This document provides an introduction to JFETs (junction field effect transistors). It defines key terms like source, drain, gate, and channel. It explains that JFETs are voltage-controlled, unipolar devices and discusses n-channel and p-channel JFET operation. The document also derives the mathematical expression for pinch-off voltage and defines the ohmic, saturation, and breakdown regions of the JFET voltage-ampere characteristics.
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.
Field Effect Transistor is a transistor that is voltage controlled devices. It has higher input impedance and less sensitive to temperature variations.
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
FIELD EFFECT TRANSISTERS (FET)
Types of Field Effect Transistors
i) Junction field effect transistor (JFET)
(ii) Metal oxide semiconductor field effect transistor (MOSFET)
This presentation discusses the basics of Pass Transistor Logic, its advantages, limitation and finally implementation of Boolean functions/Combinational Logic circuits using Pass Transistor Logic.
SHORT-CHANNEL EFFECTS
A MOSFET is considered to be short when the channel length ‘L’ is the same order of magnitude as the depletion-layer widths (xdD, xdS). The potential distribution in the channel now depends upon both, transverse field Ex, due to gate bias and also on the longitudinal field Ey, due to drain bias When the Gate channel length <<1 m, short channel effect becomes important .
This leads to many
undesirable effects in MOSFET.
The short-channel effects are attributed to two physical phenomena:
A) The limitation imposed on electron drift characteristics in the channel,
B) The modification of the threshold voltage due to the shortening channel length.
In particular five different short-channel effects can be distinguished:
1. Drain-induced barrier lowering and “Punch through”
2. Surface scattering
3. Velocity saturation
4. Impact ionization
5. Hot electrons
The MOSFET is an important element in embedded system design which is used to control the loads as per the requirement. The MOSFET is a high voltage controlling device provides some key features for circuit designers in terms of their overall performance.
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.
Field Effect Transistor is a transistor that is voltage controlled devices. It has higher input impedance and less sensitive to temperature variations.
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
FIELD EFFECT TRANSISTERS (FET)
Types of Field Effect Transistors
i) Junction field effect transistor (JFET)
(ii) Metal oxide semiconductor field effect transistor (MOSFET)
This presentation discusses the basics of Pass Transistor Logic, its advantages, limitation and finally implementation of Boolean functions/Combinational Logic circuits using Pass Transistor Logic.
SHORT-CHANNEL EFFECTS
A MOSFET is considered to be short when the channel length ‘L’ is the same order of magnitude as the depletion-layer widths (xdD, xdS). The potential distribution in the channel now depends upon both, transverse field Ex, due to gate bias and also on the longitudinal field Ey, due to drain bias When the Gate channel length <<1 m, short channel effect becomes important .
This leads to many
undesirable effects in MOSFET.
The short-channel effects are attributed to two physical phenomena:
A) The limitation imposed on electron drift characteristics in the channel,
B) The modification of the threshold voltage due to the shortening channel length.
In particular five different short-channel effects can be distinguished:
1. Drain-induced barrier lowering and “Punch through”
2. Surface scattering
3. Velocity saturation
4. Impact ionization
5. Hot electrons
The MOSFET is an important element in embedded system design which is used to control the loads as per the requirement. The MOSFET is a high voltage controlling device provides some key features for circuit designers in terms of their overall performance.
A tunnel diode or Esaki diode is a type of semiconductor that is capable of very fast operation, well into the microwave frequency region, made possible by the use of the quantum mechanical effect called tunneling.
It was invented in August 1957 by Leo Esaki when he was with Tokyo Tsushin Kogyo, now known as Sony. In 1973 he received the Nobel Prize in Physics, jointly with Brian Josephson, for discovering the electron tunneling effect used in these diodes. Robert Noyce independently came up with the idea of a tunnel diode while working for William Shockley, but was discouraged from pursuing it.[1]
These diodes have a heavily doped p–n junction only some 10 nm (100 Å) wide. The heavy doping results in a broken bandgap, where conduction band electron states on the n-side are more or less aligned with valence band hole states on the p-side
Tunnel diodes were first manufactured by Sony in 1957[2] followed by General Electric and other companies from about 1960, and are still made in low volume today.[3] Tunnel diodes are usually made from germanium, but can also be made from gallium arsenide and silicon materials. They are used in frequency converters and detectors.[4] They have negative differential resistance in part of their operating range, and therefore are also used as oscillators, amplifiers, and in switching circuits using hysteresis.
