sense that of all filters with a monotonic stop band (ripple allowed in the passband), it has the steepest transition region.
Regards,
Kral
 29th March 2009, 17:03 #5
 Join Date
 Jun 2008
 Posts
 1,180
 Helped
 36 / 36
 Points
 8,202
 Level
 21
butterworth chebyshev
ALSO THINK WHAT PHASE SHIFT EACH FILTER GIVES.AND THE LEVEL OF DISTORTION (sorry about caps)
 30th March 2009, 07:04 #6
 Join Date
 May 2008
 Location
 Pakistan
 Posts
 401
 Helped
 52 / 52
 Points
 4,634
 Level
 16
chebyshev butterworth filters
both r basically mathematical function,butterworth is flat in it pass band but it's transition band is not much abrupt,where chabyshev has ripples in pass band but its transition band is abrupt so it signal dies out quickly,
it is basically trade off b/w passband n transition band
 30th March 2009, 15:14 #7
 Join Date
 Mar 2005
 Location
 USA
 Posts
 1,323
 Helped
 272 / 272
 Points
 11,390
 Level
 25
butterworth and chebyshev filter
The phase linearity of the Butterworth is better than that of the Chebyshev. In other words, the group delay (derivative of phase with respect to frequency) is more constant with respect to frequency. This means that the waveform distortion of the Butterworth is lower. Of course, with a single input frequency, there is no waveform dostortion in either filter.
Regards,
Kral
Added after 4 minutes:
Another point to consider; the Butterworth filter is completely defined mathematically by 2 parameters: Cutoff frequency and number of poles. The Chebyshev filter has a third parameter: Passband Ripple.
Regards,
Kral
LinkBacks (?)

Untitled document
Refback This thread2nd September 2014, 18:10