Questions tagged [semiconductors]
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 their conduction state. Silicon, Germanium, and GaAs are some usual materials. The term is also used to speak about devices that are made from such materials, for example, a processor from Intel can be called a semiconductor.
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Bipolar Junction Transistor operating modes
If I use a BJT transistor as a switch, the transistor operates in the saturation or cut-off region, not in the active region.
However, some sources use the formula IC = β·IB. However, this formula is ...
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Why are microprocessors made using silicon and not germanium? [closed]
I heard that microprocessors are usually made using silicon, yet germanium has a better conductive state.
Why isn't germanium not chosen instead, taking to account that better conductors provide ...
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Calculate the absolute value difference in work function for two diodes
Given two semiconductor diodes where one is silicon and the other is called Graham, and both are connected by ideal wires that do not affect their work functions, and they are also in thermal ...
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Who is the manufacturer of the Y31 5133 mic?
My question is in this PCBA I need the information of the who is the manufacturers of the mic the full details of that mic...
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Can I measure the internal termination resistance of a MIPI receiver?
This question is further to: How accurate are internal terminators on chips with high speed differential inputs?.
I would like to measure the actual termination resistance inside one of these chips (...
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How accurate are internal terminators on chips with high speed differential inputs?
I'm aware that due to process variation, some analog parameters of semiconductor devices can vary; sometimes quite a lot. (E.g. the SST3904 transistor specifies a DC current gain somewhere between 100 ...
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Purpose of Schottky diode in this schematic
I have come across the power supply management section used in the Verdin Development Board, addressing overvoltage, undervoltage, overcurrent, and reverse voltage protection.
While I understand how ...
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Process compatibility between a non-planar avalanche photodiode and planar CMOS at 0.130μm process technology node
I plan to integrate a non-planar P⁺⁺/i/P⁺/N⁺⁺ avalanche photodiode (APD) array with a peripheral control circuit (e.g., trans-impedance amplifier, analog-to-digital converter, and quenching circuit) ...
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Why does light doping imply a large temperature coefficient?
In a discussion about how one can make integrated resistors in a given IC technology, Gray, Hurst, Lewis, and Meyer (Analysis and Design of Analog Integrated Circuits) remark that if we want to use a ...
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Limit of applicability of "quasistatic"/capacitive picture of devices
When analyzing the transitories associated with switching in semiconductor devices, in textbook treatments one often sees the time dependence considered by including (potentially nonlinear) capacitors ...
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Why doesn't side diffusion raise resistance of an integrated resistor?
Consider forming an integrated resistor by diffusion of n+ dopants down into some p- substrate (the corresponding pn junction is reverse biased during operation). Let \$W,L,t\$ be the width, length, ...
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Why are drain and source not actually perfectly symmetric?
In textbook treatments, one has that the source and drain of a MOSFET are completely symmetrical and therefore interchangeable -- the distinction is only made by which is at a higher voltage in the ...
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How do P-type transistors conduct current?
Going through a Introduction to Computing Systems by Yale N. Patt and Sanjay J. Patel and currently reading a chapter on MOS transistors. From what I understand, N-type transistors "close" a ...
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What is meant by Switching charge ( under Gate charge characteristics) in the given MOSFET datasheet?
What is switching charge in this MOSFET datasheet?
The switching actually takes place during Miller region. Hence I belive Qgd should be called as switching charge. But looks like the remianing gate ...
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Interpreting Diode-Module Datasheet (Voltage Drop)
I'm trying to interpret the datasheet of a Dual-Diode Module, specifically the MF200C12F2N. The internal Circuit Structure is given below:
The Forward Voltage is given as 2.3V without any further ...
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Can "fried" semiconductor devices recover themselves over time?
When this whole "smart soldering iron" craze was just getting started, I jumped on the bandwagon and got myself the very first revision TS100. What I also got then is the complete inability ...
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What is the purpose of having fewer holes/free electrons in the collector region of a BJT?
