Unanswered Questions
816 questions with no upvoted or accepted answers
5
votes
1
answer
1k
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Custom RP2040 PCB Not Detected by PC
I designed a custom RP2040 to control some 24V LED strips. The official hardware design guide from the Raspberry Pi Foundation is what I followed for my design. It was then sent out to JLCPCB for the ...
- 51
5
votes
0
answers
221
views
Invisible magic components that spoil the Eagle preview
You know, after the eagle board design is finished, you can see the card on the preview screen.
I'll show you two examples. There is no problem with one. The card is centered on the preview screen.
...
- 1
4
votes
0
answers
97
views
Microstrip PCB Design
I am designing a microstrip PCB with frequencies ranging from 100MHz to 8GHz.
There are no significant issues at lower frequencies, but the signal loss becomes quite high as approaching 8GHz.
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4
votes
0
answers
59
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Attempting to patch the "G75 Bug" on a Gerber Level
Context
I am currently looking for alternative PCB manufacturers for my company and have sent Gerber files to some (Chinese) companies.
These Gerber files have already been used in the past by various ...
- 2,803
4
votes
0
answers
2k
views
Capacitive touch sensor design
I made a PCB with several capacitive pads to be read by IQS127.
They work, but any material I put close to the PCB surface will trigger the output, even the 8 mm glass I'm going to use.
The pads ...
- 1,235
4
votes
0
answers
124
views
LM4510 Switching Converter not working
I am using a TI LM4510 converter (datasheet) to step up from 5V to 12V (adjustable). I have good input power, enabled chip, and followed datasheet, but the output voltage is actually lower than the ...
- 17.9k
4
votes
0
answers
1k
views
Qi Receiver on PCB
I'm looking at implementing Qi charging in my project, would it be possible to have a Qi receiver directly on the back of the PCB (copper traces in the shape of a coil)? Could this interfere with the ...
CommunityBot
- 1
3
votes
1
answer
205
views
Ethernet controller EMC failure
I designed my very first Fast Ethernet PCB and it is having a hard time passing Radiated Emissions.
The result came back from the test lab shows that it is radiating strongly at 125 MHz:
In the ...
CommunityBot
- 1
3
votes
0
answers
47
views
How to verify if SDRAM alternative is a direct drop in replacement?
I'm trying to verify whether the two SDRAM chips are complete drop in replacements of each other. I've verified the footprint, electrical characteristics and various timing parameters (namely CL, tRCD,...
- 51
3
votes
0
answers
289
views
How to find rise/fall time of SPI?
I want to calculate the frequency of the SPI2 line of the STM32L073 chip. I downloaded the STM32L073 ISB file. I followed these steps while doing the calculations.
For example I wanted to look at the ...
- 7,959
3
votes
0
answers
276
views
DDR Trace Length in Motherboards
I was trying to understand DDR, Trace-length, and signal integrity.
Most of the datasheets, For example, iMX8M Mini (Doc: IMX8MMHDG) clearly specifies what are the requirements for the each signal in ...
3
votes
0
answers
102
views
How to handle deleted components in PCB layout
I am trying to "update" an Altium project; deleting 3 sheets with all components and adding 2 sheets. I completed the schematics and next step is layout.
As I deleted components, I saw so ...
- 9,270
3
votes
0
answers
368
views
Esp32 rf design review
Preamble: this is the first time I'm working in rf circuit design, I went simple and I hope I didn't make any silly mistakes, but I still have some doubts.
I am currently designing a garden programmer ...
- 195
3
votes
0
answers
59
views
Does through-hole mounting have an advantage over surface mounting in sub-zero temperatures?
I am working on a device that I want to work outdoors far up north (e.g. on a farm), maybe down to -40C. I read a lot about through-hole circuit boards being more resistant to environmental stress ...
- 572
3
votes
0
answers
349
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Enclosure/boxes for high voltage PCB
It is time to choose the proper enclosure for a high voltage PCB. We will need to do holes for LV external connectors and external connectors for high voltage wires. I was looking for standard boxes ...
- 851