Software para projeto de Filtros
Filtros Analógicos
FilterLab - Microchip
FilterLab allows the design of low-pass, high-pass and band-pass filters up to an 8th order filter with Chebyshev, Bessel or Butterworth responses from frequencies of 0.1 Hz to 10 MHz. Users can select a flat passband or sharp transition from passband to stopband. Options, such as minimum ripple factor, sharp transition and linear phase delay, are available. Once the filter response has been identified, FilterLab generates the frequency response and the circuit. For maximum design flexibility, changes in capacitor values can be implemented to fit the demands of the application. FilterLab will recalculate all values to meet the desired response, allowing real-world values to be substituted or changed as part of the design process.
FilterPro - Texas Instruments
FilterPro™ Multiple Feedback (MFB) and Sallen-Key Design Program is a Windows application. This application designs MFB and Sallen-Key low-pass and high-pass filters using Voltage Feedback Op Amps, resistors and capacitors. It also supports a fully-differential version of the MFB circuit. This program includes Bessell, Butterworth, Chebychev, and linear phase filter types and can be used to design filters from 1 to 10 poles. The capacitor values in each stage can be either selected by the computer or entered by the designer. An "always on" prompt window provides context-sensitive help information to the user. The response of the filter is displayed on a graph, showing gain, phase and group delay over frequency.
A new version of FilterPro™ is now available, Version 2.0, that includes band-pass, notch, wide-band-pass, and band-reject circuits. Band-pass circuit is based on the MFB circuit. Because the band-pass filter is most often used for tone detection and high Q filters usually need high gain, a method was found to make the gain equal to the Q of the filter. Notch circuit is a dual amplifier circuit whose sensitivity to variation of passive components is also reduced compared to the traditional twin-T circuit. Wide-band-pass filter uses a high-pass filter cascaded with a low-pass filter. Band-reject filter uses a high-pass filter summed with a low-pass filter. This is useful to block a wide band of frequencies. It is also useful if the gain above the blocked band of frequencies is desired to be different than the gain below the blocked band.
- versão 2.0 - download TI CEFETSC Esta versão apresenta alguns problemas no projeto de filtros Passa Faixa, e na escala logarítmica dos diagramas de bode.
Filtros Digitais
FGEN for Windows - Microstar Laboratories
FGEN can produce several filter types: lowpass, highpass, bandpass, bandstop, running average, Window vectors and Blackman, Hamming, and Hanning window vectors are available. FGEN also provides plots of filter response as dB vs. frequency and as amplitude vs. frequency. FGEN computes the filter coefficients of FIR digital filters. There are four types of digital filters: Lowpass, Highpass, Bandpass, and Bandstop. The number of taps can take any odd value in the range of 3 to 511. Lower limits apply to all filter types. Upper limits apply only to bandpass and bandstop filters. There are four types of windowing: Blackman, Hamming, von Hann, and Rectangular. Under the file menu option, you can copy and view the filter coefficients.
SuperFilter - Those Engineers Ltd
With SuperFilter you can Design the following classical analogue filter types, in both active and passive forms: Butterworth, Chebyshev, Elliptical, Bessel. Realise Digital filters as: IIR Recursive designs, FIR Non Recursive designs. Describe your designs using: pole-zero description, filter order and cut off, pass band and stop band. See the frequency and transient response of all your filter designs.