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Questions tagged [pcb-design]

About designing the boards which carry the components of an electronic circuit. For questions about getting them built instead use PCB-fabrication. If your question is specific to a certain CAD tool, say which tool and version you are using.

-1
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0answers
30 views

Which microcontroller for homekit alarm system [on hold]

I have idea to build own PCB for alarm system which should handle following things: GSM (probably via SIM900 or Ai Thinker A6/A7) RFID (most likely external PCB) Keypad (via touch display) Homekit ...
0
votes
0answers
33 views

How to calculate stray capacitance on PCB

I use a 0.4mm spacing between PCB traces (including 0.4mm space between crystal pads and ground) and I believe that's causing stray capacitance. My circuit board is typical (1 ounce copper on FR4 ...
0
votes
1answer
78 views

How to measure this component

I want to know how to measure this components in the attached picture. If I'm right they are beads. The second one the brown one I thought at first that it is a capacitor but I can't measure its ...
2
votes
1answer
91 views

How to join and connect two wires in one connector point professionaly in a high voltage PCB?

Regarding a HV (6KV) PCB design there is a part of the circuitry related to reed relay connection. I have chosen a HV relay (datasheet) with flying lead connection in order to separate physically LV ...
0
votes
0answers
65 views

Tight Space Pin Remapping for General IC Controller Socket Design (3d Printer Main Board) [on hold]

I'm currently contemplating a 3d printer main board design... I would like to minimize price and maximize reliability and re usability. Existing boards use a somewhat monolithic architecture; Usually ...
26
votes
5answers
4k views

Why are GND pads often only connected by four traces? [duplicate]

I have seen this everywhere but cannot figure out why it would make sense to essentially compromise the quality of the ground connection. Is this done for visual reasons? Here is an example:
1
vote
4answers
126 views

What is the purpose of using the transistor in the circuit?

Current sensor using an instrumentation amplifier: Image source: Texas Instruments INA139, INA169 High-Side Measurement Current Shunt Monitor, Typical Application Circuit (datasheet page 1) Could ...
1
vote
1answer
44 views

Dotstar (APA102) LED strips decoupling capacitor on PCB

I am trying (based on very distant memories of EE in college) to design a fairly simple Arduino shield PCB to control several LED strips in parallel. Each strip would connect to its own 4 pin terminal ...
-2
votes
0answers
42 views

Tool for designing electrodes for PCB Mill Machine [closed]

I need to draw really simple layout, where i have only 2 electrodes and traces for them. Electrodes are 2x2 cm squares and i need traces to be thin like 0.15mm. I will need to create gcode from this ...
0
votes
0answers
43 views

“Solder PCB” or “Flying Lead” high voltage connection for a reed relay model?

I'm searching for the HV reed relay solution for channels multiplexing printed board design: V < 6KV, I < 10mA. 8 relays that connect 8 input pins to V or GND (given for an external supply ...
1
vote
3answers
100 views

Finding short-circuit across 3.3V power rail and ground rail on PCB

I have a short-circuit between my 3.3V and ground power rail on my assembled PCB. How do I find where the short is? Should I start by removing components one-by-one from the board?
0
votes
1answer
66 views

Distance between UART and I2C bus

I create a board with two bus: UART and I2C. Now I am expanding the connection terminal, which has the following contacts: RX / TX / SDA / SCL / + 5V / GND. The question is, do the I2C and UART buses ...
0
votes
0answers
49 views

Design an intel x86 motherboard for NAS [closed]

I'm interested in hiring for designing a motherboard for NAS. the primary requirements for such a motherboard are as follows: Intel J3455 or J4x05 CPU at least 4 Sata ports or higher Two * Gigabit ...
0
votes
1answer
42 views

Multiplexed LED column driver MOSFET doesn't fully turn off without a resistor parallel to the LEDS

I have a board with a 16x10 led matrix. The columns are switched with DMG9933 Dual P mosfets. The rows are driven with a constant current led driver ST STP16CPC26 (similar to TI TLC5956) I noticed ...
3
votes
1answer
132 views

Is there any advantage to using multiple tracks in this PCB design?

I'm fairly new to PCB designing, but I'm loving experimenting with it. Currently, I'm trying to develop a simple PWM circuit using MOSFETs to control an RGBW strip, using an Arduino with an integrated ...
4
votes
2answers
100 views

Strange shapes on the Wi-Fi module PCB

LG has this Wi-Fi module: This is a 2X2 Dual Band AC Wi-Fi / BT module. You will see two folded WiFi antennas on upper side and one bluetooth PCB trace antenna at the lower right side. I found this ...
2
votes
1answer
37 views

how to isolate coupled noise source in parasitic capacitance in high voltage pcb design?

