mosfet study

Discussion in 'Homework Help' started by zalavadiasatya, Dec 8, 2008.

  1. zalavadiasatya

    Thread Starter New Member

    Dec 8, 2008
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    i have question about mosfet i measure voltage at the gate 13.6 v and ammeter read 200 mA what is expect current at drain of mosfet ! and middle of drain and source has 68 ohm R2 anyone know about it please explain me


    thanks
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    Can you explain better what do you mean? A diagram (schematic) would be helpful if possible.
     
  3. Papabravo

    Expert

    Feb 24, 2006
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    200 mA into or out of the gate is a highly dubious claim. Maybe that current is an instantaneous value, because it cannot be sustained. You can draw any conclusion you want from a faulty premise.
     
    Last edited: Dec 9, 2008
  4. veritas

    Active Member

    Feb 7, 2008
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    I was wondering about that as well, since leakage current should be minimal.

    Regardless, there is not enough information here for me to provide an answer.
     
  5. Papabravo

    Expert

    Feb 24, 2006
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    1,791
    Right. As we all know a MOSFET gate is like a really large capacitor. Charging and discharging the voltage is a function of the integral of the current. The bigger the current source or sink the faster the gate will charge and discharge. There is also the plateau where the voltage remains constant while charge is added or removed.
     
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