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Questions tagged [physical-design]

This can refer to the design of the actual transistors inside an IC. That is also called IC layout.

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Tips for designing a permanent magnet synchronous generator?

I'm currently working on designing a permanent magnet synchronous generator for one of my personal projects and I'm having trouble getting a voltage I am satisfied with. My goal is to get around 4-6 V ...
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1answer
56 views

Working of NMOS as a capacitor

I came across instances where NMOS was used as a capacitor in analog circuits. This is done by shorting the drain and source. The drain/source acts as one terminal of the capacitor while gate acts as ...
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48 views

MOSFET treshold voltage

Does anyone know how MOS treshold voltage varies if the physical distance between source and drain decreases ?
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1answer
126 views

Machine learning for floorplanning

I have an educational assignment to make an floor-planning tool. Can I use machine learning in some part of the algorithm? For example, I was reading the book Algorithms for VLSI Physical Design ...
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1answer
134 views

Why do lead-acid batteries only last for a few years? [closed]

Why do lead-acid (automotive-style) batteries typically only last for a few years of regular use (or x amount of cycles) before having problems? Obviously, things can't last forever. But, what are ...
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13 views

Segmented Display With SMD Pads? (Not Thru-Hole or Half-hole SMD) [duplicate]

I'm looking through a product design, and I've seen these SMD / sticky segmented displays LCD being used. They are not hand-soldered, the segmented display appears to use some conductive sticky pad ...
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47 views

How can I calculate/estimate the resistance of the thin film structured like in the picture (top view)?

let's say the thin film is made of metal with resistivity rho and thickness t. I need to calculate the sheet resistance between point A and B. any reference suggestion is really appreciated.
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173 views

How to write MAC address to flash memory for RTL8153 (USB to ETHERNET)?

I have just designed usb-to-ethernet converter, which I use Realtek RTL8153 IC in and I cannot manage to write MAC Address into it via SPI bus. How do I achieve ...
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4answers
3k views

Do PCBs have schematics? [closed]

I have been studying electronics a bit at home in my spair time. I was wondering if manufacturers make schematics for PCBs? If I could get ahold of something like that i feel that I could understand ...
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2answers
175 views

How to design ultra low-power opamp?

I am designing a low-power opamp (differential amplifier) that will be used in the low-power consumption devices, e.g., power management circuits, portable devices, or energy harvesting circuits. I am ...
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2answers
2k views

Floorplanning vs Placement in VLSI

The major steps of physical design that I learnt from a VLSI lecture are: 1)Partitioning 2)Floorplanning 3)Placement 4)Routing. The question of mine is about the steps 2 and 3. It seems like the ...
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1answer
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Spinning Solar Cells at 50 hz make a pure sine wave? [closed]

What would be the out put of the solar panels spinning towards the sun? Ideal conditions would be o gravity in a vacuum tube or space.
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2answers
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What is standard about standard cells in layout designing? [closed]

Why are standard cells called 'standard' cells? Why couldn't it be just cells? What is Standard about them? (I'm talking about the common terminology used in layout designing wherein the standard ...
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1answer
510 views

Multiple Transistors (FinFET) sharing a gate?

Transistors are among the most fundamental components of electronic devices, and that to produce transistors with better performance, FinFET transistors have been developed: This allows for better ...
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3answers
93 views

Fear of electric arcs on a multiple outlet [closed]

I am physically near a multiple power outlet of the following model: The official page of the article is PowerCube |Extended| My doubt is: each outlet seems to close to each other. Should I fear ...
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1answer
370 views

Calculating resistance for metal layer from LEF File

I have a .LEF File which has various metals description and their parasitics information. I am trying to calculate R. It is specified as RPERSQ = 0.278. In the File description it is written as ...
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3answers
240 views

Help understanding practical transistor considerations?

