C.E. Amp, Classical Bias Arrangement

Discussion in 'Homework Help' started by jegues, May 12, 2011.

  1. jegues

    Thread Starter Well-Known Member

    Sep 13, 2010
    735
    43
    Hello all,

    I'm just curious how the appropriate values of R1 and R2 are calculated for this specific problem.

    My work is attached.

    Any ideas?
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,957
    1,097
    Voltage divider must deliver 0.8V to the base.
    And the current which will flow through voltage divider must be larger then
    Ib_max = Ic/Hfe_min = 0.5mA/200 = 2.5uA
    So we can assume I = 20 * Ib_max = 50uA
    R1 = ( 9V - 0.8V) / ( 50uA + 2.5uA) = 156K = 160K
    R2 = 0.8V/50uA = 16K


    EDIT
    And it seems to me that Rout should be less than 5K
     
    Last edited: May 12, 2011
  3. jegues

    Thread Starter Well-Known Member

    Sep 13, 2010
    735
    43
    Whoops, I edited that typo on the hard copy and not my digital one.

    It is simply a typo.
     
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