Skip to main content

Questions tagged [reverse-breakdown]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
4 answers
180 views

How do I light an LED on a ground signal when I don't have enough voltage left after the PNP?

I am working with a circuit that grounds when a LED is to turn on. I have an 8V supply voltage for the LED, which cannot exceed 10mA. The signal to turn on the light is a very weak 6.5V, so Vbe is ...
KJ7LNW's user avatar
  • 2,190
0 votes
1 answer
71 views

Transistor withstand voltage tester

There are some cheap transistor withstand voltage testers around. Aliexpress and eBay are full of them for under $20. I guess the principle is that the tester increases the voltage (with current ...
Chupacabras's user avatar
  • 5,508
-1 votes
1 answer
54 views

Reverse Breakdown Voltage for a diode

Could anyone explain why is the reverse breakdown voltage measured for a general diode? Diodes work in the forward biased region. Then why is it important to know the reverse breakdown voltage?
Curious_guy's user avatar
6 votes
3 answers
2k views

MOSFETs stabilizing current in coils keeps burning, how to protect them?

I am trying to stabilize the current in coils in my experiment. For that I am using a circuit as in the picture: First section is a fast switch. It is also galvanically isolated from the TTL signal ...
Einaudi's user avatar
  • 63
0 votes
1 answer
58 views

Reverse breakdown voltage over series elements

The M2* FETs are 100 V graded while D_pass is 150 V. Will the FETs' body diodes help them survive a negative 150 V spike?
kellogs's user avatar
  • 1,061
5 votes
0 answers
118 views

Why does output of this reverse bias noise source not have normal distribution?

I am trying to build a noise source based on reverse biased PN junction (i am trying to replicate this project https://altusmetrum.org/ChaosKey/ ). At this point i tried multiple iterations but so far ...
pigster's user avatar
  • 51
11 votes
3 answers
416 views

How to avoid or compensate for reverse biased base-emitter breakdown in this BJT active clamp design?

This active clamp design is elegant and simple, and works well to prevent OUT from exceeding the supply voltage (+15V), but fails when IN is low enough to reverse bias Q1's base-emitter junction ...
Simon Fitch's user avatar
  • 39.2k
5 votes
1 answer
374 views

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 ...
Ezequiel Adrian's user avatar
2 votes
1 answer
295 views

APD (Avalanche Photodiode) Active Quenching Circuit (AQC) Waveforms & Circuit Behavior

I am reading a paper tiled Avalanche photodiodes and quenching circuits for single-photon detection The paper presents an Active Quenching Circuit schematic, briefly describes its operation, and shows ...
Cole Fehr's user avatar
2 votes
3 answers
494 views

How to reduce NPN reverse base current on this interesting "Super Efficient Joule Thief"?

Note: The question part is the fixing of the negative current at the transistor base. It looks like there's a problem with negative current at the LED(s) -- this is not expected to be answered in this ...
MicroservicesOnDDD's user avatar
0 votes
1 answer
220 views

Ideas for protecting the input of an opto against high reverse voltage

I've been given a circuit to test and pointed out that the potential reverse voltage across the led in the opto will exceed the spec. The cct is a dual input with an opto on each channel, which feed ...
mikey_jp's user avatar
3 votes
2 answers
1k views

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 ...
tobalt's user avatar
  • 22.5k
2 votes
1 answer
886 views

Zener diode - Zener voltage vs reverse voltage specification

This may be a very simple question with a straight-forward answer, but I cannot get a clear answer on this. Consider the following Zener diode. The table on page 2 lists a column for Zener voltage \$...
wave.jaco's user avatar
  • 665
6 votes
1 answer
1k views

TVS diode specs - clamping voltage lower than breakdown voltage?

Having read this app note (and a few others) and quite a number of TVS datasheets, I came across one that is bugging me a bit. All of the TVS datasheets that I have read so far describe the the ...
wave.jaco's user avatar
  • 665
-1 votes
2 answers
3k views

What is the main difference between a zener diode and normal diode?

