Quantcast Figure 3-2B.-Energy diagram for Zener diode

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-4 energy difference across this gap determines whether a solid material will act as a conductor, a semiconductor, or an insulator. A conductor is a material in which the forbidden gap is so narrow that it can be considered nonexistent. A semiconductor is a solid that contains a forbidden gap, as shown in figure 3-2, view A. Normally, a semiconductor has no electrons at the conduction band energy level. The energy provided by room temperature heat, however, is enough energy to overcome the binding force of a few valence electrons and to elevate them to the conduction band energy level. The addition of impurities to the semiconductor material increases both the number of free electrons in the conduction band and the number of electrons in the valence band that can be elevated to the conduction band. Insulators are materials in which the forbidden gap is so large that practically no electrons can be given enough energy to cross the gap. Therefore, unless extremely large amounts of heat energy are available, these materials will not conduct electricity. View B of figure 3-2 is an energy diagram of a reverse-biased Zener diode. The energy bands of the P and N materials are naturally at different levels, but reverse bias causes the valence band of the P material to overlap the energy level of the conduction band in the N material. Under this condition, the valence electrons of the P material can cross the extremely thin junction region at the overlap point without acquiring any additional energy. This action is called tunneling. When the breakdown point of the PN junction is reached, large numbers of minority carriers "tunnel" across the junction to form the current that occurs at breakdown. The tunneling phenomenon only takes place in heavily doped diodes such as Zener diodes. Figure 3-2B.-Energy diagram for Zener diode. The second theory of reverse breakdown effect in diodes is known as AVALANCHE breakdown and occurs at reverse voltages beyond 5 volts. This type of breakdown diode has a depletion region that is deliberately made narrower than the depletion region in the normal PN-junction diode, but thicker than that in the Zener-effect diode. The thicker depletion region is achieved by decreasing the doping level from the level used in Zener-effect diodes. The breakdown is at a higher voltage because of the higher


Electrical News
Friday Quiz: Units of Measurement
The ways we express units of measurement should be perfectly...
eetimes.com
Nvidia's Maxwell Lights Up Voxels
Nvidia's Maxwell, its new high-end graphics processor, opens up a...
eetimes.com
Backlash Coming on Car-to-Car Talk?
Vehicle-to-vehicle communications will be mandated in the US, but public...
eetimes.com
Training Opportunities Abound at ARM TechCon
ARM TechCon is only a few weeks away, and if...
eetimes.com
10 Top Video Parodies on User Interfaces
There have been some interesting videos of "user interface parodies"...
eetimes.com
Making Wearables Personal
Wearables should be as unique as the person who wears...
blog.designersofthings.com
Elastomeric Camouflage Switches Texture & Color
Inspired by nature's most skillful camouflage artists, MIT researchers harness...
eetimes.com
Infographic: A History of Wearable Tech
Take a stroll down wearable memory lane in this great...
blog.designersofthings.com
18 Views of the Silicon Horizon
Semiconductors are poised for high single-digit growth this year and...
eetimes.com
Power Week: Did We Just Avoid an 'Electric Armageddon?'
While a powerful solar storm this past week resulted only...
eetimes.com
Rube Goldberg Rocket Launch
For their first real-world project, a group of budding young...
eetimes.com
Makers, Engineers Mix at NY Event
Educators and engineers from across the country attended New York's...
eetimes.com
Interview with Rod Elliott from Elliott Sound Products
Meet Rod Elliott the man behind the famous sound.westhost.com audio...
eevblog.com
Boeing, SpaceX Take US Back to Space Station
NASA taps Boeing Co., the safe but expensive choice, and...
eetimes.com
Technology You Can Sink Your Teeth Into
Thanks to 3D imaging software and a special milling machine,...
eetimes.com
Does Reducing Power Consumption Actually Save Energy?
It's the law of unintended consequences again, as regulations to...
eetimes.com
Local Motors Succeeds in Test Driving First 3D-Printed Car
3D-printed car has successful test drive!...
eetimes.com
Designer of Things Keynote Speaker: Gadi Amit
EETimes is pleased to announce that Gadi Amit will be...
eetimes.com
Sensor Hubs Aided by IEEE-2700-2014 Datasheets
The first MEMS standard, the IEEE 2700-2014, will standardize data...
eetimes.com
Dr. Duino Diagnostic Shield Deduces Dilemmas in Arduino Shield Stacks
When sandwiched an Arduino Uno and a shield -- or...
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 +