Comparison - Filter Design vs. Filter Design Lite

M i c r o c h i p T e c h n o l o g y I n c o r p o r a t e d

Summary

The Digital Filter Design tool for the dsPIC®16-bit Digital Signal

Controllers makes designing, analyzing and implementing Finite

Impulse Response (FIR) and Infinite Impulse Response (IIR)

digital filters easy through a menu-driven and intuitive user

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.

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

4 Term Cosine

Hanning (Hann)

4 Term Cosine with

continuous 5th Derivative

Hamming

Minimum 4 Term Cosine

Triangular

Good 4 Term Blackman Harris

Blackman

Harris Flat Top

Exact Blackman

Kaiser

3 Term Cosine

Dolph-Tschebyscheff

3 Term Cosine with

Taylor

continuous 3rd Derivative

Minimum 3 Term Cosine

Gaussian

· Reports show design details such as window coefficients

and Impulse Response prior to multiplying by the window

function

· Filters are designed for a maximum gain of 1

Digital Filter Design/Digital Filter Design Lite

Infinite Impulse Response Filter Design

· Lowpass, Highpass, Bandpass and Bandstop Filters

· Filter orders up to 10 for Lowpass and Highpass Filters

· Filter orders up to 20 for Bandpass and Bandstop Filters

· 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

Graphs

· 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)

High-pass

Up to 513

Up to 64

FIR Taps

Band-pass

Band-stop

Up to 10

Up to 4

IIR Taps for LP, HP

Up to 20

Up to 8

IIR Taps for BP, BS

Generate ASM Code

Export to MPLAB® IDE

Export to MPLAB® C30 C Compiler

MATLAB® Support































Low-pass

Filter Design

Filter Design Lite

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