I have read that zener diodes at some certain voltage let current flow through itself when it's reverse biased, but why can't the same happen in normal diodes? What is the use of zener diode?
Pərviz Piri's user avatar
1 vote
1 answer
716 views

Base-emitter reverse breakdown and current

I have a circuit as follows, simulate this circuit – Schematic created using CircuitLab which provides a control current to an OTA as \$i_\mathrm{abc} = (3.27\mathrm{V} - V_\mathrm{in})/R1\$. ...
Timo's user avatar
  • 1,259
0 votes
1 answer
122 views

Why does the Zener diode's simulation model differ so much from datasheet specifications?

I was trying to design a circuit with a Zener diode by using its datasheet specifications and noticed there was a very big difference between the design and the simulated circuit. After inspecting the ...
rafaelfp's user avatar
  • 141
1 vote
2 answers
640 views

Interpreting the differential resistance of a Zener diode

I have this Zener diode - 12V rated C part. I just want to understand how to read the differential resistance column on table 8 for Zener current of 1mA and 5mA. Suppose I give an input voltage of 16V ...
user avatar
1 vote
3 answers
6k views

Zener Diode Reverse Current

I have this - Zener Diode - 12V Reverse Voltage On the table 8, I can see the ranges for the 12V reverse voltage is between 11.4V and 12.7V for the "C" selection part. But this value if for ...
user avatar
1 vote
1 answer
149 views

Potentially unusual LED failure

One of the LEDs in a plug equipped with over-voltage protection does not light up when the device is plugged into the 230 V mains. It has worked well for a while since the product was purchased. An ...
Daniel Tork's user avatar
  • 1,418
2 votes
1 answer
544 views

reverse bias of the gate of an N-channel enhancement mosfet

So how negative can I drive the Vgs of an N-channel Mosfet before damage occurs? Datasheets specify BVDSS and BVGSS but these are "forward" breakdown voltages -- ie the absolute maximum Vds before ...
jrive's user avatar
  • 639
2 votes
0 answers
90 views

Can reverse breakdown voltage be used to simulate lifetime aging of phototransistors?

As phototransistors age, their responsivity to light decreases (a fixed amount of light generate less photocurrent). To simulate long-term aging of phototransistors in a short period of time, one can ...
ach-agarwal's user avatar
2 votes
2 answers
1k views

Any importance to TVS 'parallel' vs 'series' Topology?

I am working with an existing schematic which has bidirectional TVS surge protection, laid out like this: simulate this circuit – Schematic created using CircuitLab The TVS diodes are ...
Tom's user avatar
  • 59
0 votes
0 answers
199 views

Why do diodes adjust to reverse breakdown voltage when we apply a voltage more than the breakdown voltage?

When a voltage(neglecting sign as I am considering reverse bias region) more than the reverse breakdown is applied then why diodes adjust themselves to reverse breakdown voltage? Please provide an ...
Trilok Girish Kamagond's user avatar
2 votes
1 answer
373 views

HFA3096 transistor array breakdown voltage

In the book Learning the Art of Electronics, one of the labs is to build a differential amplifier with a CA3096 transistor array. The author admits that the chip may be difficult to find and gives the ...
pr871's user avatar
  • 1,167
1 vote
2 answers
806 views

what limits the maximum voltage of this optocoupler (6N137)?

In the datasheet it is stated that the maximum VCC voltage is +5.5V.(https://www.vishay.com/docs/84732/6n137.pdf) Because ive been told to question everything (and i have enought of them to kill one ...
Eric B Ahapaid's user avatar
0 votes
0 answers
114 views

How to find the resistance of a diode operating in reverse breakdown region?

