Skip to main content

Questions tagged [pcb]

PCB is the acronym to Printed Circuit Board. A PCB is a carrier for the circuit's components and their electrical connections.

Filter by
Sorted by
Tagged with
0 votes
1 answer
42 views

Does DDR3 master clock need to be longest trace in general?

I'm working on my first PCB which incorporates DDR3L memory with an STM32MP157AAB3 processor. I've been following ST's DDR3 guide from AN5122 and I came across something which I found odd and which my ...
Swiss Gnome's user avatar
0 votes
2 answers
62 views

Treating an STM32 MCU's unused pins and reset state

I'm using this MCU from STM2 on a board and the PCB layout is as follows: I will not use several MCU pins, so they are disconnected as shown above(pin 6, 7, 8, 11, 12 ect.). Also I cannot do any ...
pnatk's user avatar
  • 1,448
0 votes
0 answers
29 views

Controlling a device in a car using a button and ignition

I need to connect a device to my car. I thought about using an XOR gate because: A - button B - car ignition. If the car's ignition is off (0), pressing the button (1) will turn on the device (1). If ...
jminhal's user avatar
  • 21
0 votes
0 answers
36 views

How to short time delay controller?

I have an old keyboard which I use for decorative purpose. It has RGB lights which turns on for few seconds when a key is pressed. I want to keep them on at all times. How to achieve this? Can I ...
Saransh Bairagi's user avatar
0 votes
0 answers
37 views

TCA9548A I2C Python coding help

I am designing a board using 4 TCA9548As that each have 8 screw terminals so that I can connect to 32 addressable devices. I am trying to create the python code to be able to write to each of these ...
Beau Raley's user avatar
0 votes
1 answer
79 views

Is the wiring of this STM32 minimal system acceptable?

This is a question about the optimal routing for an STM minimal system. I made a minimal system board using the STM32H563VIT6. Is the routing method shown in the upper section, where I aim to connect ...
Antron Mack's user avatar
1 vote
2 answers
37 views

RF Microstrip trace polygon

I'm designing a board with an RF L-band trace (around 2.150GHz) on the top layer side. I have a clear and unbroken ground plane on the bottom layer of the trace. However, I'm curious to know whether ...
mehrad aghaei's user avatar
12 votes
4 answers
3k views

Pattern on a PCB

I've never worked on power supplies. What is the purpose of the pattern in this image (yellow) ? I don't have this PCB, I only have this photo.
Vincent's user avatar
  • 1,284
1 vote
0 answers
38 views

Remove Unused Pad/ Via

I want to make remove unused pad/via at inner layer in order to increase area. But I wonder that does it cause problems in terms of IPC Class-III or PCB manufacturing?
123's user avatar
  • 11
0 votes
0 answers
42 views

How can I cut a PCB in half and shift all traces, vias, components, shapes in Cadence Allegro PCB?

I'm fairly new to Cadence Allegro. I need to extend a board in the X direction. How can I select everything in all layers (outline, traces, shapes, vias, components) and move/offset in the X direction?...
oolong tea's user avatar
4 votes
1 answer
642 views

Need help identifying component with 'T4 G4' markings

I need help with identifying a Yaskawa Z1000 board component (T4 G4 markings on):
user388390's user avatar
0 votes
1 answer
33 views

Could I use a linkstyle momentary dpdt switch?

This is a switch from my cars sunroof. It is a Lincoln Town Car so the part is Ford. I need to replace this switch and I am wondering if I can just get a linkstyle dpdt switch and solder these four ...
ConnerWithAnE's user avatar
1 vote
3 answers
50 views

How do I generate a trigger signal from a periodic analog signal having varying amplitude [closed]

I have an analog signal detecting a periodic vibration of low frequency (<100Hz) and want to generate a pulse whenever the signal crosses a certain threshold. The challenge is that the amplitude of ...
bosie's user avatar
  • 11
4 votes
2 answers
916 views

Why does IPC 2221 require so much more spacing at elevation?

In the IPC 2221 is a table that specifies the required trace spacing. One thing that I find very surprising is the jump once the elevation is above 3050m. E.g. For an external conductor (uncoated) at ...
Lucas's user avatar
  • 525
0 votes
0 answers
50 views

Options after breaking USB-C jack off of PCB

Hello! Snapped the USB-C jack off of my Logitech MX Keys. I have a background in computer engineering and some experience doing board-level repairs. I do have an SMD hotplate, multiple soldering ...
Mikey's user avatar
  • 1
1 vote
2 answers
96 views

custom PCB design for UART-TTL to STM32

I have a project where I am using an stm32f103c8t6 to send a 10Hz pulse (as a hard trigger for a camera) and sends data through UART to a connected computer. I'm using this opportunity to learn PCB ...
jeb2's user avatar
  • 111
4 votes
6 answers
931 views

