Original scientific paper
https://doi.org/10.7305/automatika.54-2.308
A Novel Third-Order Leap-Frog Active Filter
Neven Mijat
; Department of Electronic Systems and Information Processing, Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000, Zagreb, Croatia
Dražen Jurišić
orcid.org/0000-0002-5263-5249
; Department of Electronic Systems and Information Processing, Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000, Zagreb, Croatia
George S. Moschytz
; Faculty of Engineering, Bar-Ilan University, Ramat-Gan, IL-52900, Israel
Abstract
This paper presents the realization of third-order low-pass active-RC filters using a new Leap-Frog (LF) topology. New structure is a simplified LF structure with the elements calculated directly from the transfer function coefficients. Several versions of the circuits are presented and compared. The comparison to other common thirdorder filter sections is done, as well. The new LF filter has the reduced number of components, reduced complexity and straightforward design procedure compared to classical filters. As an illustration of the efficiency of the proposed new LF filter, the sensitivity analysis using Schoeffler sensitivity measure as well as output thermal noise analysis was performed on examples with Butterworth and Chebyshev 0.5dB pass-band ripple transfer functions. Using PSpice with a TL081 opamp model, the filter performance is simulated and the results compared and verified by measurements on a discrete-component breadboard filter. All equations needed for the step-by-step design are given.
Keywords
Leap-Frog filters; Third-Order filter sections; Low-Sensitivity and low-noise filters; Active-RC filters
Hrčak ID:
103422
URI
Publication date:
2.5.2013.
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