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.

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4
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2answers
474 views

Does the distance between the signal lines (in terms of noise immunity) matter when wiring the board?

Studying the design of many boards, I noticed that the signal lines go very close to each other. A small distance between the tracks improves noise immunity or is it a matter of beauty and ...
2
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1answer
70 views

EAGLE - VIAS are smaller on the screen than in the actual gerber

Hi I have upgraded EAGLE to 9.5 and have one quite serious issue. The VIAS are displayed smaller than in the actual gerber file or manufacturing preview. Do you know the option which will force Eagle ...
25
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2answers
3k views

What's the meaning of Electrical Inches?

I was reading a PCB design notes and guidelines from Xilinx for their 7 series FPGAs and came across this sentence: The capacitors should be placed as close as possible to the FPGA. Any placement ...
1
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2answers
109 views

How can I layout these regulators to minimize board size and EMI?

I have three switching regulators. A 12V, 5V(green box), and 48V(purple box). The plan is to supply both regulators through -/+12vout pours. If I am trying to minimize board size while also ...
0
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0answers
25 views

Linking Attributes/Parameters in Altium Designer PCB

I have a test board with one unplated through hole pad and a string that needs to say the diameter of the hole in the top copper layer as shown: I would like to link the hole size and the value in ...
0
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0answers
14 views

Termination mode for CoolRunner CPLD (XC2C32A)

Fitting properties in Xilinx ISE offers some options for -unused and -terminate: ...
0
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1answer
37 views

Create open copper plane in EAGLE

I need to redesign an old PCB and for that I want to put down a open copper plane that won't get covered by solder mask. I tried it by creating a rectangle in the 'Pads'-Layer. The PCBs just arrived ...
1
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2answers
91 views

PCB: ground plane thermals (in Eagle)

In a previous iteration of a PCB layout, I added a ground plane fill as recommended by many tutorials online (eg Sparkfun). By default Eagle creates thermals to ease soldering to the ground plane, but ...
0
votes
1answer
70 views

Do I need external pull up resistors for TX and RX lines in CP2102N?

I want to use it to program a microcontroller and this is the recommended set up from the data sheet. I was wonder If I need these resistors or not. I am not asking if STM32 chips require pull ups. ...
3
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3answers
123 views

PCB design for 50MHz

I'm designing a rather big PCB which will have 64 nokia 5110 LCDs arranged in an 8x8 matrix and will all be controlled by a single microcontroller. Each screen will have an 8-bit shift register as a ...
0
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4answers
153 views

Designing a PCB with variable-sized component alternatives

I'd like to get a little PCB manufactured with a basic circuit that I can populate with components of various sizes. E.g. have a place where any of a range of possible capacitor sizes could go. So I ...
0
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1answer
57 views

Version control system for KiCAD which can deal with merge requests

When working on a project with a group of people it is often required to merge changes someone else has made into a master version of the project. However my EDA of chocie, KiCAD, does not seem to ...
0
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1answer
31 views

PWM low frequency generation low current draw

I'm a mechanical engineer with the work assignment to develop a low current draw PCB to control a servo mechanism. The device must work on two 9 volt batteries in series (the device must deliver an 18 ...
1
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1answer
21 views

Eagle: Alternative to Pinswap for GPIO expander

I'm working on a PCB which is basically multiple MCP23017 GPIO expanders driven from I2C. As I layout the board (in EAGLE), I frequently find places where using different IO pins would avoid vias and ...
1
vote
1answer
66 views

Ground Plane Layout for Power Supply on PCB

I'm in the process of designing my first PCB. For the power supply, I have a 4.5V battery pack fed into a voltage regulator that outputs 3.3V. This section of the PCB and governing schematic are shown ...
1
vote
1answer
68 views

Where do I find those AC mains connectors?

I am currently designing a "smart" power strip for aquariums and cant find an PCB mounted wall outlet connector like the image shows, it would be used to connect the load and not for powering the ...
1
vote
1answer
60 views

Why footprint dimensions are to edges and not centers

Whenever I'm looking at electronic components, I regularly see footprints with this kind of thing: Dimension E seems to me to be somewhat unhelpful; rather than simply reading the centre distance (...
1
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1answer
59 views

How to place through solder pads of different shapes in EAGLE?

