Questions tagged [shielding]
Questions regarding shielding devices against noise, interference, or ESD. Not to be confused with arduino-shield.
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How to calculate the via fence spacing between two differential CPWG?
I designed a very compact 4 layer PCB that has many PCIe 2.0 differential pairs spaced in close proximity. In addition to the internal ground planes, I want to fill the signal layers with copper, and ...
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Is there any practical purpose of placing read only memory (ROM) chip near a hard drive?
Premise: a PCB file has ROM chips (I think they are masked ROMs?) placed beside standard 3.5" HDDs, which has lead me to a few questions.
While the product is off, I understand that the magnets ...
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Calculate RF shielding property of aluminum sheet
I want to quantify the radio-frequency shielding properties of a sheet of aluminum. I have an RFID antenna shooting at 865 MHz and I want to shield the antenna so that I don't pick up tags behind the ...
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Proper shielding of a specific circuit
I have a PCB, that will now be put into a conductive enclosure (connected to PE).
The PCB has some power electronics (DC/DC converters, motor controller etc.), some communication interfaces (CAN etc.) ...
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infrequent USB dropouts on SBC
I have a full speed USB audio device connected to the USB port on a SBC running Ubuntu Linux. I'm acquiring data over this connection and I need 24/7 uninterrupted data acquisition. If the USB ...
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RF shield mesh rules of thumb
When you place a RF transmitter within a metal enclosure with openings that can be approximated as a mesh, are there any rules of thumb for either letting the signal pass through or get attenuated?
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Cable / Device Shielding
Is it required to connect Shield cover to the enclosure at several points in a defined way? I am doing EMC simualtion related to this and not sure on what changes I can make.
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EtherCAT - Correct Shielding of Slaves
According to Beckhoff, the EtherCAT Standard needs correct shielding to work reliable, since EtherCAT cannot tollerate a lot of jitter:
Beckhoff Shielding
Correct shielding means, that the shield is ...
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Density of braid shielding
Does the shielding braid density depend on frequency range to provide good cable shielding? I have read that braiding works well for low frequency but that at high frequency the effectiveness ...
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Utility of shielding a laptop SSD with conductive foil -?
I recently replaced the factory SSD in my Thinkpad X260. The factory SSD came with one side covered in conductive aluminum foil which is grounded to the chassis via the caddy-screw attachment. The ...
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USB shielding, device or host side?
I have an SBC with a USB host port, but it is exposed as male header pins rather than a female USB port.
I have soldered female headers to a USB cable and have a working but intermittant connection, ...
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Question on the USB connector shileding
I have a USB microphone, based on cm6533 chip, that appears to be in working condition, with the exception of it's fried USB type C connector. Upon closer inspection this is the circuit that houses ...
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Would grounded conductors placed on skin prevent signals from reaching a shielded body part?
Here is the scenario:
You are in an environment where there are sources of EM signals that your body will pick up as though it were an antenna via capacitive coupling, i.e. what happens with the 50/...
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Ethernet cabling: UTP, STP, FTP, etc, when is shielding useful/needed?
When installing cabling for Ethernet purposes, the question often arises: does one want/need simple UTP or any of the shielded variants, i.e. F/UTP, S/UTP, SF/UTP, U/FTP, F/FTP, S/FTP or SF/FTP, often ...
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What's the intuition behind connecting a wire shield to the ground plane on a bare board?
I have an old (1970s) PCB that generates a (baseband, composite) NTSC video signal. It is a bare board without a containing chassis or case. I am using a shielded cable for the video output line and ...
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Shielding and PCB ground
When should I connect the shield of my cable to the PCB ground plane and what effect will it have?
In addition, what effect do those shieldings have on EMI, does the shielding block out HF or LF noise?...
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Why do I have higher noise at far end of a DC power cable even when unplugged at that end?
I have a 750W DCDC converter that is putting out 24v. The converter has a stated ripple max of around 600mV and when measured directly at the output (scope lead tip pin the the output, lead ground ...
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Doubt about grounding loop and shielding
Good morning,
first at all I want excuse me for my english and my inexperience.
I have working with complex setup (osciloscope+SMU+Waveform generator+ some circuits and shielding cage) and now Im ...
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What happens when the attenuation between radios in an RF test bed becomes higher than the RF leakage attenuation of the coax cables?
If I have an RF testbed with radios connected to each other via an attenuation matrix, what happens when that attenuation between radios exceeds the rated attenuation of the braided shield coax cable (...
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Shielded header cables or alternatives for IDC / 2x8 header cables
For my project I currently use 2x8 IDC cables, all of them carrying digital data, like SPI, I2C and TDM (digital audio). As I have tested, I found that these cables bring in loads of noise to the ...
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Failed radiated emissions test on USB cable - USB module hardware and firmware improvements
I posted a few days about ago how our product failed ESD testing. Well, it also failed radiated emissions testing so I thought I'd make a separate post.
The product is a 5V USB powered, non-radio, 3v3 ...
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How to connect the shield of a cable only on one side, if I need to transfer GND from one end to the other?
I have one jack output: Left, Right, GND. I am using a shielded cable to transfer this signal to an amp. I've read about ground loop and that I should only wire the shield of the cable on one of the ...
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Shielding issues with RJ45 connectors
I've been dealing with a pretty nasty radiated emissions problem at work and I've pretty well exhausted any list of potential solutions/mitigation tactics to resolve this given the design constraints. ...
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Shielding that retains some attenuation as \$\omega \rightarrow 0\$?
I'm new to the world of shielding.
It seems that with regular, "Faraday type", shielding you're at the mercy of the skin effect equation:
Which blows up as \$\omega \rightarrow 0\$
Are ...
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Thermocouple readings affected by PE
I designed a controller for an electric pizza oven. The PCB has an MP-LDE03-20B0 power supply module on it. Everything works great except for measuring the temperature in the oven. I use thermocouples ...
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RF noise filtering chassis or power return?
I need to place some filtering on the IO lines of a DC powered device.
The RF noise is induced or conducted into the chassis of the equipment and also into the interconnecting cables. The frequencies ...
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Does EMI shielding deteriorate with time?
Does EMI shielding sheets gain resistance/impedance with time?
I am using a ~2 year old RF EMI Absorb sheet that my roommate found and gave to me because my electronics keep interfering with his radio....
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Can I use a big piece of ungrounded metal as ground?
There is nowhere to ground; I don't have access to a copper rod that goes into the earth or to circuitry. In this room there are only wall outlets and a Czech hedgehog that is no longer used. It's not ...
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Is twisting a single ended signal with its own GND really useful?
I know that the most robust way of transferring an analog signal over long distances is via differential pairs which are twisted together and then shielded (shield grounded at one end only).
But ...
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Do I need via shielding for the GPS antenna trace?
I'm working on a 4 layer board (signal, GND, PWR, signal). I have a NEO-M8P GPS module and the Hardware integration manual says to connect the antenna with a 50 ohms impedance trace to the connector ...
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Puzzling mains-frequency interference at output of signal generator
The output from the 1940's-era modulated oscillator I'm restoring is being fouled by a 50Hz signal and I haven't been able to find the cause of it - so I'm far from being able to eliminate it. It's a ...
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What is going on regarding power toroid shielding? (some shielded, some unshielded, no apparent difference)
In this Digikey search for 47uH toroid inductors, the shielding column shows that some are considered shielded, and others are considered unshielded. And even from the same manufacturer (Bourns).
A ...
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CNC Servo System Grounding
Here it's a sketch of a simplified CNC servo system.
The servo drives are non isolated (Digital GND connected to Power GND, drawn as GND)
(My main question on the picture too)
#1: Why some ...
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LCD scrambled by interference from RF plasma
My lab uses a custom-built setup to generate reactive plasma; basically metal plates in a vacuum desiccator energized by a BD-10A. I've built an arduino-based control box for it to allow more precise ...
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When to employ RF shield cover on PCBA?
During reparations and teardowns I have frequently come across PCB-mounted RF shields and covers. While I don't typically work with GHz processors or design RF modules I wonder if such covers could be ...
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When the electric field EMF radiation hits tin foil why does it result in a magnetic field?
I have a cheap Erickhill EMF reader that measures “electric field” and “magnetic field”.
I’ve been experiencing an odd phenomena that I can’t quite explain of a electrical sound emanating from a ...
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Correct shielding in different situations
For me shielding is always a difficult question. I'm sometimes really unsure how I should connect the shield. What I know is that the shield should be connected with very low impedance, that for sure, ...
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How does electromagnetic shielding work?
How does electromagnetic shielding work in cables? I learned from school that foils are used as shields in coaxial cables to "shield" them from external electric and magnetic fields. It also ...
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Tips on designing a shielded stepped linear resistance box
I need a shielded, linear, stepped resistance for an experimental setup.
Requirements:
1000 Ohm to 1 MOhm
Resistance accuracy is not of high concern: +-1000 Ohm is acceptable
BNC in and out
50 kHz ...
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Do I need EMI shielding for a 5V signal PCB placed beside high powered DC cable 48V 50A?
I have PCBs located just below the high-powered DC cable at 50A 48V.
My PCB has input-output from 5V signal cables from all over the place.
The 5V signals are for:
12V and 5V Signal driving the EM ...
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Does a shielded inductor store less energy than an unshielded one?
As you can see in the image above, the magnetic field of the shielded inductor looks smaller, but does this mean the unshielded inductor can store more energy? (This all assuming the inductors are ...
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Optimizing Precision Photodiode Sensor Circuit Design-keep-out around the trace calculation
I am going through this document from Analog devices to learn more about different guarding methods.(https://www.analog.com/en/technical-articles/optimizing-precision-photodiode-sensor-circuit-design....
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Is it possible to shield a metal ball with electrostatic shielding, or any other way?
Is it possible to shield a metal ball by the electrostatic shielding such that metal ball doesn't suffer electrostatic induction?
There is an electric field present near the metal ball but I want that ...
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How should non-shielded connectors be handled in a casing design?
Assume a design with a mix of shielded connectors (e.g. USB, HDMI) and non-shielded connectors (e.g. standard 0.1" headers)
A metallic casing is designed to mesh with the shielded connector ...
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How did using the shield as signal return end up as a common practice in audio?
Or in short: was cost the only motivation? Because the major reason against this practice must have been already plain obvious in the mid of last century.
Namely, using the shield of a cable as signal ...
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USB C 2.0 Receptacle shield connection [duplicate]
I want to know if I should also connect the shield pin (Pin S1) in my schematic to GND or should I leave it not connected?
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Running and grounding paired shielded cable thru a connector
I need to run two logic signals around a vehicle, so for good measure, regardless if its overkill or not, I want to use a shielded single pair wire for that job. At one point it should be crimped to ...
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Common mode choke and grounding
How would you connect the cable shielding, metal enclosures and power ground on following system:
Since I had problems with noise before I wanted to add filtering on power input for "my PCB"...
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How to protect the signal quality of LVDT input and output?
I am designing a 6 wire LVDT. I need to know how to protect the signal quality of both the primary excitation input and secondary coil outputs inside the LVDT, and inside the device in which the LVDT ...
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Shielding AC magnetic field using cable shield connected to two grounds
I am currently reading a book about electromagnetic compatibility but I am confused about a section that talks about reducing the coupling between an external magnetic field \$ B_{ext}\$ and a circuit ...
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