Most generally a class of materials that are neither insulators or conductors in their natural state but which can be manipulated via doping or electric fields to change the conduction state. Silicon, Germanium, GaAs are some usual materials. The term is also used to speak about devices that are ...

learn more… | top users | synonyms

-5
votes
0answers
28 views

Leakage current variation with decrease in threshold voltage [closed]

As mosfets scale down and follow Moore's "Law." The voltages used on the mosfets also scale down. Do these newer, smaller transistors used in digital circuits have more leakage current do to ...
3
votes
1answer
61 views

Memory Power Supply

Kindly any one give the clarification on this. While going through a DDR Memory data sheet, I have found two (more than that) power supply pins. What is the necessity of this DLL power supply ...
1
vote
2answers
77 views

Can we find potential difference of a P-N junction by connecting voltmeter?

Can we find potential difference of a P-N junction by connecting voltmeter across diode terminals? I know the answer is no but i don't know how.
0
votes
0answers
33 views

Where does this effective field come from? Semiconductors

I'm having trouble with this question. I've had a look around but I can't seem to find the answer. Any ideas? Is this something that is specific to each graph or is it just always one of the ...
0
votes
0answers
27 views

Semiconductor electron velocity - unnecessary value?

the question says Calculate the electron velocity in a MOSFET of length 1 µm when a potential difference of 2.5 V is applied, assuming a channel doped at 1017 cm-3. Surely the doping amount isnt ...
0
votes
1answer
28 views

Semiconductor Doping Question

The question says: Calculate the minority carrier life-time in Si having a donor concentration, NA = 1014 cm-3 if the diffusion length for minority carriers is 150 m. Shouldnt it say "ND=1014"? ...
3
votes
1answer
103 views

Working of miniature Tesla coil?

Can anyone explain the given circuit. I seem to have done it and its perfectly working. But can someone explain the principle/theory and working behind this circuit from when the switch is turned on.. ...
0
votes
1answer
25 views

Analogy in combination of batteries in series and pn junction diode circuit to find potential difference

Can I use the analogy of combination of two batteries to get the potential difference between two points in case a pn junction diode is used in the case of other battery? In doing so what is the basic ...
0
votes
1answer
119 views

Why is the Collector current of a BJT transistor independent of the Collector Base voltage?

Ignoring the modulation of the effective base width, why is the collector current independent of the reverse bias voltage across the Base-Collector P-N junction? On one hand, it is easy to see that ...
3
votes
3answers
65 views

LED typical and forward voltages

So, I was going through the spec sheet of super bright 5mm orange LED, and it was listed that the forward voltage is between 1.8V and 2.5V. Below that there was a property listed as 'typical voltage' ...
-1
votes
1answer
69 views

At any given semiconductor node, how many fabs in the world? [closed]

Let's pick a node, say 45nm. How many wafer fabs are there worldwide that can produce chips with that resolution? Tens? Hundreds? And does this mean that producing equipment for them is almost a ...
2
votes
1answer
72 views

Why does the MOSFET drain current increase abruptly when Gate voltage is greater than the threshold voltage?

As far I've understood, channel formation takes place because of the induced negative charge on the semiconductor side of the gate capacitance. So shouldn't the charge concentration increase linearly ...
0
votes
0answers
29 views

About FET conducting channels

If we have a doped nanowire(given diameter and length) with the gate wrapped around it. How do we calculate the number of dopant atoms in the conducting channel? and Fermi level?
0
votes
1answer
42 views

Inter die vs Intra die process variation

Due to fabrication process, there will be variations, among wafers as well as among dies across a wafer. My question is that what variations are significant between dies? And what variations are ...
1
vote
0answers
23 views

What does the channel voltage in a MOSFET really mean and how does it lead to the Fermi level splitting shown?

Many books (Chenming-Hu Ch.6 Page 15, Neamen Page 413) use the term 'channel voltage' \$V(y)\$ to mean 'the potential in the inverted channel at a point \$y\$ distance away from the source along the ...
4
votes
1answer
274 views

Why do electrons move faster than holes in a semiconductor?

