active bandwidth filter , I want to know how it works

Discussion in 'Homework Help' started by Trương Xuân Phúc, Apr 11, 2019.

  1. Trương Xuân Phúc

    Thread Starter New Member

    Apr 11, 2019
    1
    0
    How does this circuit work?
    How many volts should it be given?

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  2. crutschow

    Expert

    Mar 14, 2008
    22,244
    6,491
    What do you mean "how it works"?
    Do you want a Laplace equation for its response, or just a description of its operation?

    I don't understand the question "How many volts should it be given?"
    That makes little sense.
     
  3. Papabravo

    Expert

    Feb 24, 2006
    12,164
    2,673
    A bandpass [not badwidth] filter will pass with minimal attenuation frequencies above a certain lower corner frequency up to an upper corner frequency. Above and below that range of frequencies the output will be 3 or more dB lower than the input.
     
  4. MrAl

    AAC Fanatic!

    Jun 17, 2014
    6,093
    1,311

    Hi,

    The short answer is, "It doesn't".

    That's because it is one heck of a crummy band pass filter, more like a band limiting filter.
    The bandwidth is more than 1MHz which is very strange for a op amp BP filter.
    My guess is that it has another application or else it is just not shown as connected properly.
    So dont give it any volts :)
    Instead, look for a better circuit there are lots out there.
     
  5. danadak

    Distinguished Member

    Mar 10, 2018
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    686
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    4,066
    1,774
    Here is another aide.
     
    MrAl likes this.
  7. Picbuster

    Well-Known Member

    Dec 2, 2013
    918
    119
    an active band filter using an opamp.
    As you know that amplification of an opamp is depending on Impedance feedback and impedance in.
    This will answer you question.
    If impedance feedback / impedance near to 1 then amplification is 1 approx.
    When impedance feedback is build from capacitor and resistor in parallel you are able to calculate the impedance as function of frequency.
    This is a measure for the band width.
    Same applies to input impedance.

    Please do the calculations with different values for imp in , imp out for different frequencies and plot this on paper.

    Picbuster
     
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