Mosfet

Discussion in 'General Electronics Chat' started by f45hil, Feb 24, 2012.

  1. f45hil

    Thread Starter New Member

    Feb 24, 2012
    2
    0
    In which region MOSFET works as an amplifier and in which region MOSFET works as a switch? Does MOSFET work as a switch in the saturation region?
     
  2. nigelwright7557

    Senior Member

    May 10, 2008
    487
    71
    A MOSFET can work in the linear region for a class AB amp or in switching mode for a class D amplifier.
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Generally if you need a transistor in the linear region you use a BJT, not a MOSFET. A BJT has a wider range that is truly linear, while a MOSFET is a really good switch, with a incredibly low conductance when it is on (well under 0.1Ω typically).

    If you must use a MOSFET in its linear region then be aware you are throwing away most of the advantages of a MOSFET. It will get hot, but that is true of a BJT also.

    There are logic level MOSFETs designed to work with lower voltages, but generally a conventional MOSFET requires 10V or more on the gate to turn fully on. Less than that can (not will) put it in it's linear region.
     
Loading...