Op Amp Circuit Identification

Discussion in 'Homework Help' started by stupidlogic, Apr 27, 2011.

  1. stupidlogic

    Thread Starter Member

    Aug 10, 2010
    I have an assignment with a bunch of op amp circuits (13 to be exact). I have been able to find reference and figure out all of them but two. One has two BJTs and the other has a BJT and a JFET and I'm having trouble even figuring out what they do. If someone could even just tell me that so I can look up some information, I'd appreciate it. Pictures of the circuits are attached.

    Thanks for the help.
  2. steveb

    Senior Member

    Jul 3, 2008
    The first circuit is a standard inverting opamp amplifier with a push-pull output stage added to boost the output current capability to the load. By applying the load voltage as the feedback (rather than the opamp output voltage), that voltage is precisely controlled.

    The second circuit appears to be a current source. They provide the equation for the current.
  3. Ron H

    AAC Fanatic!

    Apr 14, 2005
    To be precise, the second circuit is a current sink.:rolleyes:
  4. atferrari

    AAC Fanatic!

    Jan 6, 2004
    Wrong post. Please neglect.
    Last edited: Apr 28, 2011