Microchip Technology Inc

Digital Filter Design

Part Number: SW300001

The Digital Filter Design tool for the dsPIC®16-bit DigitalSignal Controllers makes designing, analyzing and implementing Finite Impulse Response (FIR) and InfiniteImpulse Response (IIR) digital filters easy through a menu driven and user intuitive interface. The filter design tool performs complex mathematical computations for filter design, provides superior graphical displays and generates comprehensive design reports. Desired filter frequency specifications are entered and the tool automatically generates the filter code and coefficient files ready to use in the MPLAB® Integrated Development Environment (IDE).System analysis of the filter transfer function is supported with multiple generated graphs such as: magnitude, phase,group delay, log magnitude, impulse response and pole/zero locations.

    Key features of the Digital Filter Design tool include:

    Finite Impulse Response Filter Design

  • Design Method Selection
    – FIR Windows Design
    – FIR Equiripple Design (Parks-McClellan)
  • Lowpass, Highpass, Bandpass and Bandstop filters
  • FIR filters can have up to 513 taps
  • Following window functions are supported:
    – Rectangular
    – Hanning (Hann)
    – Hamming
    – Triangular
    – Blackman
    – Exact Blackman
    – 3 Term Cosine
    – 3 Term Cosine with continuous 3rd Derivative
    – Minimum 3 Term Cosine
    – 4 Term Cosine
    – 4 Term Cosine with continuous 5th Derivative
    – Minimum 4 Term Cosine
    – Good 4 Term Blackman Harris
    – Harris Flat Top
    – Kaiser
    – Dolph-Tschebyscheff
    – Taylor
    – Gaussian
  • Reports show design details such as window
    coefficients and Impulse Response prior to multiplying
    by the window function

    Infinite Impulse Response Filter Design

    Lowpass, Highpass, Bandpass and Bandstop Filters

  • Filter orders up to 10 for Lowpass and Highpass
  • Filter orders up to 20 for Bandpass and Bandstop
  • Five Analog Prototype Filters are available:
    – Butterworth
    – Tschebyscheff
    – Inverse Tschebyscheff
    – Elliptic
    – Bessel
  • Digital Transformations are performed by Bilinear
    Transformation Method
  • Reports show design details such as all
    transformations from normalized lowpass filter to
    desired filter

    Code Generation Features

    Generated files are compliant with the Microchip
    dsPIC30F C30 Compiler, Assembler and Linker
  • Choice of placement of coefficients in Program Space
    or Data Space
  • C wrapper/header code generation


    Magnitude Response vs. Frequency
  • Log Magnitude vs. Frequency
  • Phase Response vs. Frequency
  • Group Delay vs. Frequency
  • Impulse Response vs. Time (per sample)
  • Step Response vs. Time (per sample)
  • Pole and Zero Locations (IIR only

    Host System Requirements 

    • PC-compatible system with an Intel Pentium®class or higher processor, or equivalent
  • A minimum of 16 MB RAM
  • A minimum of 40 MB available hard drive space
  • CD ROM drive
  • Microsoft Windows®98, Windows 2000, Windows XP or Windows NT®

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Last Updated
11/2/2009 5:25:48 PM