BJT Output char's (is it a CV or CC device ?)

Discussion in 'General Electronics Chat' started by nn_in, Feb 4, 2016.

  1. nn_in

    Thread Starter New Member

    Apr 14, 2009
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    a)In linear or active mode : For a give base current the collector current is constant even though the Vce can vary.across its terminal.
    b)In linear or active mode :If Vce is kept constant then collector current varies in propotion to base current

    So we can configure BJT as a CV or CC ?
     
  2. crutschow

    Expert

    Mar 14, 2008
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    3,229
    To a first order approximation, its a CC device when in the linear or active mode (not saturated).
     
  3. nn_in

    Thread Starter New Member

    Apr 14, 2009
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    0
    Thanks
     
  4. nn_in

    Thread Starter New Member

    Apr 14, 2009
    3
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    When the Vce Vs Ic is plotted for a given Ib
    a)with Vcc varying we reach a point where Ic (Y axis)is constant even though Vce (X axis) increases as Vcc is increased .Whats the significance of this ?
    Does this mean even though the Vce changes across its terminals for a given Ib ...the Ic will be constant !
     
  5. Papabravo

    Expert

    Feb 24, 2006
    10,138
    1,786
    In most cases the characteristic curves are not flat but have a slight upward slope. This means the collector current is nearly constant for a fixed base current, up to the point of destruction. In most cases it is the external circuitry that limits the collector current to a value that will prevent destruction. Increasing the base current doesn't get you more collector current because the device is saturated.
     
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