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Finding the -3dB corner frequency of the circuit.

  1. Jan 18, 2012 #1
    Hey Everyone,

    The circuit I am interested in is attached. I was just looking for a little input to help me start this problem. As the title states I am just looking to find the -3dB frequency of this circuit.

    Point me in the right direction :)

    Attached Files:

  2. jcsd
  3. Jan 18, 2012 #2
    Write the equation for the output voltage as a function of frequency. Then using that equation, find the frequency that makes the output X times lower than the input where X is given by the equation below.

    3dB = 20 Log10(X).
  4. Jan 18, 2012 #3


    User Avatar

    Staff: Mentor

    The circuit begins with a voltage divider that cuts Vsource in half. That's already more than 3dB down (1/√2 ≈ 0.7071). Perhaps you're looking for where it's 3db down compared to a DC input voltage?
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