I searched everywhere and watched many eagle tutorials, but I couldn't find out how to place circle and square through hole solder pads. In the Eagle parts list, I only found the octagon solder pad. ...
0
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2answers
48 views

When making power polygon , making polygon on the smd-pad has any problems?

I'm now making 4 layer PCB and my PCB has one Power plane (L3) and one GND plane (L2). Now I just make a connection with inner layer (L3) with Top plane(L1). At this point, I'm curious that what is ...
0
votes
1answer
79 views

PCB strip from manufacturer

When we manufacture certain PCBs, where 50ohms impedance matching is required the manufacturer provides a small PCB strip along with the actual PCB. What is the actual purpose of this?
1
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4answers
63 views

Does placing additional capacitors in parallel with CJ7805 affect its performance?

I'm not sure if this is a stupid question, but I'd still prefer to ask than regret it later. I'm designing a PCB with the CJ7805 which, like the LM7805, can supply a steady 5 volts. In this case, it's ...
0
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0answers
20 views

How do I design a circuit with overload and shortcircuit protection for a multi-usb type c powered hub only?

I am planning on getting a number of raspberry pi 4, for now we will say room for 5. They have usb type c connectors on them, and can receive 5v at 5 amps. Therefore the total amps is 5 ports * 5a ...
84
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6answers
6k views

Looking for circuit board material that can be dissolved

We are working on a product where the entire device needs to be dissolved in liquid after the device has operated and the device is no longer usable or desired. This is a down-hole application. The ...
1
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3answers
99 views

How to keep PWM from “contaminating” analog read values on my pcb

So I'm designing a PCB for a MIDI controller with a lot of slide potentiometers and push buttons. I'm also backlighting the pushbuttons with LEDs running on PWM and I'm worried that the PWM for the ...
0
votes
1answer
53 views

Serpentine PCB heater size calculation

So, I'm kinda new to the field and the time has come to design my first PCB heater. The main concept is to drive it using a Raspberry Pi and a temperature sensor as feedback. Here is the whole ...
0
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2answers
87 views

AGND VS DGND on PCB?

Could someone please tell me the difference between analog ground and digital ground on pcb? It would be easier if you explained it with a example!
2
votes
1answer
63 views

What is a sufficient way to ground my 2 layer low frequency PCB inside a housing?

I'm designing a simple PCB for GPS signal control. The frequency is below 5Hz, supply voltage is 9V and converted to 5V. This print will be screwed in a plastic housing with four M3 mounting holes at ...
1
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1answer
76 views

Sanity check: Routing high current traces (MOSFET relay circuit for 300W heater)?

This is the first time I've ever designed a power PCB/ a PCB that needed to take a high current, I'm looking to check that I'm doing this right and for any advice on how to improve? details below. I'...
1
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1answer
172 views

Can I swap TX+ and TX- (and RX+ and RX- ) using ethernet magnetics?

I am building ethernet connectors and a switch into a product. There is a requirement to include PoE which I haven't done before. This has required the use of a new magnetics chip to expose the two ...
0
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0answers
44 views

RF sampling ADCs(ADC12DJ3200 ),PLLS and regulators placement and layout

I am novice in PCB component placement and layout. I have just started my career in Hardware design. We have designed a schematic for Data Acquisition System. In our design, we are using three RF ...
0
votes
1answer
137 views

Can resistive traces be created on a PCB?

I'm assuming that copper traces on a PCB have negligible resistance. Is it possible to put a trace on a PCB that has some greater amount of resistance? The amount of resistance would not need to be ...
0
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0answers
11 views

EP53F8QI Short to GND fault

We have a design with an EP53F8QI that multiple ICs have been burned both at room temperature and +80 °.C. We are using it to create a +3.3V and on fault we have found that the +3.3V supply is shorted ...
0
votes
1answer
83 views

Placement of the microcontroller on the back of the board with LEDs

I am designing a board with 9 SK6812 LEDs. On the back of the board I want to place the Atmega328P microcontroller. I have doubts whether the heating of the LED can affect the operation of the ...
0
votes
1answer
39 views

EAGLE - StopMask DRC Error

I cant understand what this DRC error means. Especially I do not understand this box. Does it mean that the Soldermask will cover part of the pad? How to correct it?
0
votes
1answer
67 views

Are there any issues with placing castellations on corners of a PCB

I've had a request from a client for a PCB design with castellations on the corners of the board. The board is not actually rectangular, so the corners are not right-angles but more like this: I'd ...
1
vote
3answers
142 views

PCB routing around capacitors “snake style” possible electric disadvantages?

