Field Effect Transistor is a transistor that is voltage controlled devices. It has higher input impedance and less sensitive to temperature variations.
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET). It has an insulated gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. Although FET is sometimes used when referring to MOSFET devices, other types of field-effect transistors also exist.
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET). It has an insulated gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. Although FET is sometimes used when referring to MOSFET devices, other types of field-effect transistors also exist.
Mosfet
MOSFETs have characteristics similar to JFETs and additional characteristics that make them very useful.
There are 2 types:
• Depletion-Type MOSFET
• Enhancement-Type MOSFET
1)What is BJT?
2)What is the history of its invention?
3) Physical structure of BJT
4)BJT symbol
5)BJT operations
6)Application of BJT: i) As a switch & ii)As an amplifier
7)Other uses of BJT
8)BJT vs MOSFET
FIELD EFFECT TRANSISTERS (FET)
Types of Field Effect Transistors
i) Junction field effect transistor (JFET)
(ii) Metal oxide semiconductor field effect transistor (MOSFET)
A Zener diode is a type of diode that permits current not only in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger than the breakdown voltage known as “Zener knee voltage” or “Zener voltage”.
The device is named after American physicist Clarence Melvin Zener, who first described the ZENER EFFECT in1934. Later his work led to the BELL LABS implantation of the effect in form of an electronic device, the ZENER DIODE.
Zener diodes are a modified form of PN silicon diode used extensively for voltage regulation. The P type and N type silicon used is doped more heavily than a standard PN diode.
This causes a very thin depletion region. The zener diodes breakdown characteristics are determined by the doping process
Zeners are commercially available with voltage breakdowns of 1.8 V to 200 V.
When a Zener diode is forward biased, it operates as a normal diode.
In forward biased P side connected to positive and N side connected to negative terminal of battery. In this case the electrons and holes are swept across the junction and large current flow through it.
In case of reverse biased current practically zero and at certain voltage which called Zener voltage the current increases sharply.
Each Zener diode has breakdown rating which specifies the max voltage that can be dropped across it.
Zener diodes are designed to operate in reverse breakdown. Two types of reverse breakdown in a zener diode are AVALANCHE and ZENER. The avalanche break down occurs in both rectifier and zener diodes at a sufficiently high reverse voltage. Zener breakdown occurs in a zener diode at low reverse voltages.
A Zener allows current to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "Zener knee voltage", "Zener voltage", “Avalanche point", or “Peak inverse voltage”
Breakdown Characteristics : Figure 2 shows the reverse portion of a zener diode’s characteristic curve. As the reverse voltage (푉_푅 ) is increased, the reverse current (퐼_푅 ) remains extremely small up to the “knee” of the curve. The reverse current is also called the zener current, 퐼_푍 . At this point, the breakdown effect begins; the internal zener resistance, also called zener impedance (푍_푍), begins to decrease as reverse current increases rapidly.Voltage Regulator :In a DC circuit, Zener diode can be used as a voltage regulator to regulate the voltage across small circuits.
Waveform Clipper :Zener diode can be used to make a Waveform Clipper. Two Zener diodes facing each other in series will act to clip both halves of an input signal.
Voltage Shifter :A Zener diode can be applied to a circuit with a resistor to act as a voltage shifter. This circuit lowers the output voltage by a quantity that is equal to the Zener diode's breakdown voltage.
Pn junction diode by sarmad baloch
I AM SARMAD KHOSA
BSIT (5TH A)
(ISP)
FACEBOOK PAGLE::
https://www.facebook.com/LAUGHINGHLAUGHTER/
YOUTUBE CHANNEL:::
https://www.youtube.com/channel/UCUjaIeS-DHI9xv-ZnBpx2hQ
Mosfet
MOSFETs have characteristics similar to JFETs and additional characteristics that make them very useful.
There are 2 types:
• Depletion-Type MOSFET
• Enhancement-Type MOSFET
1)What is BJT?
2)What is the history of its invention?
3) Physical structure of BJT
4)BJT symbol
5)BJT operations
6)Application of BJT: i) As a switch & ii)As an amplifier
7)Other uses of BJT
8)BJT vs MOSFET
FIELD EFFECT TRANSISTERS (FET)
Types of Field Effect Transistors
i) Junction field effect transistor (JFET)
(ii) Metal oxide semiconductor field effect transistor (MOSFET)
A Zener diode is a type of diode that permits current not only in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger than the breakdown voltage known as “Zener knee voltage” or “Zener voltage”.