I'm new designing a high/medium voltage (V <=10kV) with low voltage and low current (10mA). There will be only a few HV relays. Their coils will be triggered by LV. I have read some literature ...
0
votes
1answer
45 views

Where should I put my switch - on the enable of my SMPS or the power input?

I'm designing a simple board with a FitiPower FP6717 step-up converter chip (Datasheet) and a mechanical switch (SPDT) to enable or disable the output power. My design for the boost will be very close ...
0
votes
1answer
79 views

Is this an appropriate smps design? [closed]

I am an engineering fresh graduate with an interest in PCB design. I have been learning KiCAD which is really fun and I enjoy it alot. A friend came to me with the reference circuit attached here and ...
1
vote
0answers
55 views

Handling Hi voltage and very low current (10 mA) will need to prevent arc and corona effects on my PCB?

I' m following this guide; concretelly 3 and 4 chapters for High Voltage (HV) PCB design: https://www.magazines007.com/pdf/High-Voltage-PCDesign.pdf The fact is that I have read interesting ways to ...
1
vote
1answer
25 views

Via Template option is disabled

When I'm doing the connection, and I want to switch the layers (TOP to BOTTOM via Via), Altium automatically select some default values of Via size. I made my own Via Template, but the "Via Template" ...
1
vote
0answers
30 views

Altium: Rectangular clearance around rectangular pads

I am designing a high voltage PCB so I have created clearance rules between nets equal to the pad spacing on the high voltage capacitors (4.5 mm). When I pour polygons, Altium appears to produce ...
0
votes
2answers
27 views

What would prevent me from copying pads (or other components) in Altium?

I'm attempting to copy and paste several components from one Altium PCB to another. I would like to copy and paste all the components all at once, because they are mounting hardware for another PCB, ...
1
vote
2answers
64 views

A small PCB Stack Up for High Speed

I design 2 PCB's. They are connected with a connector. First one is PCB1, has the size of 50cmX10cm , the other one is PCB2 and has the size 2x5 cm. Through this pcbs and connectors some ...
0
votes
2answers
55 views

What specs does the “gros condo” (big capacitor) needs to have?

I have a pair of Dynaudio Air 20 at home. Unfortunately, the cable that used to control the speakers via RS232 died. I opened the cable, and saw that it was a customized RS-232 to TTL adapter, but ...
0
votes
1answer
143 views

How do I correctly protect my MCU from resetting during a current surge on RF transmission?

I designed a PCB with a SIM868 module for data transmission. On the PCB, the MCU resets randomly on transmission start of the SIM module. On a breadboard setup, it worked just fine, even without caps. ...
0
votes
1answer
43 views

Cold toner transfer for double sided PCB [on hold]

I am using acetone for transferring the toner to the PCB. The ink seems to adhere to the PCB but the tracks get blurred out and stick together. The tracks attach together and also the diameter of the ...
0
votes
2answers
52 views

PIC32 UART TX working perfectly RX not

I am using PIC32MM0064GPL028 to drive RGB+W LEDs via TLC57911 LED drivers. The idea is - data from python script -> Easysync USB to RS-485 -> ST485ECDR transceiver -> PIC32MM0064GPL028 -> TLC57911 -> ...
0
votes
1answer
43 views

What is the two-pin polarity indicator for a PCB? [duplicate]

I inserted a two-pin header (P1) into this circuit using EasyEDA. Does the square outline mean that is the positive pin, or is there another meaning?
0
votes
1answer
47 views

Reusing heatsink vias for ground plane connection

This a more elaborate phrasing of my previous question on the subject, which did not get much love. I would appreciate a clear and thorough answer since it is my last question (after a long journey) ...
1
vote
3answers
50 views

Connecting two nets in Eagle

I'm designing a schematic and board in Eagle 9.4.0. I have couple different power nets: signal 5V, power 5V (for servos) and power 8V (from battery). I'd like the power nets to be wider than others, ...
1
vote
0answers
45 views

Reason for stepped pins on M12 circular connector

I've been looking at M12 circular connectors for a project I'm working on (for example this one, drawing here), and I've noticed that many/all of them have stepped pins that create a 3mm or so offset/...
0
votes
0answers
60 views

Power line between data lines

I am finalizing my design which connects a USB Controller (FT601) with the FPGA (MachXO2). There is last thing I am not particularly happy about and I would like your feedback on that. In the ...
0
votes
1answer
42 views

Whats the purpose of the box in Proteus? [closed]

Like the title suggest, in Proteus 8, there is a box. why is it there? because we can simulate outside the box and it will work, so whats the purpose of the box ?
0
votes
0answers
14 views

How to perform parasitic extraction in CST Studio?

