ElecFilDes includes many features not available in programs costing much more.
Source code for some of the more advanced portions of the program can be found under the software section of this site.
This program was developed using the text, Electronic Filter Analysis and Synthesis filter theory textbook, ISBN 0-89006-616-7 (Artech House, or Amazon.com on the Internet). Click books for more resources on filter design.
Features include:
Active filters Includes Butterworth, Tchebyscheff, inverse Tchebyscheff, elliptic designs
Filter orders to degree 40 (20 for elliptic).
Lowpass, bandpass, bandstop,and highpass variations
Provides a utility to estimate the filter order for analog (active and passive) and FIR digital filters, based on design requirements.
Includes multiple feedback, voltage controlled voltage source, and state-variable implementations.
Passive filters Elliptic filters with arbitrary source and load resistances (up to order 9)
Elliptic filters, evenly terminated, up to order 20 Lowpass, bandpass, bandstop, and highpass configurations
Allows canonical transforms on various passive filter sections.
Includes image parameter passive filter design utility.
Includes Butterworth and Tchebyscheff passive filters.
Generates PSPICE file for independent verification of all active and passive filters.
Generates source code for MC56F84789 DSP for FIR and IIR filters. Limited to order 20 for IIR and length 512 for FIR filters.
Limited to A/D sampling rates from 1 sample/sec to 100K samples/second.
32 bit arithmetic allows for ultra high Q audio filters with less than 1Hz bandpass to stopband transition.
Proprietary algorithm allows for IIR bandpass and bandstop filters with no anomolies.
Provides for real time implementation of FIR and IIR digital filters on MC56F8400 development board.
Various window design of FIR filters including rectangular, triangular, Hamming, Hanning, generalized Hamming, and Kaiser.
Remez exchange algorithm for FIR equiripple filters to length 512.
Numerous equations are shown analytically for educational purposes including Displays the input impedance equation set for unevenly terminated elliptic filters lowpass prototypes.
Displays the magnitude squared function for the lowpass prototype filters.
Shows the transfer functions for analog filters.
Displays poles and zeros for all analog and IIR filters.
Shows the DSP assembly code for FIR and IIR filters.
Provides the step and impulse response equations from the inverse Laplace transform utility.
Shows the equations for the canonical transform of passive filter sections.
Lowpass to bandpass, bandstop, and highpass transforms equations for analog filters are displayed.
Generates Martin & Sedra switched capacitor biquads based on the bi-linear transform.
Utilities include PLL analysis
RF directional coupler design
L-C matching
Resistive pad design
Symbolic analysis
Pspice (student version from Orcad) and LTspice (from Linear Tech) are license free software packages that can be used to simulate and verify the active and passive designs of ElecFilDes. Codewarrior 10.6 is a license free package from Freescale used to compile the assembly language files generated by ElecFilDes for IIR and FIR filters.