The functionality of the NPN/PNP sandwich as a means for the base current to control the one directional flow of current makes sense to me.
However, I'm struggling to understand the details of the ...
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Can a chip be damaged if it goes above operating temperature while running?
An image sensor I'm using has the following temperature spec:
Absolute Maximums:
Ambient storage Temperature Max: 125°C
Recommended Operating Conditions:
Stable image temperature Max: 50ºC
...
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What is happening at the gate of a JFET to cause an electric field?
I am reading "Practical Electronics for Inventers" 4th edition and came across this circuit.
As I understand, for a JFET, current will flow from drain to source for a n-channel (opposite ...
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Clarification on Diode Recovery Times and Conduction State
I have a diode in my circuit with reverse voltage of 100 V and forward voltage of 2 V.
It experiences a reverse voltage of 100 V and immediately the voltage changes to 10 V in forward direction so it ...
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Understanding thermal instability breakdown in pn junctions
I am currently reading Sze (Physics of Semiconductor Devices, 3e, Chapter 2.4.1) and am trying to understand his discussion of thermal instability breakdown/runaway in pn junctions. I have also ...
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Why do PMOS suffer a worse body effect than NMOS?
Gray, Hurst, Lewis, and Meyer give the following discussion around PMOS transistors which I followed except for the sentence which reads:
Good use can be made of this fact in analog circuits to ...
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Using tunnel diode to cancel out armature resistance
Can we use tunnel diodes to cancel out armature resistance?
A tunnel diode when it is in its negative differential region under DC shifted AC(AC with some DC offset) and if the Vp-p of the AC is very ...
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Confusion about why pn junction discussion insensitive to doping variations faster than Debye length
Sze (Physics of Semiconductor Devices, 3e) gives the following discussion which relates to how equilibrium electric fields/equilibrium potential build-up at thermal equilibrium are related to doping ...
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Does \$\phi_{bi}\$ depend on applied voltage in non-uniformly doped junctions?
Consider a linearly graded junction
$$N_D - N_A = ax$$
for some grading constant \$a\$.
Using the standard simplifying assumptions one finds that the depletion region extent is
$$x_{SCR} = \left[\frac{...
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Semiconductor theory
Why is there no resistor in the circuit when analyzing hole and electron currents according to semiconductor theory?
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How can I calculate the amount of crosstalk/parasitic capacitance between two plates with different voltages across them?
I will preface this with the fact that I am a nuclear engineering student, not electrical, but I am working on a senior design project that might as well be an electrical engineering project. We don't ...
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Can I calculate beta by using the quiescent point and a voltage divider?
How can I calculate beta with only the data in the image?
Q is the quiescent point. I've tried with the basics Vcc formulas, but since it doesn't provide any value for Vcc I could not proceed.
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Why do series NMOS do better than a single NMOS from a delay perspective?
My VLSI text (Weste and Harris) writes the following:
Transistors in series drop part of the voltage across each transistor and thus experience smaller fields and less velocity saturation than single ...
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What does "strobe" mean in the context of semiconductors?
I was reading the data sheet for SN7425, and it calls the semiconductor a "Dual 4-Input NOR Gates With Strobe"
What does it mean by "Strobe"? Does it affect input/output?
https://...
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How does a floating diffusion node store and clear charges?
I'm currently studying CCD sensors. This article below attempts to explain how electrons are collected into a floating diffusion node, and then cleared when a reset voltage is applied to it. I don't ...
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Effect of semiconductor doping on threshold voltage
After reading online, I have modeled this as an relation between the threshold voltage and the doping concentration:
For a N-channel MOSFET on a P-type substrate:
$$
V_{T,N} \propto \sqrt{N_{A}}
$$
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How electrical current works in intrinsic semi-conductors
I understand that there are two types of currents going on when voltage source is applied in pure semi-conductor material - electron current and hole current. What I'm trying to do is imagine it.. So ...
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Semiconductor PN Polarity
When you apply voltage to the PN semiconductor and you achieve equilibrium, why is the N side still negative (-) and P side still positive (+) when considering that all of the ions have 4 valence ...
