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
Can You Trust a DR-Check Without a DR-Spec?
Designers may find the flow from the design rule specification...
eetimes.com
SoC From Russia With MIPS
Baikal Electronics of Russia, announced its T1, the first chip...
eetimes.com
Satisfy the Appetite for "Instant On"
Memory has emerged as a key differentiator in how embedded...
eetimes.com
On Control-S
That nervous twitch of the left hand to save files...
eetimes.com
IoT Security Groundswell Gathers
After plenty of talk, a wave of real action aimed...
eetimes.com
CES Asia: 'Zero Distance' to Supply Chains
Conspicuously missing from CES Asia are big name consumer electronics...
eetimes.com
eevBLAB #10 – Why Learn Basic Electronics?
A reddit user asks what is the point in learning...
eevblog.com
Spreadtrum Guns for Intel's 14nm FinFET in 2016
Working with Intel, Spreadtrum CEO Leo Li sees three things...
eetimes.com
Sensor Choices Power Industrial Internet Innovation
Whether or not the Internet of Things will live up...
eetimes.com
Implanted Biosensor Can Be Wirelessly Charged
A laboratory at the Ecole Polytechnique Federale de Lausanne has...
eetimes.com
Altium's Free PCB Tool Available for Test and Evaluation
Looking to attract would-be electronic designers in the DIY maker,...
eetimes.com
Do You Have a Whey With Curds?
In addition to cows, sheep, and goats -- cheese can...
eetimes.com
Smartening up Power Monitoring
Built around an internal 16-bit PIC MCU, Microchip's new power...
eetimes.com
Waving the Flag
Economic espionage in the electronics industry is really the issue?...
eetimes.com
Xiaomi's Spending Spree: Its Logic and Method
Xiaomi is on a spending spree lately in hopes of...
eetimes.com
The (Power) Answer Is Blowing In The Wind
As a leading source of green energy, wind power is...
eetimes.com
SK Hynix, Sharp Move Up Chip Vendor Ranking
SK Hynix, MediaTek and Sharp are three companies that showed...
eetimes.com
Smart Factories Meet AI
The German Research Center for Artificial Intelligence (DFKI) has 47...
eetimes.com
Parasitic Extraction of FinFET-based Memory Cells
Memory chips must meet strict specifications for fast data transfer,...
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 +