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Topic: Avalanche diode


  
  Planar avalanche diode with a breakdown voltage between 4 and 8 volts - Patent 4323909
The avalanche is non-uniform, due to the structural defects of the junction which are difficult to obviate (heterogeneous doping of the substrate, heterogeneous concentration of the doping agent and dislocations induced by diffusion).
During diode operation, these alkaline ions progressively migrate towards the junction-surface intersection zone and modify the distribution of the space charge and consequently the initial breakdown voltage of the diode.
According to the present invention, a guard ring diode is provided in which, within the zone defined by said ring is provided on intersection of the junction with the shallowly diffused layer at the surface of the said diode in order to determine the avalanche threshold.
www.freepatentsonline.com /4323909.html   (2192 words)

  
  Diode | Topic Definition | Find the Meaning and Define the Answer of Diode   (Site not responding. Last check: 2007-11-05)
The first diodes were vacuum tube devices (also known as thermionic valves), arrangements of electrodes surrounded by a vacuum within a glass envelope, similar in appearance to incandescent light bulbs.
The arrangement of a filament and plate as a diode was invented in 1904 by John Ambrose Fleming, scientific adviser to the Marconi company, based on an observation by Thomas Edison.
A diode's current-voltage, or I-V, characteristic curve is ascribed to the behavior of the so-called Depletion Layer or Depletion Zone which exists at the junction between the differing semiconductors.
www.thefreeencyclopedia.com /definition/word.aspx?w=Diode   (2449 words)

  
 Diode
In Thermionic diodes, initially, current is made to pass through the cathode, which comprises of filament treated with a mixture of barium and strontium oxides.
When voltage is applied to semiconductor diode with positive voltage applied to p-side and negative voltage applied to n-side, holes from p-side region combine with electrons in n-side region, resulting in narrowing of depletion layer and flow of current from p-side to n-side.
When voltage is applied to semiconductor diode with negative voltage applied to n-side and positive voltage applied to p-side, holes from p-side region move towards in a direction opposite to n-side region and electrons in n-side region move in a direction opposite p-side region resulting in widening of depletion layer.
www.jimdirectory.com /1/diode.htm   (450 words)

  
 Diode Information - laser diode
A semiconductor diode's current-voltage, or I-V, characteristic curve is ascribed to the behavior of the so-called Depletion Layer or Depletion Zone which exists at the p-n junction test a diode with a meter between the differing semiconductors.
For silicon diodes, the built-in potential is approximately 0.6 V. Thus, if an external current is passed through the diode, about 0.6 V will be developed across the diode such that the P-doped region is pin diode bias positive with respect to the N-doped region and the diode is said to be 'turned on'.
For special purpose diodes like the avalanche or zener connectorized laser diode diodes, the concept of PIV is not applicable since they have a deliberate breakdown beyond a known reverse current such that the reverse voltage is "clamped" to a known value (called zener voltage).
www.inanot.com /Ina-Electronics_Topics_D-/Diode.html   (3034 words)

  
 Diode - Engineering - A Wikia wiki   (Site not responding. Last check: 2007-11-05)
In vacuum tube diodes, a current is passed through the cathode, a filament treated with a mixture of barium and strontium oxides, which are rare earth metals.
For silicon diodes, the built-in potential is approximately 0.6 V. Thus, if an external current is passed through the diode, about 0.6 V will be developed across the diode such that the P-doped region is positive with respect to the N-doped region and the diode is said to be 'turned on'.
For special purpose diodes like the avalanche or zener diodes, the concept of PIV is not applicable since they have a deliberate breakdown beyond a known reverse current such that the reverse voltage is "clamped" to a known value (called zener voltage).
engineering.wikia.com /wiki/Diode   (2888 words)

  
 Semiconductor Devices
The term diode and rectifier will be used interchangeably; however, the term diode usually implies a small signal device with current typically in the milliamp range; and a rectifier, a power device, conducting from1 to 1000 amps or even higher.
However, for a real diode, other factors are also important: in particular, edge effects around the border of the junction cause the actual reverse current to increase slightly with reverse voltage, and the finite conductivity of the doped semiconductor ultimately restricts the forward current to a linear increase with increasing applied voltage.
This breakdown voltage is the zener voltage for zener diodes.
www.mtmi.vu.lt /pfk/funkc_dariniai/diod/p-n_devices.htm   (2760 words)

  
 Avalanche breakdown - Wikipedia, the free encyclopedia
This phenomenon is usefully employed in special purpose semiconductor devices such as the avalanche diode, the avalanche photodiode and the avalanche transistor, as well as in some gas filled tubes.
Avalanche breakdown is a current multiplication process that occurs only in strong electric fields, which can be caused either by the presence of very high voltages, such as in electrical transmission systems, or by more moderate voltages which occur over very short distances, such as within semiconductor devices.
In avalanche diodes, this effect is mainly used to construct overvoltage protection circuits and voltage reference circuits: as a matter of fact, avalanche breakdown and Zener breakdown are jointly present in each avalanche diode, depending on breakdown voltage what is the leading contribution process to the avalanche current.
en.wikipedia.org /wiki/Avalanche_breakdown   (762 words)

