Original scientific paper
Low-Noise Active-RC Allpole Filters Using Optimized Biquads
Dražen Jurišić
orcid.org/0000-0002-5263-5249
; Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, Croatia
George S. Moschytz
; School of Engineering, Bar-Ilan University, Ramat-Gan, Israel
Neven Mijat
; Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, Croatia
Abstract
In this paper it is shown that active-RC filters can be designed to have low-sensitivity to passive components and at the same time possess low output thermal noise. The design procedure of low-noise and low-sensitivity, positive-feedback, second- and third-order low-pass allpole filters, using impedance tapering, has already been published. The noise analysis in this paper was extended to the high-pass and band-pass filters and those with negative-feedback. The optimum designs, regarding both noise and sensitivity of most useful filter sections were summarized in the table form (as a cookbook) and demonstrated on examples. The classical methods were used to determine output noise spectral density and total rms output noise of filters. It was found that low-sensitivity filters with minimum noise have reduced resistance levels, low Q-factors, low-noise operational amplifiers and use impedance tapering design.
Keywords
Low sensitivity; Low noise; Low-; High- and Band-pass active-RC filters; Single-amplifier biquads; Allpole filters
Hrčak ID:
65059
URI
Publication date:
10.3.2011.
Visits: 2.386 *