When an electron leaves, then only a hole is created, and when another electron fills it, then only the hole moves, so in that way, both should conduct current at the same speed. Yet I've been told ...
2
votes
1answer
38 views

How to design Digital logic gate using TFET logic?

In my recent project, I need to design digital logic gates using TFET instead of CMOS logic. Can someone Suggest any simulator or procedure which support design using TFET logic?
0
votes
2answers
47 views

Current limit and current gain bjt question

Contact potential of Vbe in Q2=Vbe-on I worked out that the maximum current that can go through R2 is Vbe-on/R2. So my question is why does Q2 turn on when the emitter current of Q1 reaches this ...
2
votes
1answer
78 views

Why doesn't the gate voltage drop entirely across the oxide in a MOS capacitor?

As the title says, for a MOSCap with, say, a p-doped semiconductor substrate, when a gate voltage \$V_{g}\$ is applied across the gate and the grounded substrate, why doesn't \$V_{g}\$ drop entirely ...
1
vote
3answers
61 views

How does a forward biased diode conduct electricity?

I am having a hard time imagining the flow of current through the p-n junction. When a diode is forward biased, the holes on one side of the barrier and electrons from the other side try to cross the ...
1
vote
2answers
53 views

Quick junction / pn junction diode clarification

I was studying diodes. I was at the part where we talk about P-N junctions diodes. There is a part I am confused about. Is the "junction" part the part in the middle which blocks the current if no ...
0
votes
0answers
37 views

Problem about n-doping and p-doping in semiconductor

Q7) This problem concerns a sample of Semiconductor X. At room temperature in Semiconductor X, the intrinsic carrier concentration, ni , is 107 cm-3 , the hole mobility, μp, is 300 cm2 /V.sec, and the ...
0
votes
1answer
41 views

Semiconductor Condution

I've read that semiconductors (i.g. intrinsic silicon) behave as insulators at absolute zero (since all valance electrons are shared via neighboring atoms). My question is, does conduction still take ...
0
votes
1answer
52 views

Self Heating of LED

I am using Red LED connected to B2902A SMU which can display current Voltage curve only.But i need to find out what is the temperature(Self heating) and how to find it using I/V curve.So that i can ...
1
vote
0answers
55 views

Semiconductor Level Genetic Programming

I was reading a most likely old article about, Adrian Thompsons work on using genetic programming to generate circuit solutions for simple tasks such as frequency differentiation. This got me ...
3
votes
1answer
95 views

How do wires connect to transistors?

So I was looking at the schematic of NPN and PNP transistors which basically involved layered blocks of doped material stacked. My question is how do wires connect to these devices? I think this ...
0
votes
1answer
34 views

Semiconductor thermal equilibrium [closed]

What precisely thermal equilibrium implies in case of a semiconductor. One thing I know is that Fermi Level remains the same. But what other things does this implies, is there net current flow in case ...
0
votes
1answer
151 views

How can computer replace PLC in industrial machines? [closed]

I am having internship in a semiconductor manufacturing company and learning about machines in front-end section. Technicians say that the machines all use computers as they process multiple complex ...
0
votes
0answers
56 views

Power and battery questions for nrf51822

I'm planning to create a new product which uses the nrf51822 chip and therefore I am doing some research for my initial questions that I have. I am new to electronics so please be gentle. The ...
3
votes
3answers
108 views

Is there an electronic device that stays “on” until the current through the device reaches a certain level?

I have the vague recollection that a device like this exists. The device is gated on, after which it approximates a short circuit, until the current through the device rises to a set level, at which ...
1
vote
1answer
130 views

Relationship between band gap and built in potential for PN Junction Diode in equilibrium?

I wanted to know the relationship between the band gap (Eg) of the p/n regions in a diode and the built in potential in equilibrium. My intuition says that Eg = e*Vo. I did a small calculation for ...
0
votes
1answer
66 views

MOSFET Ltspice determine some parameters

I am working on project for flyback converter using Ltspice. Indeed, I have to insert the parameters for MOSFET inside the model but I have faced some difficulties to get the values from datasheet for ...
0
votes
0answers
44 views

current density vs voltage curve in OLED

What is a current density vs voltage curve? what could be an ideal white organic LED's plot? Can someone explain how to understand a J-V sweep?
1
vote
1answer
135 views

How does a junction-less transistors work?