  
 Olympus Microscopy Resource Center: Photomicrography - Interactive Java Tutorials - Avalanche Photodiodes
An avalanche photodiode is a silicon-based semiconductor containing a pn junction consisting of a positively doped p region and a negatively doped n region sandwiching an area of neutral charge termed the depletion region.
Avalanche diodes are very similar in design to the silicon p-i-n diode, however the depletion layer in an avalanche photodiode is relatively thin, resulting in a very steep localized electrical field across the narrow junction.
This "avalanche" of electrons eventually results in electron multiplication that is analogous to the process occurring in one of the dynodes of a photomultiplier tube.
www.olympusmicro.com /primer/java/photomicrography/avalanche/index.html   (470 words)

  
 SPECIAL DEVICES
Diodes are two terminal semiconductors of various types that are used in seemingly endless applications.
The second theory of reverse breakdown effect in diodes is known as AVALANCHE breakdown and occurs at reverse voltages beyond 5 volts.
Operating a diode in the breakdown region does not damage it, as long as the maximum power dissipation rating of the diode is not exceeded.
www.tpub.com /neets/book7/26.htm   (1819 words)

  
 Diode - ExampleProblems.com
Diodes may be made from semiconductor materials such as silicon or germanium or may be fabricated using devices depending on thermionic emission: tubes (US) (or valves in UK).
Few electrons flow from the plate back toward the filament, even if the charge on the plate is made negative, because the plate is not heated and therefore does not eject many electrons by thermionic emission.
A semiconductor diode's current-voltage, or I-V, characteristic curve is ascribed to the behavior of the so-called Depletion Layer or Depletion Zone which exists at the p-n junction between the differing semiconductors.
www.exampleproblems.com /wiki/index.php/Diode   (2951 words)

  
 NCSR - Avalanche Diode
If the device has a designed breakdown voltage for which it is intended to be used it is called either a zener diode, breakdown diode, or an avalanche diode.
Common uses of breakdown diodes include, voltage regulators where the voltage is required to be a constant regardless of the current drawn.
A somewhat typical avalanche diode will have a specified breakdown voltage the example below is for a 7V breakdown, the breakdown equation below is somewhat contrived, but illustrates the idea of avalanche breakdown.
www.onr.navy.mil /sci_tech/31/312/ncsr/devices/avalanche.asp   (212 words)

  
 Avalanche-enhanced CMOS transistor for EPROM/EEPROM and ESD-protection structures (US5719427)
Since the avalanche electrons are generated by the diode rather than by the programmable transistor itself, programming efficiency no longer depends on the channel length and other parameters of the programmable transistor.
The breakdown voltage of the diode is adjusted by varying the lateral spacing between the n+ drain and the p+ diffusion.
whereby the avalanche-generating diffusion in close proximity to the drain diffusion initiates avalanche breakdown when the critical reverse voltage bias is applied, and whereby avalanche breakdown occurs at a lower voltage in the avalanche-breakdown diode than in the channel of the avalanche-enhanced transistor.
www.delphion.com /details?pn=US05719427__   (643 words)

  
 [No title]
The new n+pvnp+ structure for the avalanche diode was proposed some years ago to improve the frequency characteristics.
The phase delay, which was produced by means of two avalanche zones and the drift zone v is sufficient for the negative resistance obtain for the wide frequency region.
In fact, it was the amazing electroluminescence efficiencies of just such diodes that were reported at the Solid State Device Research Conference (SSDRC) on July 9, 1962 by R. Keyes and T. Quist [13] of the MIT Lincoln Lab group and a group led by J. Pankove at RCA Laboratories.
www.lycos.com /info/diode.html   (796 words)

  
 Correspondence Lesson 4: Electronics & Lighting Controls
One method has the diode symbol on the surface of the diode; another uses a band around the diode indicating the cathode; a third has the cathode end larger than the anode end; and a fourth has the cathode end beveled.
Since the ohmmeter's polarity is known, the diode end connected to the negative lead during forward bias must be the cathode; and the end connected to the positive lead must be the anode.
This is a reflection of the diode's PN junction temperature rise.
bg.ecmweb.com /ar/electric_correspondence_lesson_electronics   (3567 words)

  
 Diode Tutorial   (Site not responding. Last check: 2007-11-05)
A diode can be thought of as the electronic version of a one-way valve.
These are similar to tunnel diodes in that they are made of materials such as GaAs or InP that exhibit a region of negative differential resistance.
Some examples are Point Contact Diode, Varicap or varactor diodes, Current-limiting field effect diodes.
www.cpcares.com /Diode-Tutorial.html   (2154 words)

