vco circuit

Discussion in 'The Projects Forum' started by suzuki, Sep 6, 2011.

  1. suzuki

    Thread Starter Member

    Aug 10, 2011
    119
    0
    deleted...
     
    Last edited: Oct 7, 2011
  2. suzuki

    Thread Starter Member

    Aug 10, 2011
    119
    0
    deleted...
     
    Last edited: Oct 7, 2011
  3. Hi-Z

    Member

    Jul 31, 2011
    157
    17
    Well, I suppose the unexpected simulation results are due to the fact that you're trying to use an op-amp as you would a comparator. Assuming you can, make the second op-amp a comparator (i.e. something which will accept a substantial differential input voltage, and which will provide a well-behaved logic output), and try it again.

    The same goes for a real-life circuit: op-amps aren't designed to be comparators, and the mosfet wouldn't particularly want to see a large negative voltage on its gate for that matter.
     
Loading...