I am tasked to find the small signal resistance of a diode operating in reverse breakdown region (not forward bias). Method 1: Is using the small signal resistance formula correct even in the ...
GordonJun's user avatar
2 votes
2 answers
949 views

Find cause of diode destruction from destroyed diode itself

Is it possible to find the cause of power diode destruction, ie. if it was destroyed through: reverse overvoltage spike (reverse breakdown and subsequent thermal destruction due to reverse ...
tk_'s user avatar
  • 173
-1 votes
1 answer
6k views

Led blinking with one NPN transistor [duplicate]

I am using scheme as shown below to blink an LED. But I'm using 9V battery source instead of 12V. I tried to use capacitors in range 100uF - 500uF to increase delay between blinks. Questions: ...
naintrakusam's user avatar
0 votes
2 answers
3k views

How to solve a a full wave rectifier with two diodes and a ground in the middle?

This is the problem I am trying to follow along with the solution but I don't understand what is happening, how do I handle the random ground in the middle?? is the node between d1 and d2 40Vpeek and ...
Rayin's user avatar
  • 11
2 votes
2 answers
576 views

Can a reverse biased diode be driven past its voltage rating but with current limited to few uA

If, for example, a Silicon diode rated at 100V is reverse biased at 200V (long term, not just very briefly) but in series with a few MegaOhm resistor such that the reverse current is limited to one ...
Naseer Ahmed's user avatar
2 votes
1 answer
429 views

Huge reverse current leakage in fast recovery diode for boost converter

I have a boost converter circuit that will boost 12 V to around 180 V. The circuit works pretty well but there is a huge reverse current in the fast-recovery diode right before the load. Here is my ...
Zahi Azmi's user avatar
  • 149
56 votes
5 answers
12k views

Are LEDs better than we think?

Conventional wisdom about LEDs says their maximum reverse voltage \$V_{R(max)}\$ is quite limited, usually in the 5V-8V range. So, for experimentation purposes, I wanted to bring an LED into ...
LorenzoDonati4Ukraine-OnStrike's user avatar
1 vote
4 answers
1k views

diode selection for large current reverse bias, small current forward bias

I'm designing a circuit where I want to pass a small test current from one leg, but block a large "firing" current (rocketry) coming from another leg in reverse bias. I have a 5vdc indicator line (...
Donald Gulledge's user avatar
2 votes
1 answer
469 views

How do zener diodes, silicon diodes, and base-emitter junctions differ in reverse breakdown mode?

Here's datasheets for all of the above, and what reverse breakdown-related information I gather from them: Nexperia BZV55-B10 10V zener diode Breakdown may damage the device for powers above 400mW, ...
mic_e's user avatar
  • 656
1 vote
2 answers
3k views

PC817 input features

I'm designing a new circuit and I need to know if PC817 allows AC voltage input around 230V. I've tried with DC Voltage but never AC Voltage. Does anyone know if it operates with AC input?
Esteban's user avatar
  • 11
12 votes
1 answer
2k views

Are reverse biased transistors stable?

The usual circuit (found widely across the internet) for a true random number generator's (TRNG) entropy source is a reverse biased transistor like so: Q1 is typically a 2N3904 as it has been found ...
Paul Uszak's user avatar
  • 7,567
7 votes
8 answers
17k views

Maximum reverse voltage applied to a resistor-LED configuration

Consider the simple circuit below: simulate this circuit – Schematic created using CircuitLab LED datasheet: link Will the applying of a reversed 36 V to this circuit damage the LED? Knowing ...
fhlb's user avatar
  • 1,470
6 votes
1 answer
6k views

Diode emission coefficient and saturation current

I have created a Zener diode model in LTSpice, and now I am trying to simulate it with different values of the saturation current (IS), emission coefficient (N) and breakdown voltage (BV) using Spice. ...
abruzzi26's user avatar
  • 189
2 votes
1 answer
739 views

Protect phototransistor from emitter-collector breakdown

I'm using the ADC on the reset pin on an ATTiny85 to detect an IR level. The reset pin is disabled in the fuses but I would like the ability to "recover" the fuses and reprogram the device. The ...
bitshift's user avatar
  • 897
11 votes
1 answer
8k views

How protective diode protects transistor from breakdown?

Please, explain the process of breakdown; how exactly this protective diode protects the transistor? In a Horowitz & Hill book, "The Art of Electronics", 2nd edition, in "Chapter 2 - Transistors" ...
yulian's user avatar
  • 213