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filters: Definition and Recommended Links

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In electronics, a digital filter is any electronic filter that works by performing digital mathematical operations on an intermediate form of a signal. This is in contrast to older analog filters which work entirely in the analog realm and must rely on physical networks of electronic components (such as resistors, capacitors, transistors, etc.) to achieve the desired filtering effect.

Digital filters can achieve virtually any filtering effect that can be expressed as a mathematical function or algorithm. The two primary limitations of digital filters are their speed (the filter can't operate any faster than the computer at the heart of the filter), and their cost. However as the cost of integrated circuits has continued to drop over time, digital filters have become increasingly commonplace and are now an essential element of many everyday objects such as radios, cellphones, and stereo receivers.

Source: Wikipedia (http://en.wikipedia.org/wiki/Digital_filters)

other great electronics sites:ee toolbox site

• • filters
    • In electronics, a digital filter is any electronic filter that works by performing digital mathematical operations on an intermediate form of a signal. This is in contrast to older analog filters which work entirely in the analog realm and must rely on physical networks of electronic components (such as resistors, capacitors, transistors, etc.) to achieve the desired filtering effect.

      Digital filters can achieve virtually any filtering effect that can be expressed as a mathematical function or algorithm. The two primary limitations of digital filters are their speed (the filter can't operate any faster than the computer at the heart of the filter), and their cost. However as the cost of integrated circuits has continued to drop over time, digital filters have become increasingly commonplace and are now an essential element of many everyday objects such as radios, cellphones, and stereo receivers.

      Source: Wikipedia (http://en.wikipedia.org/wiki/Digital_filters)

      (Note: The Electronic Engineers Toolbox provides an alternative set of featured links for this word at http://www.cera2.com/filters.htm)

      Featured Links:

      Introduction to Digital Filters With Audio Applications

      Introduction to Digital Filter Analysis Motivating Example and Overview FIR Filters Convolution Representation of LTI Filters Finiteness Causal FIR Filters Transfer Function Order
      http://www-ccrma.stanford.edu/~jos/filters/

      CMSA Filter Designer

      This tool allows the user to select parameters for a digital filter and draws the frequency response, on a linear graph or decibel graph, online. Currently, the possible filters that can be drawn include Chebyshev Type I and Type II, Butterworth, and FIR.
      http://dolphin.wmin.ac.uk/filter_design.html

      ScopeFIR Download

      ScopeFIR designs Complex Finite-Impulse Response (FIR) filters using the Parks-McClellan algorithm or windowing. You can then mix, scale, quantize, and edit the coefficients of the FIR filter. You may use ScopeFIR free for a 60-day trial period, but you must Register with Iowegian International Corporation in order to use it beyond the trial period. The full licensing terms for the program, plus additional information about Registration can...
      http://www.iowegian.com/download/loadfir.htm

      FIR Digital Filter Design Applet

      This JAVA applet allows you to design an FIR filter and view its characteristics. By choosing a window type, the filter order, and passband, you can design the filter and view its frequency response and get a listing of the coefficients. Source code available.
      http://www.dsptutor.freeuk.com/FIRFilterDesign/FIRFilterDesign.html

      Digital Filters: An Introduction

      This tutorial is a good, in-depth, yet easy to understand, explanation of digital filters. It includes digital filters' advantages, types, parameters, and it also has examples of simple filters. The site is HTML and the tutorial is also available as a PDF file.
      http://www.dsptutor.freeuk.com/dfilt1.htm

      Digital Filters @ Wikipedia

      In electronics, a digital filter is any electronic filter that works by performing digital mathematical operations on an intermediate form of a signal. This is in contrast to older analog filters which work entirely in the analog realm and must rely on physical networks of electronic components (such as resistors, capacitors, transistors, etc.) to achieve the desired filtering effect. Digital filters can achieve virtually any filtering...
      http://en.wikipedia.org/wiki/Digital_filter

      Introduction to DSP - IIR Filters

      This is the fifth module of the BORES Signal Processing DSP course - Introduction to DSP. It covers the following subjects: * IIR filter equations and frequency response * the z transform * the meaning of z * poles and zeroes * IIR filter design by impulse invariance * IIR filter design by the bilinear transform * direct form I and II filters * quantisation in IIR filters * IIR filter implementation structures
      http://www.bores.com/courses/intro/iir/

      Introduction to Digital Filters

      From introductory course in digital audio signal processing, which I have given at the Center for Computer Research in Music and Acoustics (CCRMA) since 1984. The course was created primarily as a first course in digital signal processing for entering Music Ph.D. students in the Computer Based Music Theory and Acoustics program. This book will emphasize audio and music applications . . .
      http://ccrma.stanford.edu/~jos/filters/

      FIR Filter FAQ

      This is a FAQ gives answers to questions about FIR filters, including the basics, FIR design, and links to related information.
      http://www.dspguru.com/info/faqs/firfaq.htm

      Digital Filter on the Web

      This personal page is a collection of tools created by the author to aid in digital filter design. Various JAVA applets allow the user to define and analyze IIR and FIR filters. The page also includes information for registration of the shareware tools to turn off any limitations.
      http://www.digitalfilter.com/

      Explanation: these links are provided as part of our EE glossary project, which seeks to identify the most prominent keywords in embedded systems, embedded software, realtime and rtos, dsp (digital signal processing), system-on-a-chip, microprocessors and microcontrollers, and other constituent elements for embedded systems. While we seek to keep most of the links up-to-date, the user is refered to other primary electronic-based search sites such as: cera2.com, embedded.com, or EDN Magazine. If you have any suggestions of links or definitions, please email!

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