I'd like as the title suggests to perform a parasitic extraction of an inverter PCB design using PEEC Method in CST Studio Suite but, unfortunately I can't seem to find documentation or resources ...
1
vote
1answer
73 views

Heatsink pad connected to ground pins

Is it safe to use the exposed heatsink pad of a QFN to also connect the ground pins of the IC? (Like this question, but in my case the pad has many vias connecting it to ground plane.) Additionally, ...
1
vote
1answer
50 views

SIM800C-DS power supply schematic

I have drawn a circuit diagram of a power supply for a SIM800C-DS IC from the datasheet but is it right or wrong? I am confused as it's my first time. I also want to know where to connect the ...
1
vote
1answer
34 views

Eagle component has mixed tPlace and tDocu drawings

I'm designing a board with Eagle and I have placed some LEDs from the led library that comes with Eagle. With the default layers activated, the LED looks correct in the Board (the anode and cathode ...
6
votes
3answers
1k views

Decoupling cap routing on a 4 layer PCB

I would like to place some decoupling caps for an IC. The IC is on the top while the caps will be on the bottom, opposite side. How should I route them: A single VIA that connects the IC pin, power ...
4
votes
8answers
2k views

How can I add “standoffs” to elevate a SMD component above the PCB?

I made a mistake when creating a symbol/footprint for a small (2.0 x 1.6 mm) SMD crystal and didn't notice until the prototypes didn't work. Unfortunately, the boards are tiny and expensive (0.4 mm ...
1
vote
1answer
97 views

How do I read the dimensions to create a PCB footprint?

I'm trying to make a PCB footprint for the SSD1306 ribbon strip, and am unsure of the correct dimensions for the solder pads. The horizontal dimensions are clear enough but I don't know where the pads ...
0
votes
0answers
26 views

Highlighting feature of any net becomes latched on in Altium 17.1 PcbDocs

When routing a net, highlighting of startpoint/endpoints is great, but when a net I am no longer working on remains highlighted, it becomes an annoyance. This is happening multiple times a day and the ...
0
votes
1answer
58 views

PCB design rule errors, but can't understand why

I am trying to create a PCB using NI Ultiboard. My circuit is a SECPIC DC-DC converter and controlling the L1 current. This is my circuit: and I get this error: ...
1
vote
1answer
62 views

How to remove the noise on the video of the DС-DС converter?

I had to make my own DC-DC converter on the TPS54360 driver. But because of the driver for two cameras are very strong interference. I want to try to isolate the driver GND and design it with a track ...
0
votes
0answers
39 views

Move part to bottom layer without mirroring in Eagle

How can I move a SMD part in Eagle to the bottom layer without using mirror? The resulting PCB should have the SMD pads on the bottom layer but mirrored (if you turn the PCB and look on it from top ...
0
votes
2answers
114 views

What is the intended PCB layout for this Lumberg stereo connector?

I was intending to use the Lumberg 1503 02 3.5mm stereo jack connector on a PCB. After progressing some way through the design, I noticed that the pins for the connector are not on the bottom as I ...
5
votes
3answers
915 views

How to remove these lines in Altium Design

In my design, there are some lines with "=" on them. Can someone tell me why these lines appear and how to delete them? I'm using Altium18. Thank you.
1
vote
3answers
119 views

How do you know if impedance is the same for 2 ICs?

in my last question I got some very interesting answers that made rethink a lot about my design as to whether or not I need termination resistors at all. Additionally, the design proposed in this ...
0
votes
1answer
28 views

TO-72 package FET Case pin

I have 2N3823 JFETs in TO-72 package, which has 4 leads. No problems with Gate, Drain, and Source, but there is also a Case pin that I have been ignoring. Now I am putting together a PCB for a ...
3
votes
1answer
43 views

Keep out zone of microSD card set footprint

I'm designing a PCB with Hirose microSD card set DM3AT-SF-PEJM5. In its datasheet, page 3, there are several "no conductive traces" area, which are marked as "keep out" zone in the footprint I found. ...