BJT differential pair

Discussion in 'General Electronics Chat' started by edcc, Feb 1, 2007.

  1. edcc

    Thread Starter New Member

    Feb 1, 2007
    1
    0
    can anyone explain to me when there is no need to have any resistor in the collector circuit of the two npn BJT differential pairs? The two BJT shares the same resistor in the emitter part and each of them have their own base resistors.

    be the way the circuit is supposed to be a level dector....

    Thanks a lot :)
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Can you post up the circuit? Not all differential pairs are alike.
     
  3. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    The 47K resistor is the collector resistor for T1. Think of T2 as a common collector amp.
     
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