Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [avalanche-breakdown]

In some types of otherwise well-isolating materials (isolators and semiconductors), under specific circumstances, the isolation can break down, releasing a transient, very high current

From wikipedia:

Avalanche breakdown is a phenomenon that can occur in both insulating and semiconducting materials. It is a form of electric current multiplication that can allow very large currents within materials which are otherwise good insulators. It is a type of electron avalanche. The avalanche process occurs when carriers in the transition region are accelerated by the electric field to energies sufficient to create mobile or free electron-hole pairs via collisions with bound electrons.

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Why is Zener avalanche noise saw tooth shaped?

I have the following schematic of a Zener based noise source:- simulate this circuit – Schematic created using CircuitLab When built, an oscilloscope reveals a saw tooth noise signal at the "Noise" node, like: The time base is 1us/div. Can anyone…
Paul Uszak
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Does a LED also emit light when conducting in avalanche mode?

I wonder this by pure curiousity. If we polarize a LED in avalanche mode by applying a very high reverse voltage (but keep the current low so that the component doesn't fry), is it possible that it also emits light when used this way ? (The reason I…
Bregalad
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Noise Model for Zener Diodes

I am trying to design a noise source using discrete transistors and a Zener diode in the avalanche breakdown region. Therefore, I have several questions relating to the use of the diode... How does the quiescent current effect the noise…
Caleb Reister
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Is there an analytic expression for the avalanche and Zener diode VI curves?

Ordinary diodes obey the Shockley diode equation, but I can't find anything similar for avalanche and Zener diodes. It's easy to find their VI curves, crude piecewise fits and lots of descriptions of how it works. I could also extract the numerical…
ions me
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Is reverse breakdown destructive for diodes?

Take a PN or Schottky diode and apply a reverse bias voltage. Go beyond the absolute maximum reverse voltage (given by the datasheet) and limit the current to a low value, such that \$P = V\cdot I\$ is low enough to not thermally destroy it. In this…
Alessio Caligiuri
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Avalanche ruggedness

How is a high avalanche ruggedness physically achieved for a MOSFET and what are the trade-offs in other parameters to get a high avalanche rating. Also, how should one interpret the avalanche energy listed in the datasheet? Another way to state…
walkingcrane
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Distinguish if this component is a PIN Photodiode or an APD Avalanche Photodiode

I am experimenting with a DFB Laser salvaged from a scrapped GPON Router. Laser works fine, but it comes with what looks like a "Built in InGaAsP monitor photodiode" incorporated into the laser. Here is a picture of how it looks like: Pinout…
Ezequiel Adrian
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What is the explanation for the shape of the Zener avalanche effect?

The following diagram is a trace of a Zener diode in avalanche. I can understand the explanations behind shapes A - D, but what causes shape E? A is the accumulating charge within the junction's capacitance, and thus follows the common exponential…
Paul Uszak
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Is the avalanche effect in Zener diodes a quantum mechanical process?

Firstly I would like to emphasise the word avalanche as it's fundamental to my question. I'm not concerned with shot noise, thermal noise or trash music. There is a video that explains the avalanche effect inside a Zener diode, from which the screen…
Paul Uszak
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Why reverse polarity causes damage

Is it because it can exceed the reverse breakdown voltage of semiconductors? For instance in low voltage devices say 1-5v is the reverse voltage rated a lot lower than that for damage to occur? Also I watched a video where a car battery was…
ohmmy
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How to use MOSFET in avalanche mode?

I'm thinking of a very simple circuit to generate high voltage pulses, like this: simulate this circuit – Schematic created using CircuitLab The MOSFET in this case will turn on until the current through L1 ramps up to 10A, then turn off. The…
Alex I
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Why do Zener diodes have a lower breakdown voltage than normal?

Here I do not understand some physics. So for normal diode we have a depletion zone width say Wn, and for Zener diode we have Wz. Then, we know that Wn > Wz. By reverse-biasing we make the depletion zone wider, until Epn is too high, and eventually…
Roman
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BJT Base-Emitter Reverse Breakdown

In the following (partial) circuit, the transistor is usually in its regular forward active mode. However, when the supplies collapse abrubtly - e.g. during power-down - the base-emitter junction can be transiently reverse biased with more than the…
tobalt
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Avalanche relaxation oscillator biasing resistor

I've tried the circuit in this article. It works very well and I've obtained 2ns clear pulses at 150 V (the main issue was to find the right avalanche voltage, which turned out to be 150-160V for my 2n3904 transistor). While the basic principles of…
MikeTeX
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Tuning BJT avalanche noise

I'm playing with the idea of building an audio noise maker. I found several nice sources. Most seem to be based on PN junction avalanche noise. As a starting point, I put this on a breadboard: It works, but I'm not sure I understand it completely.…
Blair Fonville
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