ACTIVE_FILTER_

Published:2009/7/13 10:11:00 Author:May | From:SeekIC

Equal-value components can be quite an advantage in filter designs when the total costs associated with the procurement, stocking, and assembly of the filter are considered. For instance, the Butterworth active third-order low-pass filter (middle) uses equal-value resistors and capacitors. This feature normalizes the filter's 3-dB corner frequency to 1/RC (in radians) for both low-pass and high-pass designs. The graphs in (b) are plots of the ideal, normalized, and Sallen-Key low-pass filter frequency-domain magnitude and error responses. Note how both the normalized and Sallen-Key filters follow the ideal response well into the stopband. The error plots were created by plotting the difference between the real and ideal filter responses. The plots indicate that the normalized filter achieves performance results that are equal to those of the Sallen-Key low-pass filter.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/Filter_Circuit/ACTIVE_FILTER_.html

Print this Page | Comments | Reading(3)