Filtroa Activos

User's Guide
SBFA001C – June 1991 – Revised February 2011

FilterPro™ User's Guide
.................................................................................................................. High-Performance Analog
ABSTRACT Although active filters are vital in modern electronics, their design and verification can be tedious and time-consuming. The FilterPro program is designed to aidin the design of active filters implemented with the multiple feedback (MFB) and Sallen-Key topology. This user's guide describes the information the designer must enter into the program and what the program delivers.

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Contents Filter Type Definitions ...................................................................................................... 3 FilterResponses ............................................................................................................ 7 Circuit Implementation ...................................................................................................... 8 Using FilterPro Desktop v3.1 ............................................................................................ 11 Changing Components inFilterPro Desktop ........................................................................... 22 Capacitor Selection ........................................................................................................ 23 Op Amp Selection ......................................................................................................... 23 The UAF42 Universal Active Filter...................................................................................... 25 Design Tools ............................................................................................................... 25 Migrating Designs from FilterPro v2.0 .................................................................................. 31 Important Notes............................................................................................................ 32 Conclusion .................................................................................................................. 37 List of Figures

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Low-Pass Filter Response ................................................................................................. 3 High-Pass Filter Response................................................................................................ 4 Bandpass Filter Response ................................................................................................. 5 Band-Reject or Bandstop Filter

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Response vs Frequency of Even-Order(Four-Pole), 3dB Ripple Chebyshev Filter Showing Cutoff at 0dB ............................................................................................................................ 7 Response vs Frequency of Odd-Order (Five-Pole), 3dB Ripple Chebyshev Filter Showing Cutoff at –3dB ..........................................................................................................................7 Real Pole Section (Unity-Gain, First-Order Butterworth; f–3dB = 1/2·π·R1·C1) ........................................ 9 Second-Order Low-Pass Filter ............................................................................................ 9 Third-Order Low-Pass Filter ............................................................................................... 9........................................ 9 Odd-Order Low-Pass Filter using Cascaded Complex Pole-Pair Sections Plus One Real-Pole Section ....... 9 MFB Complex Pole-Pair Section (Gain = – R2/R1) .................................................................... 10 Sallen-Key Complex Pole-Pair Section, Unity-Gain (Gain = 1) ..................................................... 10 Sallen-Key Complex Pole-Pair Section...