The device is named after American physicist Clarence Melvin Zener, who first described the ZENER EFFECT in1934. Later his work led to the BELL LABS implantation of the effect in form of an electronic device, the ZENER DIODE.
Zener diodes are a modified form of PN silicon diode used extensively for voltage regulation. The P type and N type silicon used is doped more heavily than a standard PN diode.
This causes a very thin depletion region. The zener diodes breakdown characteristics are determined by the doping process
Zeners are commercially available with voltage breakdowns of 1.8 V to 200 V.
When a Zener diode is forward biased, it operates as a normal diode.
In forward biased P side connected to positive and N side connected to negative terminal of battery. In this case the electrons and holes are swept across the junction and large current flow through it.
In case of reverse biased current practically zero and at certain voltage which called Zener voltage the current increases sharply.
Each Zener diode has breakdown rating which specifies the max voltage that can be dropped across it.
Zener diodes are designed to operate in reverse breakdown. Two types of reverse breakdown in a zener diode are AVALANCHE and ZENER. The avalanche break down occurs in both rectifier and zener diodes at a sufficiently high reverse voltage. Zener breakdown occurs in a zener diode at low reverse voltages.
A Zener allows current to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "Zener knee voltage", "Zener voltage", “Avalanche point", or “Peak inverse voltage”
Breakdown Characteristics : Figure 2 shows the reverse portion of a zener diode’s characteristic curve. As the reverse voltage (푉_푅 ) is increased, the reverse current (퐼_푅 ) remains extremely small up to the “knee” of the curve. The reverse current is also called the zener current, 퐼_푍 . At this point, the breakdown effect begins; the internal zener resistance, also called zener impedance (푍_푍), begins to decrease as reverse current increases rapidly.Voltage Regulator :In a DC circuit, Zener diode can be used as a voltage regulator to regulate the voltage across small circuits.
Waveform Clipper :Zener diode can be used to make a Waveform Clipper. Two Zener diodes facing each other in series will act to clip both halves of an input signal.
Voltage Shifter :A Zener diode can be applied to a circuit with a resistor to act as a voltage shifter. This circuit lowers the output voltage by a quantity that is equal to the Zener diode's breakdown voltage.
Pn junction diode by sarmad baloch
I AM SARMAD KHOSA
BSIT (5TH A)
(ISP)
FACEBOOK PAGLE::
https://www.facebook.com/LAUGHINGHLAUGHTER/
YOUTUBE CHANNEL:::
https://www.youtube.com/channel/UCUjaIeS-DHI9xv-ZnBpx2hQ
The three terminals of the FET are known as Gate, Drain, and Source.
It is a voltage controlled device, where the input voltage controls by the output current.
In FET current used to flow between the drain and the source terminal. And this current can be controlled by applying the voltage between the gate and the source terminal.
So this applied voltage generate the electric field within the device and by controlling these electric field we can control the flow of current through the device.
This presentation is for beginners of electronics. This will give you a brief about all the important basic building blocks of electronics and hence will be helpful in creating a good foundation.
Field-effect transistor amplifiers provide an excellent voltage gain with the added feature of high input impedance. They are also low-power-consumption configurations with good frequency range and minimal size and weight.
JFETs, depletion MOSFETs, and MESFETs can be used to design amplifiers having similar voltage gains.
The depletion MOSFET (MESFET) circuit, however, has a much higher input impedance than a similar JFET configuration.
Bipolar Junction Transistor (BJT) DC and AC AnalysisJess Rangcasajo
BJT AC and DC Analysis
This slide condenses the two ways analysis of BJT (AC and DC).
At the end of the slide, it has review question answer with answer key as providing.
Field Effect Transistor Biasing and ConfigurationJess Rangcasajo
Field Effect Transistor Biasing and Configuration
It provides the simplest configuration in understanding the FET. In this slide, it's only described and elaborate the Basic Current Relationship of FET.
Diodes and its application encapsulate the different characteristics of different type of diodes. Also, define its different biases and how it works.
It provides shortcut method in analyzing Clamper and clipper.
At the end of the powerpoint, there has a review question to answer with answer key provided.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
It consists of cw radar and fmcw radar ,range measurement,if amplifier and fmcw altimeterThe CW radar operates using continuous wave transmission, while the FMCW radar employs frequency-modulated continuous wave technology. Range measurement is a crucial aspect of radar systems, providing information about the distance to a target. The IF amplifier plays a key role in signal processing, amplifying intermediate frequency signals for further analysis. The FMCW altimeter utilizes frequency-modulated continuous wave technology to accurately measure altitude above a reference point.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
7. CONSTRUCTION AND CHARACTERISTICS OF
JFET
Is a three-terminal device with one terminal capable
of controlling the current between the other two.
