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    difference between active and passive filters

    For designing the band pass butterworth filter of 500kHz bandwidth and fL=200KHz and fH=800KHz which one is better solution?

    •   Alt12th December 2005, 07:55

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    difference between active and passive filter

    Active filters use amplifying elements, especially op amps, with resistors and capacitors in their feedback loops, to synthesize the desired filter characteristics. Active filters can have high input impedance, low output impedance, and virtually any arbitrary gain.
    They are also usually easier to design than passive filters. Possibly their most important attribute is that they lack inductors, thereby reducing the problems
    associated with those components.
    "A Basic Introduction to Filters–Active, Passive, and Switched-Capacitor"
    http://www.swarthmore.edu/NatSci/ech...oToFilters.pdf

    Regards,
    IanP



    •   Alt12th December 2005, 08:08

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    difference between passive and active filters

    if you can choose off chip method, that is better



    •   Alt12th December 2005, 09:38

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    active passive filters difference

    Thanks for reply,
    In my application ie for 200KHz to 800KHz which solution is better.
    Is active or passive?



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    difference between passive and active filters

    For resons quoted in my previous post I would go for active filters..

    Regards,
    IanP



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    different between active and passive filter

    Thanks Ian,

    I am also going with active filter but while designing i found that with smaller Q factor the passband is less.
    since our application is of higher frequency i am not getting flat response.
    Can u suggest any artical which helps in selecting correct opamp for that.

    with thanks



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    difference between active passive filters

    vasu,
    If you go the active route, the circuit must have considerable (i.e. >100) loop gain at the highest frequency of interest , in your case 800KHz. Otherwise the actual response will differ considerably from the ideal response.
    ~
    Some disadvantages of passive filters:
    Hard to design high Q inductors.
    Filter must be designed for specific source and load impedances.
    Regards,
    Kral



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    Re: difference between active and passive filters

    what are the major diferences between passive and active filters used in the electronic instrumentation??can anyone please help me...



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