So first, sorry if I make some incorrect assumptions or statements. If I do, just correct me and forgive my ignorance. It seems like everything I've been taught so far in classes about transistors ...
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1answer
42 views

GDSII stream reading

GDSII is a photomask\artwork format for photolitography. I am having trouble resolving a particular line in the file. For example, 'SRefs' means it refers to one of the structures and uses this ...
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3answers
728 views

Odd resistor design

In one of my designs, I specified the Rohm LTR10EZPF1003 100K 0802-Wide resistor: The issue is that when I added the resistor to the circuit, it creates a direct short: Measuring between the Green ...
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1answer
235 views

Is sinking mode and open drain the same concept in electronics?

I'm reading a few manuals about I2C , SPI where it says I2C ports are open drain,which I don't know what it is. I know about sinking mode and sourcing mode of ports in electronic circuits.
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1answer
34 views

What is the measurement grid in the context of strain gauge?

The sensor I am investigating is the 1-LM11 by Omega. I am looking at the specification at there are two metrics which confuse me, the measurement grid A is 1.5mm while measurement grid B is 2.5mm. ...
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1answer
273 views

Does this sort of connection on a Yagi Antenna make sense?

Here is an image of a WiFi yagi antenna I bought recently (and opened up for I could see no spectrum out of my SDR) I see that the coax has been connected to two plates, which I think act as dipoles. ...
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2answers
159 views

I need help with designing my first PCB on Proteus?

I've placed the component of a simple power supply circuit on PCB layout screen using auto-placer and auto-router. I would like to know many things about dimensions: Is there a standard space ...
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2answers
680 views

How is a signal physically routed in an FPGA?

I've looked at this similar question, but it does not provide the answer I'm looking for. The documents from Xilinx also confuse me and the diagram provided in the Implementation view of the Xilinx ...
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2answers
690 views

Source synchronous vs Common clock methodology in Physical design

The common clock and source synchronous clock scheme is explained here: http://referencedesigner.com/books/si/common-vs-source-sync.php. Question is: 1) How is maximum frequency attained with source ...
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2answers
158 views

Kick-off Spread Spectrum Clocking

Need of SSC: Spread spectrum clocking (SSC) is a special way to reduce the radiated emissions of digital clock signals. These levels or energy is radiated and therefore this is where a potential EMI ...
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1answer
405 views

School Project : To determine Eq. resistance of a cube whose each edge has a resistor, say R [closed]

Background I am a high school student, we are supposed to submit a Physics Project, individually. Since I have never done any Electrical Project/Experiment before, I came up with the idea of making a ...
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1answer
711 views

How to make a phase shifter?

I've gotten interested in beam-forming via a phased antenna array. I read a few articles/tutorials and they have very nice diagrams of antenna arrays and how the antennas interact to behind each ...
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1answer
191 views

Is it possible to reverse engineer a ROM chip by grinding and taking photos?

Recently someone made a claim that you can reverse engineer a ROM by physically grinding the chip and taking pictures of the various layers. Is this really possible?
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1answer
144 views

Clock nets Routing

We know that the clock tree synthesis is performed before signal routing. What is the specific reason for that. Or we can route both at the same time?
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5answers
2k views

Where is the cold junction on the commercial thermocouples?

According to all textbooks and articles, a thermocouple must have a cold junction somewhere on the middle of it. But none of the commercial products have a middle point or a marked spot for ...
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2answers
441 views

Muxes, Adders, Comparators, and Gates

This question is actually from one of my previous discussions, which I still don't understand how to implement. The goal is to use abstraction to design a circuit, which converts two-digit ASCII ...
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1answer
689 views

LM2907 schematic critique

I have been working with the LM2907 as I have been designing a few circuits around it. This has lead to me wanting to understand more of its inner workings and build up a breadboard model of the ...
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2answers
115 views

In logical progression, what things does a person need to know to design a robust opamp from BJTs

Opamps contain things like current mirrors, differential stage, push-pull pair and much more. Once a person starts from learning that BJT has 3 terminals for which Ic≈Ie≈βIb, what topics must a person ...
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Why are END CAP cells required in VLSI Physical Design?