Figure 6: 8–12 GHz tunnel diode amplifier, circa 1970
In 1977, the Intelsat V satellite receiver used a microstrip tunnel diode amplifier (TDA) front-end in the 14 to 15.5 GHz band. Such amplifiers were considered state-of-the-art, with better performance at high frequencies than any transistor-based front end.[5]
The highest frequency room-temperature solid-state oscillators are based on the resonant-tunneling diode (RTD).[6]
There is another type of tunnel diode called a metal–insulator–metal (MIM) diode, but present application appears restricted to research environments due to inherent sensitivities.[7] There is also a metal–insulator–insulator–metal MIIM diode which has an additional insulator layer. The additional insulator layer allows "step tunneling" for precise diode control.[8]
Basic Electronics by The Veer Surendra Sai University of TechnologyMounerSaleh1
This note explains the following topics: Signals, Linear Wave Shaping Circuits, Properties of Semiconductors, Diodes, Bipolar junction Transistor, Feedback Amplifiers and Oscillators, Field Effect Transistors, Operational Amplifiers, Digital Fundamentals, Electronic Instruments.
A p–n junction is a boundary or interface between two types of semiconductor materials, p-type ... For example, a common type of transistor, the bipolar junction transistor, consists ..... Two years later (1941), Vadim Lashkaryov reported discovery of p–n junctions in Cu2O and silver sulphide photocells and selenium rectifiers.
Similar to Introduction to Junction Field Effect Transistor (20)
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
2. Outlines
1 Introduction to FET
2 Classification of FET
3 Common Terminology in FET
4 FET Operation
5 Pinch-Off voltage
6 JFET Volt-Ampere characteristics
Dr. Varun Kumar (IIIT Surat) 2 / 16
3. Introduction to FET
Basic difference between BJT and FET
Sr no BJT FET
1 It is a bipolar device. It is a unipolar device.
2
Its operation depends
on hole and electron.
Its operation depends on
majority charge carrier.
3 It is a current controlled device. It is a voltage controlled device.
4 Input impedance is very low. Input impedance is very high.
5
It requires large physical
space for fabrication.
Small physical space
for fabrication.
Dr. Varun Kumar (IIIT Surat) 3 / 16
4. Classification of FET
1 JFET (Junction field effect transistor)
(1) n-channel
(2) p-channel
2 MOSFET (Metal oxide semiconductor field effect transistor)
(1) Depletion type MOSFET
n-channel
p-channel
(2) Enhancement type MOSFET
n-channel
p-channel
NOTE⇒ FET is a symmetrical device, irrespective of BJT.
Dr. Varun Kumar (IIIT Surat) 4 / 16
5. Common terminology
1 Source: A terminal, where majority charge carriers enter the bar.
2 Drain: A terminal, where majority charge carriers leave the bar.
3 Gate: From figure, n-type semiconductor bar has been heavily doped
on two faces with p+ material. This impurities terminals are called as
gate.
Dr. Varun Kumar (IIIT Surat) 5 / 16
6. Continued–
4 Channel: There are two types (n-channel and p-channel) of JFET.
Above figure is a n-channel JFET.
5 VGS → Gate to source voltage (VGS = −VGG = Supply voltage)
6 VDS → Drain to source voltage (VDS = VDD= Supply voltage)
7 ID → Drain current, IG → Gate current
Dr. Varun Kumar (IIIT Surat) 6 / 16
7. FET Operation
⇒ Two sides of the reverse biased p-n junction.
⇒ There are space charged regions between p-n junction.
Q What is field effect ?
Ans Current (ID) control is done by increasing the reverse bias voltage. In
other words, reverse bias creates any electric field that affect the flow
of current or conduction of the majority charge carrier.
ID = f (VGS , VDS )
Dr. Varun Kumar (IIIT Surat) 7 / 16
8. Symbol of p and n channel JFET
⇒ For n-channel JFET, ID and VDS are positive and VGS is negative.