3 terminals are:
1. DRAIN (D)
2. SOURCE (S) – connected to n-channel
3. GATE (G) – connected to p-channel
8. Two types of JFET
1.n-channel
2.p-channel
Note:
n-channel is more widely used.
Drain
Gate
Source
Drain
Gate
Source
13. JFET is always operated with the gate-source PN
junction reversed biased.
Reverse biasing of the gate source junction with the
negative voltage produces a depletion region along the
PN junction which extends into the n-channel and thus
increases its resistance by restricting the channel width
as shown in the preceding figure.
14. 𝑽 𝑮𝑺 = 𝟎, 𝑽 𝑫𝑺 SOME POSITIVE VALUE
When 𝐕 𝐆𝐒 = 𝟎 𝐚𝐧𝐝 𝐕 𝐃𝐒 is increased from
0 to a more positive voltage.
The depletion region between p-gate
and n-channel increases
Increasing the depletion region,
decreases the size of the n-channel
which increases the resistance of the
n-channel.
Even though the n-channel resistance
is increasing, the current (ID) from
source to drain through the n-channel
is increasing. This is because VDS is
increasing.
Recall from DIODE discussion:
- The greater the applied reverse bias, the wider is the depletion region.
IG = 0
15.
16. REGIONS OF JFET ACTION
1. Ohmic Region – linear region
JFET behaves like an ordinary resistor
2. Pinch Off Region
Saturation or Amplifier Region
JFET operates as a constant current device because Id
is relatively independent of Vds
Idss – drain current with gate shorted to source.
3. Breakdown Region
If Vds is increased beyond its value corresponding to Va
– avalanche breakdown voltage.
JFET enters the breakdown region where Id increases to
an excessive value.
17. 4. Cut Off Region
As Vgs is made more and more negative, the gate
reverse bias increases which increases the thickness
of the depletion region.
As negative value of Vgs is increased, a stage comes
when the 2 depletion regions touch each other.
Vgs (off) = -Vp
/Vp/ = /Vgsoff/
18.
19. JFET OPERATING CHARACTERISTICS: PINCH OFF
If VGS = 0 and VDS is further
increased to a more positive
voltage, then the depletion zone
gets so large that it pinches off the
n-channel.
As VDS is increased beyond |VP |,
the level of ID remains the same
(ID= IDSS)
20. 𝑽 𝑮𝑺 ≥ 𝟎
Voltage from gate to source is controlling
voltage of the JFET.
As 𝐕 𝐆𝐒 becomes more negative, the
depletion region increases.
The more negative 𝐕 𝐆𝐒, the
resulting level for 𝐈 𝐃 is reduced.
Eventually, when 𝐕 𝐆𝐒 = 𝐕𝐩 [Vp = VGS
(off)], ID is 0 mA. (the device is
“turned off”.
22. JFET OPERATING CHARACTERISTICS: VOLTAGE-
CONTROLLED RESISTOR
The region to the left of the
pinch-off point is called the
ohmic region/Voltage controlled
resistance region.
The JFET can be used as a variable resistor, where VGS controls the drain-
source resistance (rd). As VGS becomes more negative, the resistance (rd)
increases
23. where ro is the resistance with VGS=0 and rd is the
resistance at a particular level of VGS.
24. 1. For an n-channel JFET with 𝑟𝑜 = 10𝑘Ω 𝑉𝐺𝑆 =
FOR EXAMPLE:
𝑟𝑑 =
10𝑘Ω
(1 −
−3
−6
)2
𝑟𝑑 = 40𝑘Ω
25. P-CHANNEL JFETS
The p-channel JFET
behaves the same as the
n-channel JFET, except the
voltage polarities and
current directions are
reversed.
26. P-CHANNEL JFET CHARACTERISTICS
Also note that at high levels of VDS
the JFET reaches a breakdown
situation: ID increases uncontrollably
if VDS > VDSmax
29. 𝐼 𝐷 is between 0 A and 𝐼 𝐷𝑆𝑆 𝑓𝑜𝑟 𝑉𝐺𝑆 ≤
0𝑉 𝑎𝑛𝑑 𝑔𝑟𝑒𝑎𝑡𝑒𝑟 𝑡ℎ𝑎𝑛 𝑡ℎ𝑒 𝑝𝑖𝑐𝑛ℎ 𝑜𝑓𝑓 𝑙𝑒𝑣𝑒𝑙.