Attaching foam to the bottom of a PCB

I'm currently designing some development boards that are quite large, around 100x180mm, with lots of through-hole components. The goal is to create an educational tool for students. Because of this, I ...
Rede6866's user avatar
2 votes
1 answer
88 views

PCB design review (Altium)

I have recently designed my first PCB using Altium and I am seeking feedback on it. the PCB stack-up is 4 layers (signal, GND, GND, signal). The PCB includes various components such as a STM32, 3.3 V ...
Soliman's user avatar
  • 23
0 votes
0 answers
62 views

Since JTAG can be authenticated and encrypted, which key is used? I read that Secure Boot is used, but what is the key? [closed]

Since JTAG can be authenticated and encrypted, which key is used? I read that Secure Boot is used, but what is the key? Me, owner of this laptop, how can I know the key to use to access my own laptop ...
allexj's user avatar
  • 53
1 vote
4 answers
135 views

74HC595 behaves randomly, need help with my circuit

I'm trying to make a Nixie clock based on an ESP32. I've made a working prototype on a breadboard. Only the 74HC595 part, which is where the problem is at: I then made a PCB: After soldering ...
TakeHere's user avatar
2 votes
3 answers
167 views

Source impedance-trace impedance - load termination impedance confusion

I drew an experiment PCB to better understand the PCB impedance. And when I look at the impedance at 1 GHz, it can be seen that it is 119 Ω at most points of the trace. Then, I created a source that ...
Electronx's user avatar
  • 756
1 vote
2 answers
130 views

Will such a scheme work correctly with ATmega328PB?

I am developing a small on-board computer for my rocket model and now I have designed the ATmega328PB connection to the CH340G and I want to ask if there are any errors in the connection and if there ...
DYNAMIC AEROSPACE's user avatar
0 votes
1 answer
52 views

Can heat sinks and/or heat pipes be retrofitted onto an existing electronic device?

I have a USB hub that is going into an additional enclosure that is fairly airtight. This USB hub is only rated for 0C to 40C operational, however it will need to survive hotter and colder ...
RoyGBivJr's user avatar
0 votes
2 answers
61 views

Testing to find polarity of PCB power connector

I've got a PCB I ordered from China. It required a 5V input voltage through a barrel jack. The issue is there is no sign showing the polarity (positive or negative center) so I don't want to connect ...
Eokun's user avatar
  • 13
0 votes
0 answers
47 views

How to add text on PCB Pads?

How to add text on PCB Pads in Altium Designer I just this Image Im Interest to known how to do this
Monesh Rathod's user avatar
0 votes
0 answers
92 views

Review a simple schematics

Hello everyone I hope you are well! I finished my schematics and need a quick review (I would be grateful for the insights). The board has the following: ATTiny 1616 as the MCU (https://ww1.microchip....
Tahoor Asim's user avatar
2 votes
1 answer
72 views

What are top and bottom copper types in KiCAD used for?

Being at very beginner level in PCB design and in KiCAD I have bene using the following F.Cu and B.Cu settings for a two layer board: In my case, I have most of the traces on the bottom side and a ...
user1245's user avatar
  • 4,301
0 votes
0 answers
19 views

CPU to Switch SGMII port with PCIE 2.5Gb

I can't seem to find a 2.5 Gbps Ethernet controller that could be a bridge between the SGMII+ port and PCIe. this is what I want to do: I don't want to use PHY (from the copper 2.5G to 2.5G SGMII) ...
Knowledge's user avatar
  • 441
3 votes
1 answer
104 views

Help identifying hollow spring / inverted header sockets

I'm trying to identify the following hollow sockets which are used to interface with a 0.1" pitched header: (source: US Digital PC5 Broadcom/Avago Compatible Incremental Encoder Cable Driver. ...
JorisL's user avatar
  • 33
1 vote
1 answer
106 views

Request for Review: First PCB Design - Feedback on Potential Issues or Missing Elements

I have recently designed my first PCB and I am seeking feedback on it to ensure there are no errors or missing elements. I have attached the schematic of my design. The PCB includes various components ...
noor aldine's user avatar
2 votes
1 answer
54 views

Unknown SMD Component LP 27 L#

I'm trying to identify and find analog for the smd component on a PCB. The PCB is a an engine control unit from Mersedes W168. The unknown component is a 2-pin polar component in the red circle. The ...
iu-m's user avatar
  • 23
0 votes
1 answer
40 views

Matlab simulation of PCB IFA

I am designing a PCB IFA and to get used to simulating it later down the road, I decided to first simulate an existing, known working design. Known design for 0.062" Substrate (page 3) This is ...
JonathanG's user avatar
  • 444
0 votes
1 answer
36 views

Altium annotation - no changes were made

Although I have made changes in the schematic file in Altium, it tells me that there is no change in the annotation process, but there is. What is this caused by, and how to solve it?
ertugruldugencioglu's user avatar
2 votes
1 answer
195 views

SEPIC DC-DC converter

I want to do the layout for a SEPIC DC/DC converter as follows: In the datasheet of the driver LM3488, they have recommendation for layout, which means the traces should be as short as possible for ...
Andromeda's user avatar
  • 473
0 votes
1 answer
42 views

What should I do when clearance boundaries overlap with SMD pins?

