The discussion revolves around designing a filter with a specific frequency response, particularly focusing on the relationship between frequency and decibels (dB). Participants explore how to determine the -6dB point for a filter with a 24dB/oct slope, starting at 0dB at 90Hz, and consider various filter topologies such as Butterworth, Chebyshev, and Elliptical.
Participants express differing views on the disadvantages of sharper filters and the implications of filter topology on design choices. No consensus is reached regarding the main disadvantage of sharper filters.
Participants mention the need to consider real-world factors such as component tolerances and the characteristics of different filter topologies, which may affect the design and performance of the filter.
Nope. Hint -- you need to order the resistors and capacitors from Digikey to build your filter. Read the datasheets from digikey for the real components, and resimulate the filter response, based on the published tolerances. See any problems?frogdogbb said:I don't know what is the main disadvantage? Size, added complexity? It is an active filter so componet losses are not really an issue.
BTW, keep in mind that the different topology filters have different characteristics in the passbands and stop bands, as well as different knee sharpness characteristics. The Butterworth is flat and slow, the Cheby is better if you can tolerate some ripple in the passband (not 0dB all across), and the Elliptical is better yet in terms of a sharp knee, if you can tolerate gain ripple in both the passband and stopband.frogdogbb said:Hello all, I am having trouble figures out the following filter I am designing. I to use a filter with a 24db/oct slope I want 0dB@90hz. So if I want the knee of the cuttof curve to start at 90Hz how do I find the -6dB point so I can design the crossover, by the way this filter uses -6dB as the crossover point as opposed to the usual -3dB.
Thanks