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Minority carriers in P-N junction
Are the minority carriers (free electrons in p-type and holes in n-type) created after the doping of silicon or after the n or p side get voltage across from a power supply?
And my second question is ...
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Is it possible to determine the Miller voltage of a MOSFET from the ON-region characteristics?
Miller's voltage from \$I_{ds}\$ vs \$V_{ds}\$ characteristics for different values of gate-source voltages. Miller's voltage or Miller plateau is the critical gate-source voltage at which MOSFET ...
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What is the Fermi level away from the p-n junction?
I understand that the Fermi level at the p-n junction must be the same between the materials forming the junction. To achieve this, the band energies of the n- and p-type materials are bent.
However, ...
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How to measure the electrical properties to ensure the performance of a thin electrode/insulator stack-up?
I am a mechanical engineer by trade, and I am looking at some basic electrical properties that I need to measure to ensure the device meets the desired performance.
The device consists of a two-layer ...
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Coupling heatsink RC network to MOSFET's Cauer circuit
I am trying to understand simple RC thermal simulation to analyse the temperature rise in Rohm a 1200 V N-channel SiC MOSFET SCT3040KR.
RC Cauer parameters are as depicted in the LTspice circuit ...
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How are Analog Chips produced?
I am curious about how analog chips are produced. I know that the most advanced logic are made with many rounds of deposition, etching, lithography, etc, but I haven't seen much material about how ...
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Seebeck Voltage [closed]
I understand that the voltage of two metal elements is V=(Sb-Sa)(T2-T1) regarding a thermocouple. But, what if mass was introduced to find the voltage? Can mass also be used to find voltage with ...
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Generating Double pulse using Tektronics Function generator AFG31000
I have Tektronics AFG 31000 function genertor with built in double pulse test app. I want to generate two pulses for my double pulse test but this so simple task is becoming a mountain to climb for me....
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Why do wide band gap semiconductors allow for higher electron mobilities?
Other than increased energy handling capabilities, one of the main advantages of using wide band-gap semiconductors like SiC or GaN in power electronics applications is that the switching frequency ...
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Why does the substrate of a MOSFET need to be lightly doped?
Image source: Electronics Tutorials - The MOSFET
MOSFETs were briefly discussed in my advanced materials class last semester and after reviewing the material, I was confused why does the substrate ...
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What exactly happens at the fundamental level if base voltage is higher than collector voltage in CE transistor?
In the first answer to this question, it is stated that:
This happens even if the base and collector are at the same voltage (!). Basically, one way to model a transistor is as the base-emitter diode,...
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How do you make M2 Ultra with lithography?
The M2 Ultra chip is unusual not because it's a single chip made of two halves, but because the halves are centrosymmetric images of each other instead of translation. Assuming the wafer is exposed ...
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Why aren't inverters used in a half adder made of NOR gates?
That's schematic of half adder using only NOR gates.
Why aren'y inverters used?
In the picture, there are 2 NOR gates where the two inputs are same as A or B.
Why don't we replace these with a NOT ...
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I want to make use of an Allegro A1324LUA-T Hall sensor to sense a very small magnetic field change. Would it be possible?
I am looking into using an Allegro A1324LUA-T for sensing very small magnetic field changes.
The data sheet shows that the sensor gives a 5mV/G change in voltage so I can sense a 0.1 Gauss change if I ...
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Understanding the formula of the saturation current in a PN-junction diode
According to Wikipedia, the saturation current in a diode is given by the following formula:
$$I_S = qAn_i^2\left(\frac{1}{N_D}\sqrt{\frac{D_p}{\tau_p}} + \frac{1}{N_A}\sqrt{\frac{D_n}{\tau_n}}\right)$...
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How to calculate the creepage distance of a package through package outline?
How do I calculate the creepage distance of a package which is not specified by the manufacturer?
By looking at the drawing of the package, could I calculate it? If yes then how?