30. JFET TRANSFER CHARACTERISTICS
In a BJT, 𝛽 indicates the relationship between 𝐼 𝐵 (input) and 𝐼 𝐶 (output).
𝐼 𝐶 = 𝑓 𝐼 𝐵 = 𝛽𝐼 𝑏
Constant
Control variable
In a JFET, the relationship of 𝑉𝐺𝑆 (input) and 𝐼 𝐷 (output) is defined by
Shockley’s Equation
𝐼 𝐷 = 𝐼 𝐷𝑆𝑆 1 −
𝑉𝐺𝑆
𝑉𝑝
2
Constant
Control variable
33. PLOTTING THE JFET TRANSFER CURVE
Using 𝐼 𝐷𝑆𝑆 and 𝑉𝑝 (𝑉𝐺𝑆(𝑜𝑓𝑓)) values found in a specification sheet, the transfer
curve can be plotted according to these three steps:
Step 1:
Solving for 𝑉𝐺𝑆 = 0, 𝐼 𝐷 = 𝐼 𝐷𝑆𝑆 1 −
𝑉𝐺𝑆
𝑉𝑝
2
, ID = IDSS
Step 2:
Solving for 𝑉𝐺𝑆 = 𝑉𝑝(𝑉𝐺𝑆 𝑜𝑓𝑓 ), 𝐼 𝐷 = 𝐼 𝐷𝑆𝑆 1 −
𝑉𝐺𝑆
𝑉𝑝
2
, ID = 0 A
Step 3:
Solving for 𝐼 𝐷 if we substitute 𝑉𝐺𝑆 = −1 𝑉 , 𝐼 𝐷𝑆𝑆 = 8mA and 𝑉𝑝 =-4
𝐼 𝐷 = 𝐼 𝐷𝑆𝑆 1 −
𝑉𝐺𝑆
𝑉𝑝
2
, 𝐼 𝐷 = 8𝑚𝐴 1 −
(−1)
(−4)
2
,
ID = 4.5mA
38. THERE ARE TWO TYPES OF MOSFETS:
Depletion-Type
Enhancement-Type
39. DEPLETION-TYPE MOSFET CONSTRUCTION
The Drain (D) and Source (S)
connect to the to n-doped regions.
These n-doped regions are
connected via an n-channel.
This n-channel is connected to the
Gate (G) via a thin insulating layer
of SiO2.
The n-doped material lies on a p-
doped substrate that may have an
additional terminal connection
called Substrate (SS).
n-Channel depletion-type
MOSFET
Dielectric
insulator
40. SILICON DIOXIDE:
Insulator refer to as DIELECTRIC.
It sets up opposing electric field within the dielectric
when exposed to an externally applied field.
The fact that SiO2 layer is an insulating layer
means that:
There is no direct electrical connection between the
gate terminal and the channel of a MOSFET.
It is the insulating layer of SiO2 in the MOSFET
construction that accounts for the very desirable high
input impedance of the device
41. WHY MOSFET?
Metal:
For the drain, source, and gate connection for the proper
surface – in particular, the gate terminal and the control to be
offered by the surface area of the contact.
Oxide:
For the Silicon dioxide insulating layer.
Semiconductor:
For the basic structure on which the n- and p-type region are
DIFFUSED.
MOSFET is also called
INSULATED GATE-FET or IGFET
42. DEPLETION-TYPE MOSFET :BASIC OPERATION
AND CHARACTERISTICS
VGS = 0 and VDS is applied
across the drain to source
terminals.
This results to attraction of
free electrons of the n-
channel to the drain, and
hence current flows.
43. Continuation….
𝑉𝐺𝑆 is set at a negative
voltage such as -1 V
The negative potential at the
gate pressure electrons
toward the p-type substrate
and attract the holes for the
p-type substrate.
This will reduce the number
of free electrons in the n-
channel available for
conduction.
The more negative the 𝑉𝐺𝑆 ,
the resulting level of drain
current 𝐼 𝐷 is reduced.
When 𝑉𝐺𝑆 is reduced to 𝑉𝑃
(pinch off voltage), then 𝐼 𝐷 =
0𝑚𝐴.
44. When 𝑉𝐺𝑆 is reduced to 𝑉𝑃 (pinch off) {i.e 𝑉𝑃 = −6𝑉} then 𝐼 𝐷 = 0𝑚𝐴.
For positive values of 𝑉𝐺𝑆, the positive gate will draw additional
electrons (free carriers from the p-type substarte and hence 𝐼 𝐷
increases.)