⇒ For p-channel JFET, ID and VDS are negative and VGS is positive.
Note: The sign of arrow, shows the direction of conventional current.
Dr. Varun Kumar (IIIT Surat) 8 / 16
9. FET Characteristics
⇒ Ohmic region: The region (set of ID and VDS ), where circuit follow
the Ohm’s law or VDS = RID for any VGS
⇒ Saturation region: The drain current becomes constant for
particular VGS , irrespective of VDS .
Dr. Varun Kumar (IIIT Surat) 9 / 16
10. Continued–
⇒ Breakdown region: Self destruction of device for particular VDS is
called as breakdown region.
⇒ Pinch off region: The amount of negative VGS (in case of n-channel
JFET) for which the conduction could not be happened due to
majority charge carrier.
Dr. Varun Kumar (IIIT Surat) 10 / 16
11. Pinch off voltage Vp
⇒ It is a gate to source voltage in reverse bias condition, so that no
conduction or ID ≈ 0 could be possible.
⇒ This analysis was first made by Shockley.
⇒ A n-type semiconductor is sandwiched between two layers of p-type
material forming two p-n junction.
⇒ p-type region is doped with NA acceptor per cubic meter.
⇒ n-type region is doped with ND acceptor per cubic meter.
⇒ W = Wn + Wp → Total space charge width.
Wp → Space charge width due to hole.
Wn → Space charge width due to electron.
⇒ If NA >> ND then Wp << Wn. Hence Wn(x) = W (x) at a distance
x along the channel
Dr. Varun Kumar (IIIT Surat) 11 / 16
12. Mathematical expression for pinch off voltage
W (x) = a − b(x) =
n 2
qND
(V0 − V (x))
o1/2
(1)
♦ = Dielectric constant of channel material
♦ q = Magnitude of electronic charge
♦ V0 = Junction contact potential at x.
Dr. Varun Kumar (IIIT Surat) 12 / 16
13. When ID = 0
♦ V (x)= Applied potential across space-charge region at x and is a
negative number for an applied reverse bias.
♦ a − b(x)= Penetration W (x) of depletion region into channel at a
point x along channel.
♦ Note: If drain current is zero, i.e. ID = 0, b(x) and V (x) are
independent of x. Hence, b(x) = b
♦ If we substitute b(x) = b = 0 and solve for V on the assumption
V0 |V |. We obtain the pinch-off voltage Vp. Hence,
|Vp| =
qND
2
a2
(2)
Note: If we substitute VGS = V0 − V (x)
VGS =
1 −
b
a
2
Vp (3)
Dr. Varun Kumar (IIIT Surat) 13 / 16
14. Example
Q For an n-channel silicon FET with a = 3 × 10−4cm and
ND = 1015electrons/cm3. Find
(a) Pinch-off voltage
(b) The channel half width for VGS = 1
2 Vp and ID = 0
Hint: = r 0, r → Silicon=12
Dr. Varun Kumar (IIIT Surat) 14 / 16
15. JFET VOLT-AMPERE Characteristics
⇒ Now, small VDS is applied between drain and source.
⇒ Small ID will flow from drain to source.
⇒ The effective channel cross section area = A = 2bw.
⇒ 2b = Channel width corresponding to zero drain current.
⇒ w = Channel dimension perpendicular to the b direction.
⇒ Using Ohm’s law, no current flows in the depletion region. Hence the
drain current
ID = AqNDµnζ = 2bwqNDµn
VDS
L
(4)
L is the length of the channel.
Dr. Varun Kumar (IIIT Surat) 15 / 16
16. Continued–
Substituting b from (3) in (4), we have for small ID,
ID =
2awqNDµn
L
h
1 −
VGS
Vp
1/2i
VDS (5)
⇒ Above expression shows the volt ampere characteristics for small VDS .
⇒ For small VDS , JFET behaves like an ohmic resistance whose value is
determined by VGS .
⇒ The ration VDS
ID
at the origin is called the ON drain resistance rd,ON.
At VGS = 0
rd,ON =
L
2awqNDµn
(6)
Dr. Varun Kumar (IIIT Surat) 16 / 16