I am brand new to layout design. I am using the TPS62136RGXR buck converter in my design. However, according to the attached image, the pin's clearance boundaries (0.2mm according to JLCPCB's assembly ...
NickRand's user avatar
0 votes
1 answer
39 views

Choosing trace width and spacing

What is the standard for choosing trace width and spacing? I keep finding various and different answers. My goal is to go as small as possible for my board. Everything is low current; nothing should ...
user373900's user avatar
3 votes
1 answer
53 views

Cadance to Altium Conversion - Is it Hard?

Does anyone know how much work is required to convert Cadence PCB design files to Altium importable files? I've been told it's the equivalent of 2-3 months of work. I'm slightly dubious but I'm ...
Lpaulson's user avatar
  • 305
1 vote
0 answers
38 views

Battery Management System review [closed]

I am posting a schematic design of Battery Management System can someone help me or tell me in finding whether this design is correct or not and will it work
Rohan Sharia's user avatar
1 vote
2 answers
106 views

How do I modulate the output power of a laser diode at 1 kHz? [closed]

I am planning to use L785P5 laser diode from Thorlabs, which has a maximum output power of 5 mW. As per my requirement, I need power output in the range of 0-100 µW. So how do I go about reducing the ...
solitude_surfer's user avatar
0 votes
2 answers
148 views

What is the purpose of this circuit inside a solar lamp?

I'm trying to get started with electronics, just as a side quest. I found this little circuit inside a solar lamp I had. I'm trying to understand what its purpose is and why it uses its components, ...
Jeremy D'Souza's user avatar
1 vote
0 answers
41 views

How to test Keychron K3 Pro PCB LEDs

After plugging Keychron K3 Pro keyboard to USB port on Tesmart KVM switch (used not original power adapter maybe it worked not stable), after 10 min of working keyboard and mouse unplugged and light ...
Lion's user avatar
  • 11
3 votes
2 answers
47 views

Ground plane for SMPS EMI-Filter?

I am designing a board including various switch mode power supplies, e.g. Buck, boost, and so on. The application notes recommend using split ground planes for power and analog parts, however after ...
BenK's user avatar
  • 167
3 votes
1 answer
189 views

LM2675 outputs wrong voltage, not sure about layout

I'm making an ESP32 board to control some 12V outputs, so I got an LM2675-3.3 buck converter IC (datasheet) to power the MCU. This is my first time designing and soldering a PCB and I'm guessing I may ...
Axl Vang's user avatar
1 vote
0 answers
64 views

PCB digital sound input and output

I've designed a simple 3-band equalizer circuit. I've used 3.5 mm audio input connected with computer via 3.5 mm audio jack for input, and basic small speaker for output. In all my references, many ...
GL Park's user avatar
  • 31
1 vote
1 answer
50 views

How to deal with routing of distributed signals

How to connect some signals that have many branches, such as SPI & I2C, such as clock? Does it have any special principles and methods? I have read some things, but my information is incomplete.
hossein hamzekhani's user avatar
2 votes
0 answers
33 views

Question re: layout and grounding of a PCB with SPI-controlled H-bridges and load switches

My question is regarding the layout, and in particular the grounding, of a PCB that has a microcontroller that controls various H-bridge drivers (that will be PWM’d) and load switches via SPI. The ...
Mark512's user avatar
  • 21
5 votes
3 answers
1k views

Do all crystals need capacitors?

I'm trying to make a pcb. I've seen this reference board from Figure 34. XTAL positioning of ST an5165 where they didn't add any capacitors to the HSE nx2016 crystal. Why? I tried to look on ...
Abderraouf Khellas's user avatar
1 vote
1 answer
55 views

Matching SMD footprints to transmission line track width

I created a simple transmission line on a PCB (coplanar waveguide) between two SMA connectors. I obtained the track width based on JLCPCB's Impedance calculator for the 7628 stackup. The track width ...
Hikikomori's user avatar
3 votes
1 answer
117 views

How can I locate via holes for PCB design?

I'm working on a PCB design (Artwork) and looking at the reference PCB layout for the EP4RKU+ (1-to-4 splitter), I see via holes overlapping with the GND pads. However, the PCB design (Artwork) guy ...
Artelec's user avatar
  • 71
1 vote
1 answer
83 views

Can PE and GND be the same for HY2112 to Function?

If C1 is connected to GND instead of PE, will the HY2112 device fail to disconnect the battery? My understanding is that HY2112 (similar to DW01A) measures cell current using R2 as a shunt. If OC for ...
sdolan's user avatar
  • 113

1
2 3 4 5
123