I'm looking for information on the "Leapfrog", filter configuration. I know that one advantage over other filter configurations (Sallen-Key, Rauch) is lower component tolerance sensitivity. I'm looking for design equations for determining component values from the pole locations, sensitivity analysis, and any other design information that might be available. Regards, Jon
Leapfrog Filter
Oct 24, 2005
2 Replies
Certainly, especially for filters of high order and/or steep roll-off (high pole quality factor).
One article I reference is
A C M de Queiroz, L P Caloba, and E Sanchez-Sinencio. "Signal flow graph OTA?C integrated filters." In Proceedings of the International Symposium on Circuits and Systems, pages 2165?2168. IEEE, 1988.
You may want to note that "leapfrog" filters are equivalent to other filters derived from LC-R prototype passive filters, as noted in
L T Bruton. "Topological equivalence of inductorless ladder structures using integrators." IEEE Transactions CT, 20:434 ? 437, July 1973.
For this reason, you could look for design procedures under other names, such as "FDNR" or "gyrator-C," for instance
A C M de Queiroz and L P Caloba. "OTA?C simulation of passive filters via embedding." In Proceedings of the International Symposium on Circuits and Systems, pages 1083 ? 1086. IEEE, 1989.
A compilation of articles is
"Integrated Continuous-Time Filters: Principles, Design, and Applications" by Y. P. Tsividis, J. O. Voorman (Editor), Publisher: Institute of Electrical & Electronics Enginee; Reprint edition (January, 1993), ISBN: 078030425X
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Best Regards
Jens
Key ID 0x09723C12, jensting@tingleff.org
Analogue filtering / 5GHz RLAN / Mdk Linux / odds and ends
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Wow! Thanks, Jon
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