ENDCAP cells are usually placed at the endings of rows. Why are they required ? Why can't we just use FILLER cells ? And what is the structural difference between ENDCAP cells and FILLER cells ?
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253 views

Physical push-down toggle button that pops up on voltage

I have encountered innumerable variations to functionally identical 2-lead physical switches, like the push-to-toggle buttons I am currently working with. Manually depressing the button toggles ...
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1answer
2k views

What is the physical size of a logic gate?

I always hear about process size improvements in the news, but could never figure out how it translates into dimensions of a logic gate. I found a chapter from Weste's CMOS VLSI Design, that contains ...
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3answers
1k views

When do I twist the wires going to transformer winding terminals, and why do I do it?

I sometimes see the wires of winding are twisted outside of the transformer (or inductor), as seen in the images below. What is the purpose of this? When should I twist winding wires and when shouldn'...
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3answers
5k views

Why do they crimp capacitor leads?

Most manufacturers produces crimped and straight lead pairs of their capacitors which has exactly same capacitance and voltage rating. Why do they bother crimping the leads? What advantage does it ...
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1answer
1k views

Antenna Design for specific directions

I am designing an antenna for a device and was hoping to gain some insight in the correct design direction for the antenna. The Idea: A receiver & antenna that fits in a 6" diameter by 3" deep ...
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3answers
247 views

Instructions on how to build electronic devices [duplicate]

I have got plenty of books in the theory of electronic devices, but I wish to build these transistors (BJT, MOSFETS, etc) and diodes by myself. Which books are there in offer to learn how to do this?
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1answer
488 views

What is “flush mount socket” in this 40yr old Tek scope?

EEVblog Dave shows us flush mount socketed IC's in this Tektronix 213 Portable Oscilloscope teardown, but it is hard to see and understand what exactly is a flush mount socket. Can someone explain how ...
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4answers
32k views

Make a custom plastic case

I have worked on many electronic DIY projects like MIDIbox (http://www.ucapps.de/), it always was fun and working but at the end, the problem was that I ended with a cool gear, but in a poor casing, ...
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2answers
5k views

1bit Full Adder Cell in IC not working as supposed?

I got an adder cell, which in IC mirror layout is this: EDIT: Transistor-level, standard adder circuit: Which I actually made in IC like this: It's not working as it should! I labelled it same ...
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1answer
632 views

Integrated Circuit Layout Design - Dynamic Flip Flop?

I need to create a dynamic flip flop like this: In integrated circuit technology, at mask layout level. I then want to create an 8bit register, using 8 of these flip flops, with a common CLK signal. ...
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1answer
527 views

Prevent Design Compiler from using certain cell types

I am building an RTL design using Synopsys DC and the GTECH library that comes along with it. It is generated using FD1, FD2, FD4 components. I would like to build the design without the FD2, FD4 ...
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2answers
300 views

How do you deal with worn wires?

Repairing a Macbook 4.1 (2008 model), I found something odd - the cables are breaking: The left side has a break in one cable's shielding (the wifi antenna most likely, as it's connected to a "...
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2answers
11k views

Please explain tech.lef , tech.lib

Can anyone explain what is in the tech.lef and tech lib files? Which stage of PNR (Place and Route) are they used for? Are ...
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0answers
118 views

Does the Black's equation work for immortal wires / interconnections (or only for mortal ones)?

I'm trying to understand whether the Black's equation is only true for mortal wire / interconnections or it is also applicable to immortal wires (essentially when its \$jL\$ product is less than \$jL_{...
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2answers
662 views

How do you make a shift/scale circuit using a transistor, resistors and a voltage source?

Given a resistive element that fluctuates between 0 and 10kOhms, a PNP transistor, a 20V source and a bunch of resistors, is it possible to construct a circuit with an output voltage as follows: 1) ...