D-MOSFET Flashcards
MOSFET
Metal Oxide Semiconductor Field Effect Transistor
is a type of Field Effect Transistor and it is a voltage-controlled device.
MOSFET
MOSFET is also called?
Insulated Gate Field Effect Transistor (IGFET)
used for switching or amplifying electronic
signals in electronic devices.
MOSFET
most commonly used transistor and it can
be used in both analog and digital circuits.
MOSFET
MOSFET is a four-terminal device with a:
1) Drain (D),
2) Source (S),
3) Gate (G),
4) Body (B)/Substrate (SS)
The body terminal will always be connected to the ________ terminal hence, the MOSFET will operate as a ____________device
Source, three-terminal
D-MOSFET
Depletion Mode - Metal Oxide Semiconductor Field Effect Transistor
The ________-type MOSFET has characteristics similar to those of a JFET between ________ and ________ i.e between VGS=0 to VGS=VGSoff and it also has the added feature of characteristics to extend beyond __________.
depletion, cutoff and saturation, saturation
In JFET for its operation, the Gate to Source voltage VGS should always be ________ biased and Drain to Source voltage VDS should be ________ biased. In MOSFET, the voltage VGS can be reverse or forward biased.
Depletion-type MOSFET
reverse, forward
When reverse biased it just act similar to JFET and the MOSFET is said to be working in ________ mode. When VGS is forward biased, ________________ than the IDSS flows through it and the MOSFET is said to be in ____________ mode.
Depletion-type MOSFET
depletion, higher current, enhancement
____________________ can operate in both depletion and enhancement mode. Where as enhancement-type MOSFET is operated only_________________
Depletion-type MOSFET, enhancement mode
is used as the foundation on which the device is constructed.
N-Channel D-MOSFET Construction
p-type substrate
Two n+-doped regions linked by an n-channel lies on a ________________
N-Channel D-MOSFET Construction
p-doped substrate
The________ and ________ terminals are connected through metallic contacts to the n-doped regions.
N-Channel D-MOSFET Construction
Drain (D) and Source (S)
The substrate is either internally connected or taken out as an additional terminal labeled ____ resulting in ______ terminal device.
N-Channel D-MOSFET Construction
SS, four
The gate is insulated from the n-channel by a very thin layer of ________________ and a gate terminal is taken out through metallic contact.
N-Channel D-MOSFET Construction
silicon dioxide (SiO2)
act as an insulator which sets up opposing electric fields within the dielectric when an external field is applied.
N-Channel D-MOSFET Construction
SiO2 layer
Due to SiO2 insulating layer, there is no ________________________ between the gate and channel which accounts for very high input impedance of MOSFET
N-Channel D-MOSFET Construction
direct electrical connection
When VGS=0 and VDS is applied across ________________ terminals, the free elctrons enters from the ________ get attracted towards positive terminal through ____________ and a current flow similar to that through the channel of JFET
N-Channel D-MOSFET Construction (Basic Operation)
drain to source, source, n-channel
When a negative voltage VGS is applied, it repels electrons towards the p-type substrate and attracts holes from it, causing ____________. This reduces the number of free electrons in the channel, decreasing the __________.
N-Channel D-MOSFET Construction (Basic Operation)
recombination, current flow
more ________, the higher is the rate of recombination and therefore lesser is the flow of ___________.
N-Channel D-MOSFET Construction (Basic Operation)
negative bias, drain current
When VGS=>VGSoff, all the free electrons get recombined with ________, the channel becomes depleted of ________________, the pinch-off occurs and hence ____________________.
N-Channel D-MOSFET Construction (Basic Operation)
holes, charge carriers, no current flows
When a ________ voltage VGS is applied, the gate will draw additional free electrons from the p-substrate due to the ________________ and establish new carriers through the ________. As the VGS continues to increase in the postive direction, the ____________ is increased at a rapid rate.
N-Channel D-MOSFET Construction (Basic Operation)
positive, reverse leakage current, collisions, drain current
thus, the application of positive voltages VGS, _________ the level of free carriers in the channel compared to that encountered with VGS=0V.
N-Channel D-MOSFET Construction (Basic Operation)
enhance
For this reason, in the region of ________________________, the MOSFET is said to be operating in enhancement mode whereas in the region of VGS=0 and negative VGS, the MOSFET is said to be operating in ____________.
positive gate-to-source voltage, depletion mode
The ____________________is applicable for the depletion type MOSFET characteristics in both the ____________ and ________________ region.
Shockley’s equation, depletion and enhancement
The p-channel Depletion MOSFET is similar to the n-channel except that the voltage polarities and current directions are ________.
P-Channel D-MOSFET Construction
reversed
