How does diode work in transistor circuit?

Discussion in 'General Electronics Chat' started by Yadanar, Jan 27, 2015.

  1. Yadanar

    Thread Starter New Member

    Jan 27, 2015
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    What is the role of diode that connect between the base and the emitter of the transistor?
    (anode to the base and cathode to the emitter)
    I know diode permits current flow in only one direction. Are there more?
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,033
    3,241
    If you are talking about the intrinsic characteristics of the base-emitter junction, the "diode" is an inherent result of the base-emitter junction that forms part of the BJT structure. It is an artifact of the transistor design that looks like a diode when measured by itself but has no intentional "role" as a diode during normal transistor operation.
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,449
    3,363
    Are you referring to the P-N junction that is inherent at the base-emitter junction of an NPN BJT (bipolar junction transistor)?

    On its own it looks and behaves like a diode. In a transistor it plays a much more active role in that it controls the electron-hole flow within the transistor itself causing an increase of the collector-emitter current.
     
  4. #12

    Expert

    Nov 30, 2010
    16,330
    6,818
    This intrinsic diode usually has a reverse breakdown voltage between 4 volts and 6 volts. (It is not a very powerful diode.)
     
  5. Yadanar

    Thread Starter New Member

    Jan 27, 2015
    3
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    I need to study more detail!
     
  6. Yadanar

    Thread Starter New Member

    Jan 27, 2015
    3
    0
    Thank!
    I need to study more detail!
     
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