Quantcast SEMICONDUCTOR THEORY

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
1-5 with over a thousand volts applied to its plate whereas the maximum allowable voltage for a transistor is limited to about 200 volts (usually 50 volts or less). A tube can also handle thousands of watts of power. The maximum power output for transistor generally ranges from 30 milliwatts to slightly over 100 watts. When it comes to ruggedness and life expectancy, the tube is still in competition. Design and functional requirements usually dictate the choice of device. However, semiconductor devices are rugged and long-lived. They can be constructed to withstand extreme vibration and mechanical shock. They have been known to withstand impacts that would completely shatter an ordinary electron tube. Although some specially designed tubes render extensive service, the life expectancy of transistors is better than three to four times that of ordinary electronic tubes. There is no known failure mechanism (such as an open filament in a tube) to limit the semiconductor’s life. However, semiconductor devices do have some limitations. They are usually affected more by temperature, humidity, and radiation than tubes are. Q3.   Name three of the largest users of semiconductor devices. Q4.   State one requirement of an electron tube, which does not exist for semiconductors, that makes the tube less efficient than the semiconductor. SEMICONDUCTOR THEORY To understand why solid-state devices function as they do, we will have to examine closely the composition and nature of semiconductors. This entails theory that is fundamental to the study of solid- state devices. Rather than beginning with theory, let’s first become reacquainted with some of the basic information you studied earlier concerning matter and energy (NEETS, Module 1). ATOMIC STRUCTURE The universe, as we know it today, is divided into two parts: matter and energy. Matter, which is our main concern at this time, is anything that occupies space and has weight. Rocks, water, air, automobiles, clothing, and even our own bodies are good examples of matter. From this, we can conclude that matter may be found in any one of three states: SOLIDS, LIQUIDS, and GASES. All matter is composed of either an element or combination of elements. As you know, an element is a substance that cannot be reduced to a simpler form by chemical means. Examples of elements with which you are in contact everyday are iron, gold, silver, copper, and oxygen. At present, there are over 100 known elements of which all matter is composed. As we work our way down the size scale, we come to the atom, the smallest particle into which an element can be broken down and still retain all its original properties. The atoms of one element, however, differ from the atoms of all other elements. Since there are over 100 known elements, there must be over 100 different atoms, or a different atom for each element. Now let us consider more than one element at a time. This brings us to the term "compound." A compound is a chemical combination of two or more elements. Water, table salt, ethyl alcohol, and ammonia are all examples of compounds. The smallest part of a compound, which has all the characteristics of the compound, is the molecule. Each molecule contains some of the atoms of each of the elements forming the compound. Consider sugar, for example. Sugar in general terms is matter, since it occupies space and has weight. It is also a compound because it consists of two or more elements. Take a lump of sugar and crush


Electrical News
EEVblog #721 – Globalstar Satellite Phone Teardown
What’s inside a 2000 vintage Globalstar GSP1600 Tri-Band Satellite Phone?...
eevblog.com
Engineers Can Solve Great Problems
Today's engineering students get to see what it's like to...
eetimes.com
Qualcomm CTO on LTE-U, 5G Challenges
EE Times caught up with Matt Grob, Qualcomm CTO. We...
eetimes.com
Low-Power Wireless MCUs Proliferate
Wireless device developers now have a new range of RF...
eetimes.com
ESC Boston 2015 Sneak Peek -- Awesome Analog Meters
In this Fantastical Theatre presentation at ESC Boston 2015, Max...
eetimes.com
2D Material Beats Graphene
Black Phosphor is a 2D material with advantages over graphene,...
eetimes.com
5G Researchers Seek Spectrum
Next generation cellular communications will need to exist in current...
eetimes.com
Parrot Takes Instant 3D Mapping to the Sky
On Nvidia's booth at embedded world, a robot arm was...
eetimes.com
BlackBerry Leap Coming, But Focus Is Software
At Mobile World Congress, BlackBerry announced four smartphones, including the...
eetimes.com
IBM Slumps, Cisco Gains In 2014 Server Sales
Gartner annual report on server shipments and revenue sees Cisco,...
eetimes.com
Nvidia Gives Android a Console Play
Nvidia's Shield Console marks its latest move into the systems...
eetimes.com
FCC Chief at MWC: 'No One Blocks Internet'
FCC Chairman Tom Wheeler, at the Mobile World Congress, compared...
eetimes.com
NXP CEO: 'Security, IoT, Cars' Drove Freescale Deal
NXP CEO spoke with on the overlapping businesses with Freescale,...
eetimes.com
Spectrum, 5G in MWC Spotlight
To avoid a massive and unruly cellular frequency shakeup, a...
eetimes.com
Making MCU Software Requirements Creation Easier
To reduce labor and error in requirements definition and verification...
eetimes.com
Rohde & Schwarz highlights 5G tester at MWC
To support designers and developers in research activities, Rohde &...
eetimes.com
IoT Security a Prime Focus for Freescale
Security is a major concern in the Internet of Things,...
eetimes.com
MEMS Windmills for Energy Harvesting?
Fabricated from nickel-based alloys using MEMS techniques and processes, micro-windmills...
eetimes.com
Unleash The Power of JavaScript For IoT
Marvell has open-sourced its software crown jewel, KinomaJS. Marvell, which...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +