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2 votes

My First PCB - EMI Problem on Poorly Earth Grounded Test Place

The input to the ADC is very high impedance and so it's relatively easy to inject noise into it. Look at the return path for the ADC trace, it's completely carved up by other traces, etc. There is ...
Robin Iddon's user avatar
0 votes

My First PCB - EMI Problem on Poorly Earth Grounded Test Place

Does noise appear between your GND and your chassis earth? (which is what I presume the earth symbol means that only connects to J7 pin 2) It is not connected to GND and it runs right round the board. ...
tirnasjimmy's user avatar
1 vote
Accepted

Trying to record from DIY op-amp results in seldom pops and clicks

Solved by using an Op Amp with EMIRR (EMI Rejection Rate). I used TL071 and the clicks were almost completely gone. P.S. OPA1641 didn't help at all, even though its EMIRR should be much higher. ...
Matilda Bentefor's user avatar
2 votes
Accepted

Ferrite bead on a SMPS output

First some notes: If your 24V load contains buck DC-DC converters to generate its internal power rails, or other noise makers like high current loads with PWM... it will generate a considerable amount ...
bobflux's user avatar
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0 votes

Ferrite bead on a SMPS output

A ferrite bead typically starts suppressing noise at frequencies >30MHz, whereas SMPSs typically operate at <1.5 MHz frequencies. Therefore a ferrite bead is not your first choice for noise ...
Stefan Wyss's user avatar
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1 vote

SDRAM logic makes noise on ADC readings with FPGA

A number of points, in no particular order. Points also drift arguably into meta topics, as FYI for interested readers who may have related questions. There doesn't seem a better venue to air these ...
Tim Williams's user avatar
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1 vote

Trying to record from DIY op-amp results in seldom pops and clicks

You have some spikes on the battery voltage as well! Can you think of some way to verify if the spikes are really there, in the analog signal? Such as, run the output into an active loudspeaker? You ...
frr's user avatar
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0 votes

Can bussed grounds in an audio patchbay create a ground loop?

There is endless debate on this subject and, in reality, no one true way. (OK perhaps there is, but variations in the way inputs and outputs of different pieces of gear are wired and connected/...
danmcb's user avatar
  • 6,889
1 vote

How to read ripple and noise on a linear power supply using RIGOL DS1202Z-e?

Technically, the connections are wired correctly, but the arrangement is poor. So like what you did, by connecting probe ground clip and scope tip to power supply ground and supply pins are correct. ...
Justme's user avatar
  • 144k
5 votes

Lots of electrical noise at boost converter output

If you look carefully at the Webench schematic, you'll see that you've ignored the specifications that were purposefully red-colored as being important :) You also should show a photo of how exactly ...
Kuba hasn't forgotten Monica's user avatar
14 votes

Lots of electrical noise at boost converter output

It's the output cap. According the the datasheet, C11 has maximum ripple current of 230mA RMS and 0.44 ohms impedance at 100kHz, some of this impedance is capacitive but the rest is 30-40 mOhms ESR. ...
bobflux's user avatar
  • 76k
20 votes

Lots of electrical noise at boost converter output

The diode is innocent. What you're seeing there is the effect of the output bulk capacitor's ESR (C11). According to the Digi-Key page you linked, its ESR is 0.44 Ohms. Given the waveform of the 1A ...
Jonathan S.'s user avatar
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1 vote

What is the safest and most noise free grounding method floating or non-floating for audio plugs & circuits on 2U aluminum case and SMPS

I solved the problem by getting rid of the switching power supply and went with a simple step-down transformer, full wave bridge and capacitor. Now It is noise free. I ended up floating the audio ...
Jim Dandy BOA's user avatar
0 votes

Noise in DC supply due to AC track nearby

The transformer isolates the mains ground with the circuit ground The common mode voltage of a single phase and neutral, with respect to ground, is (close to) one half of the differential voltage ...
Math Keeps Me Busy's user avatar
1 vote
Accepted

Unstable to do resistance measurements due to electric fans

Using shielded cables fixed the problem, I will include an image of the results when I collect enough data
Tino D's user avatar
  • 141
3 votes

SDRAM logic makes noise on ADC readings with FPGA

I have no timing constraints on ADC inputs, but does this toggling affect ADC timing? If you set no timing constraints, the FPGA synthetizer will assume these signals are not related to any clock (...
bobflux's user avatar
  • 76k
0 votes

Reduction of DC motor noise

Careful when PWM driving a brushed motor with any significant amounts of capacitance filtering. Popping capacitors across a brushed motor reduces noise from the motor, but to a fast PWM edge, those ...
Glenn Wardle's user avatar
3 votes
Accepted

Unknown signal source

These results are not unexpected at all. Nothing to do with the TV. Try it with charging bricks or other switching "brick" power supplies. it is unlike any switching noise I have seen ...
Kuba hasn't forgotten Monica's user avatar

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