I have recently read in a book that in 2010,junction-less transistors were developed. I can't understand how a junction-less transistor can be used to amplify current or voltage with having any ...
3
votes
3answers
707 views

Is there a fundamental limitation on how rapidly (with voltage) can a diode ’switch’ ? If so, can you pinpoint its origin?

Is there a fundamental limitation on how rapidly (with voltage) can a diode ’switch’ ? If so, can you pinpoint its origin? The diode here is a 1N914
1
vote
1answer
86 views

How does an IV curve of a bulk semiconductor look like?

What would an IV curve of a bulk semiconductor (i-type/n-type/p-type) look like if I do a typical voltage sweep?
0
votes
3answers
217 views

How exactly does a transistor amplify the input current in CE configuration

I have gone through tons of forum discussions and videos and books but they all explain in terms of mathematical equations that factor the input by a 'larger than 1' number. What happens physically ...
11
votes
3answers
1k views

Why does the intensity of light in LEDs not increase with current after a particular value?

I read in books that light intensity from an LED does not increase beyond a certain value of current. The amount of light emitted depends on the combination of holes and electrons. If so, then as the ...
2
votes
2answers
137 views

Thermal Runaway in Diodes

Datasheet for 1N5406 diode states "3.0 ampere operation at Ta = 75°C with no thermal runaway". What does this mean exactly? Can I place these in parallel to increase current capability?
0
votes
0answers
60 views

JFET - Pinch off voltage value

I have a JFET channel N and I have N_A, N_D, V_TH and the width of the channel without any bias voltage applied. I need to know the cut-off voltage. The cut-off voltage is the pinch-off voltage, ...
-1
votes
3answers
574 views

Why does a BJT act as an amplifier in the linear region?

I'm covering BJT's in my semiconductor class and in lecture, the professor said that BJTs are used as amplifiers in the linear region. I'm confused because I thought the gain was proportional to the ...
4
votes
4answers
628 views

Do LED have an unproductive base power consumption like incandescent bulbs?

To generate light from an incandescent body, like a tungsten filament, the body needs to be heated up to a temperature minimum needed to emmit light from that material. Up to that minimum ...
1
vote
3answers
683 views

How is a semiconductor electrically neutral?

I'm in the process of learning how transistors works, which starts with understanding how doping is used to create n-type and p-type semiconductor materials. All the resources I've read sort of ...
-3
votes
1answer
86 views

Which Material is used for High Speed Devices Germanium or Silicon & Why?

Actually i am get confused with electron mobility & it's role in deciding a material for Some particular application.
0
votes
2answers
75 views

Using a single inverter to turn a light off

I'm planning on adding two strips of LED lights to the edge of my headlight enclosure. This is obviously an aesthetic "mod" however I'd like it to be semi useful as well. I'd like to be able to wire ...
1
vote
1answer
111 views

What happened to my second half cycle of my half wave rectifier?

When I'm doing a simple half-wave rectifier with the set-up as shown above (Note: Diode D2 is not connected) and connected terminal 5 and 4 with positive and negative terminal of oscilloscope, this ...
20
votes
2answers
2k views

Why are silicon wafers used in semiconductor production round?

Wafers used for making semiconductors are round -- but this wastes quite a few chips around the periphery of the wafer in the fabrication process. Wouldn't it make sense to make the wafer as a square ...
0
votes
1answer
41 views

Question on uniform semiconductor doping

So my question is shown above. For sample A , I tried to substitute the value of NA into the equation for law of mass action , but I was unable to get the answer. I had to use the equation for ...
3
votes
3answers
550 views

How do holes conduct current?

I have some questions about holes in a semiconductor. When I checked the net I found holes are said to be equivalent positive charge and they say because the hole moves from one place to another when ...
0
votes
1answer
123 views

Why diodes are made up with semiconductor?

I am little bit confuse about 'Why diodes are made of semiconductors'. I know the properties of semiconductor and also know the process of doping but still confuse to get the answer. Why the making of ...