  
 The Unusual Diode FAQ   (Site not responding. Last check: 2007-11-05)
A backward diode is a diode with an extremely low breakdown voltage, causing it to conductor better in the reverse direction than in the forward direction.
The temperature coefficient of the avalanche mechanism is positive, that is, at higher temperature, the avalanche breakdown voltage increases.
When the diode was reverse-biased to the point of avalanche breakdown, a small fraction of the avalache electrons actually shot through the n-region and into a vacuum.
margo.student.utwente.nl /el/componen/diodefaq.html   (5939 words)

  
 wer-weiss-was | "avalanche diode: optimierung" | aus Forum Elektronik allgemein
avalanche diode: optimierung (M i c h a e l a, 23.11.2000 09:02)
Re: avalanche diode: optimierung (W o l f g a n g D r e y e r, 23.11.2000 09:37)
Die Si Avalanche Diode ist "uber einen Kondensator mit Erde verbunden, zwischen Diode und Kondensator ist noch ein Widerstand mit einem bias von -150V angeschlossen.
www.wer-weiss-was.de /theme59/article442219.html   (423 words)

  
 Diode provides fastsoft recovery., Fairchild Semiconductor
Diode is available in single and dual packaged configurations in TO-220 and TO-247 packages, as well as surface mount TO-263 package.
Soft recovery minimizes ringing to expand the range of conditions under which the diode may be operated without using additional snubber circuitry, while reducing EMI and improving system reliability.
Apr 29, 2005 - Transistors and Diodes are used in portable applications.
news.thomasnet.com /fullstory/11457/4300   (724 words)

  
 MB-60 Avalanche Diode Tester - AMTEST Vehicle Test Equipment   (Site not responding. Last check: 2007-11-05)
Avalanche diodes are used in newer alternators to protect the car's computer, radio, and other electronic equipment from over-voltage conditions and high-voltage spikes.
Avalanche diodes cannot be correctly checked by traditional diode checks.
The MB-60 measures breakdown voltage (using internal 32V source with limiting resistor) and pre-regulation leakage current (using internal 20V source) with a sensitive 200 microamp meter to be sure the avalanche diodes meet manufacturers' specs.
www.glassmaster.com /controls/mb60.htm   (106 words)

  
 STMicroelectronics | TRISIL CROWBAR TYPE PROTECTION DIODE
Since the voltage to be taken into consideration for the calculation is that in the conducting state, the permitted current levels in transient operation are independent of the avalanche voltage and the guaranteed values are identical for all the types of a given series (see Figure 8).
This portion of the characteristic is identical to that of an avalanche diode.
As the avalanche current increases this difference of potential can reach the threshold of 0.6V, a value which is sufficient to create injection of electrons from the cathode towards the P1 area and thus trigger thyristor N1 P1 N2 P2.
www.st.com /stonline/products/literature/an/5649.htm   (1697 words)

  
 Encyclopedia of Laser Physics and Technology - avalanche photodiodes, photon-counting, photodetectors
An avalanche photodiode is a semiconductor-based photodetector (photodiode) which is operated with a relatively high reverse voltage (typically tens or even hundreds of volts), sometimes just below breakdown.
However, the avalanche process itself is subject to quantum noise and amplification noise, which can offset the mentioned advantage.
Silicon-based avalanche photodiodes are sensitive in the wavelength region of about 450-1000 nm, with the maximum responsivity occurring around 600-800 nm, i.e., at somewhat shorter wavelengths than for silicon p-i-n diodes.
www.rp-photonics.com /avalanche_photodiodes.html   (417 words)

  
 Add High Voltage Capability to the MAX471/MAX472 High-Side Current Sense Amplifiers - Maxim/Dallas
An avalanche diode and current source provide a floating power supply to allow high-side current sense amplifiers to work at up to 300V.
Use of a 33V avalanche diode for D1 pushes this to 333V.
Chose the current value to ensure that the avalanche diode is regulating.
www.maxim-ic.com /appnotes.cfm?an_pk=1934   (536 words)

  
 American Microsemiconductor manufacturers of Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits ...
The diac is a bidirectional trigger diode which is designed specifically to trigger a triac or SCR.
In this discussion the term diode and rectifier will be used interchangeably; however, the term diode usually implies a small signal device with current typically in the milliamp range; and a rectifier, a power device, conductin
A tunnel diode is a semiconductor with a negative resistance region that results in very fast switching speeds, up to 5 GHz.
www.americanmicrosemi.com /information/tutorial   (687 words)

  
 Rectifier Diodes - 4400V Avalanche Diode
The diode (rectifier) voltages shown below represent the maximum for each group.
Each table shows the voltage range for each diode (rectifier) type in ascending current order.
To view other diodes (rectifiers) click on the required maximum voltage shown below.
www.dynexsemi.com /products/rectifier_diode/4400.htm   (70 words)

  
 The Point-Contact Diode
The negative resistance in a simple pn-junction or pin diode is the result of a more
The avalanche region and the drift region of the
Diodes of the pn and pin type must use the same physical region for
www.tpub.com /content/neets/14183/css/14183_134.htm   (295 words)

  
 Avalanche photo diode detector - lavinfotodiod (English to Swedish translation glossary) laboratory medicine,Medical: ...
Avalanche photo diode detector - lavinfotodiod (English to Swedish translation glossary) laboratory medicine,Medical: Instruments,Medical
The KudoZ network provides a framework for translators and others to assist each other with translations or explanations of terms and short phrases.
metaforen fungerar även på svenska; lavinen (avalanche) åsyftar en snabb strömstegring.
www.proz.com /kudoz/1637592   (135 words)

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