finals-JFET Flashcards
is a 3 terminal semiconductor device in which current conducted by one type of carrier i.e. by electron or hole.
JFET
4 main Parts of JFET Device
1) Source
2) Drain
3) Gate
4) Channel
terminal which majority carriers enter into the channel is called ________ terminal __
Source, S
terminal which majority carriers leave from the channel is called ________ terminal __
Drain, D
There are two internally connected heavily-doped impurity regions to create two P-N junctions. These impurity regions are called the _______ terminal __
Gate, G
The region between the source and drain, sandwiched between the two gates is called the ________
Channel
in JFET, n-type region between the p regions offers a _________________
resistance to current flow
in JFET, the resistance varies with the voltage applied to ___________
gate terminal VG
FET has 3 terminals:
Basic Operation of JFET
Gate (G), Drain (D) and Source (S)
in n-channel FET, ____ and ____ are connected to n-channel and ____ is connected to the p-type material
Basic Operation of JFET
Drain and Source, Gate
The voltage applied at gate terminal controls the current flow between the other two terminals;
Basic Operation of JFET
Source and Drain
it can be thought of as a resistance connected between Source and Drain, which is a function of the gate voltage VG
Basic Operation of JFET
FET
varies in different types of FETs
Basic Operation of JFET
mechanism of gate control
in operation of JFET, a reverse voltage is applied to the:
Basic Operation of JFET
Gate and Forward voltage between Drain and Source
2 Basic Operation of JFET:
1) VG=0V and VDS=0V
2) VG=0V and VDS is +ve
There occurs a ________ at the p-n junction as the electrons from n-channel combine with holes from p-gate
Basic Operation of JFET
depletion region
since no voltages are applied, the depletion regions are of:
Basic Operation of JFET
equal thickness and symmetrical
is zero as VD is 0V wrt source
Basic Operation of JFET
Drain current ID
VG=0V and VDS is increased from 0 to a more:
Basic Operation of JFET
positive voltage
the depletion region between p-gate and n-channel ____ as more electrons from n-channel combine with holes from p-gate
Basic Operation of JFET
increases
increasing the depletion region;
Basic Operation of JFET
1) decreases - size of n-channel which;
2) increases - resistance of the n-channel
Though the resistance of the channel increases with increasing VDS, the ____ doesn’t decrease, rather it increases because drain voltage wet source increases
Basic Operation of JFET
current ID
being larger at the drain end than at the source end
Basic Operation of JFET
wedge shaped depletion regions
it is the curve between drain current (ID) and drain-source voltage (VDS) for different gate-source voltage (VGS)
JFET
IV Characteristic Curve