Mosfet

Discussion in 'General Electronics Chat' started by power_hf, May 13, 2008.

  1. power_hf

    Thread Starter Member

    May 13, 2008
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    first, I'm a vietnamese and this is the first time I come here.I know this website through google.
    second, I have some problems , so I want your help.

    1/ as you know, n-mosfet has a gate (G), and I want to know the function of silicon dioxide layer and metal layer. What are their role in Mosfet?
    2/ the Enhancement-Mode MOSFET, I want a little information about it.
    my English is so bad :(.
    Thank you very much!
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    Try a search in google if you like about mosfet. But the silicon dioxide is used to insulate the gate terminal from the channel of the fet as to have a very high input impedance. The metal gate is used to distribute the electric field all over the channel.
    The enhancement mosfet in simple words behaves like a voltage controlled switch. When you apply a positive Vgs (for n-channel) it passes current (closed switch) through it , when you apply zero volts on Vgs the transistor behaves like an open switch.
     
  3. thingmaker3

    Retired Moderator

    May 16, 2005
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  4. Dave

    Retired Moderator

    Nov 17, 2003
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    mik3 has offered an answer to this one.

    The notion of enhancement-mode means that by applying a gate-voltage you are enhancing the source-drain connection by creating a conducting channel between these two points.

    The opposite of enhancement-mode is depletion-mode, which is where by applying a gate-voltage you are depleting the source-drain connection by removing a conducting channel between these two points.

    This also applies for other FETs including JFETs.

    Dave
     
  5. ametso

    Member

    Apr 30, 2008
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  6. power_hf

    Thread Starter Member

    May 13, 2008
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    you make me supprised because of your knowledge. I'm just a freshmen in electronics field.
    do you know about the structure of IC ?where can I read it? are there some websites about circuit that I can download their books without money? I'm poor!:p

    _what means "troubleshooting"? I have looked up many dictionaries , but they have no this word!
     
    Last edited: May 14, 2008
  7. nanovate

    Distinguished Member

    May 7, 2007
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  8. Wendy

    Moderator

    Mar 24, 2008
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    Trouble shoot.

    Trouble - problems, malfunctions.

    Shoot - To kill, to end.

    Troubleshoot - to analyze a malfunctioning circuit or machine to determine what is causing the problem, usually with the end goal to repair it.

    Don't worry about your english too much, I see folks whose native tongue is English that can't speak it correctly. I'm probably one of them.
     
  9. Dave

    Retired Moderator

    Nov 17, 2003
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  10. power_hf

    Thread Starter Member

    May 13, 2008
    11
    0
    Thanks alot all you.
     
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