Chapter 5: Difference between revisions

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===NMOS Transistor===
===NMOS Transistor===
*N-channel enhancement-mode MOSFET (metal-oxide semiconductor field effect transistor)
*N-channel enhancement-mode MOSFET (metal-oxide semiconductor field effect transistor)
*The threshold voltage, <math>V_{to}</math>, is the minimum <math>V_{GS}</math> needed to move the transistor from the Cutoff to Triode region. When is reached, a channel forms beneath the gate, allowing current to flow.
:*<math>V_{to}</math> is usually on the order of a couple of volts


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*The threshold voltage, <math>V_{to}</math>, is the minimum <math>V_{GS}</math> needed to move the transistor from the Cutoff to Triode region. When is reached, a channel forms beneath the gate, allowing current to flow.
:*<math>V_{to}</math> is usually on the order of a couple of volts
*For small values of <math>V_{DS}</math>, <math>i_D</math> is proportional to <math>V_{DS}</math>. The device behaves as a resistor whose value depends on <math>v_{GS}</math>

Revision as of 22:28, 14 March 2010

NMOS Transistor

  • N-channel enhancement-mode MOSFET (metal-oxide semiconductor field effect transistor)
Nmos regions
Region VGS iD
Cutoff VGS<Vto 0
Triode VGS>Vto iDVGS
Saturation
  • The threshold voltage, Vto, is the minimum VGS needed to move the transistor from the Cutoff to Triode region. When is reached, a channel forms beneath the gate, allowing current to flow.
  • Vto is usually on the order of a couple of volts
  • For small values of VDS, iD is proportional to VDS. The device behaves as a resistor whose value depends on vGS