50. ENHANCEMENT-TYPE MOSFET CONSTRUCTION
The Drain (D) and Source (S)
connect to the to n-doped
regions.
The Gate (G) connects to the
p-doped substrate via a thin
insulating layer of SiO2
There is no channel
The n-doped material lies on
a p-doped substrate that may
have an additional terminal
connection
51. For 𝑉𝐺𝑆 = 0, 𝐼 𝐷 = 0(no channel)
For 𝑉𝐷𝑆 some positive voltage
and 𝑉𝐺𝑆 = 0, two reversed biased
n-junctions and no significant
flow between drain and source.
For 𝑉𝐺𝑆 > 0 and 𝑉𝐺𝑆 > 0, the
positive voltage at gate pressure
holes to enter deeper regions of
the p-substrate, and the electrons
in p-substrate and the electrons
in p-substrate will be attracted to
the positive gate.
The level of 𝑉𝐺𝑆 that results in the
significant increase in drain
current in called:
THRESHOLD VOLTAGE (Vt)
For 𝑉𝐺𝑆 < 𝑉𝑇, 𝐼 𝐷 = 0𝑚𝑎
52. BASIC OPERATION OF THE E-TYPE MOSFETNote:
The enhancement-type
MOSFET operates only in the
enhancement mode
𝑉𝐺𝑆 is always positive
As 𝑉𝐺𝑆 increases, 𝐼 𝐷 increases
As 𝑉𝐺𝑆 is kept constant and 𝑉𝐷𝑆 is
increased, then 𝐼 𝐷 saturates (𝐼 𝐷𝑆𝑆)
and the saturation level, 𝑉𝐷𝑆𝑠𝑎𝑡 is
reached.
𝑉𝐷𝑆𝑠𝑎𝑡 can be calculated by
𝑉𝐷𝑠𝑎𝑡 = 𝑉𝐺𝑆 − 𝑉𝑇
53. E-TYPE MOSFET TRANSFER CURVE
To determine 𝐼 𝐷 given 𝑉𝐺𝑆:
Where,
𝑉𝑇 is the threshold voltage or voltage at which the MOSFET turns on.
𝑘, a constant, can be determined by using values at a specific point and the
formula:
54. FOR EXAMPLE:
Substituting 𝐼 𝐷(𝑜𝑛) = 10𝑚𝐴 𝑤ℎ𝑒𝑛 𝑉𝐺𝑆(𝑜𝑛) = 8𝑉
The level of 𝑉𝑇 is 2V, as revealed by
the fact that the drain current has
dropped to 0 mA.
𝑘 =
10𝑚𝐴
(8𝑉 − 2𝑉)2
= 𝟎. 𝟐𝟕𝟖𝒙𝟏𝟎−𝟑 𝑨
𝑽 𝟐
55. Note:
For values of 𝑉𝐺𝑆 less than the threshold level, the drain current of an
enhancement type MOSFET is 0 mA.
Substituting the 𝑉𝐺𝑆 from the general equation:
𝐼 𝐷 = 𝑘(𝑉𝐺𝑆 − 𝑉𝑇)2
𝑘 = 0.278𝑥10−3
𝐼 𝐷 = 0.278𝑚𝐴/𝑉2
(𝑉𝐺𝑆 − 2𝑉)2
i.e substituting 𝑉𝐺𝑆 = 4𝑉, we find that
𝐼 𝐷 = 0.278𝑚𝐴/𝑉2(4𝑉 − 2𝑉)2
𝑰 𝑫 = 𝟏. 𝟏𝟏𝒎𝑨
58. VMOS CHARACTERISTICS:
Compared with commercially available planar
MOSFETs, VMOS FETs have reduced channel
resistance levels and higher current and power
ratings
VMOS FETs have a positive temperature
coefficient that will combat the possibility of
thermal runaway
The reduced charge storage levels result in faster
switching times for VMOS construction compared
to those for conventional planar construction
62. ASSIGNMENT:
1. In what ways is the construction of a depletion type
of MOSFET similar to that of a JFET? In what ways is
it different?
2. What is the significant difference between the
construction of an enhancement type MOSFET and a
depletion type MOSFET?
3. Sketch the transfer characteristics of a p-channel
enhancement type MOSFET if 𝑉𝑇 = −5𝑉 and 𝑘 =
0.45𝑥10−3 𝐴 𝑉2.