Is there any reason not to route the +12V and GND lines in a snaking pattern as shown with C7 + C11? From instinct I'd always route caps in parallel to power and gnd rails. Top left near D1 is the ...
9
votes
3answers
2k views

Design of 50 ohms RF trace for 2.4GHz…Double layer FR-4 PCB

I will use a 2.4GHz transceiver on my new project. The PCB material will be FR-4 with 1.6mm thickness and the connector is a SMA. My doubt is about the RF trace that should have 50 ohms impedance. ...
2
votes
4answers
68 views

Longer digital trace further from analog vs shorter digital trace closer to analog

In the 4 layer PCB below (top layer) what is better in terms of interference with the analog circuitry on the lower left (current sense amp and buffer op-amp) trace 1 or 2? The FPGA does have bypass ...
1
vote
1answer
59 views

Altium - Invisible unrouted nets/components?

I've got a design in Altium and while routing, I moved a few resistors. They somehow accidentally got deleted and wouldn't undelete. I brought them back with an ECO, and placed them where I want them. ...
0
votes
0answers
33 views

How to use ESP-WROOM-32 to send wireless TX and RX commands from a PIC?

I want to have the possibility to send the commands of a PIC in a way that it's wireless and I thought it would be a good idea to use a ESP WROOM 32. In the datasheet it has the following schematic: ...
7
votes
4answers
2k views

Can copper pour be used as an alternative to large traces?

This is a general question, but if I am designing a PCB that needs a trace width of 110 mil, would I be able to use the copper pour instead of drawing out the large trace? The reason I am asking is ...
2
votes
5answers
246 views

Review PCB Design

I've created a PCB design for the first time ever, but I would like to know if I've made any mistakes that will result in a broken board or short circuits in the near future. I've encountered people ...
0
votes
1answer
53 views

Optimum placement, PCB routing for bypass/decoupling capacitors and ground loops

I've seen various answers regarding routing of decaps, wondering which method is optimum for better power distribution and noise immunity: Another question is, will this routing cause ground loops? I ...
1
vote
4answers
171 views

Does this connector exist and if so what is the correct name?

Please see picture. 2.54mm pin pitch. 8 pins, 8 'ways'. So, "1x8" I think is the right way to state it? I am trying to find a connector / header / whatever-name-is-correct to change direction 90 ...
1
vote
1answer
74 views

High current over 5V on PCB panes instead of track

I have leds running for around 600 Watts of 5V leds (120 amps). The source of the power are three 48V to 5V converters which each can handle 200 watts. If I would run this amount of Amps over my PCB ...
0
votes
1answer
118 views

High Voltage on PCBs: design and layout questions

I am designing a PCB that has high voltage (DC) on it. It will be located on a CubeSat (so, space). The PCB (HV-PCB) will receive the HV (3 kV max) from a DC-DC converter through a Coax cable; the ...
0
votes
1answer
98 views

Advice on battery powered ESP32 with NFC Design

I'm new to PCB design (First one) and I want some advice and tips from more knowledgeable people in regard to basic design elements and especially the power consumption part. I want to make the ...
0
votes
1answer
84 views

KiCad problem, schematic to PCB layout generates empty PCBnew window

I am using KiCad 5.0.0, after I built my schematic I annotated schematic symbols, assigned PCB footprints to the schematic symbols, then generated the netlist, and finally when I clicked on the tab of ...
1
vote
1answer
47 views

should land patterns match the typical or the maximum part footprint dimension?

I've read that for QFN packages at least, the width of the pads on the board should exactly match the width of the feet on the bottom of the chip. However, the datasheet for the part I'm working with ...
0
votes
1answer
40 views

Non-shortest path traces [duplicate]

Inside a Nintendo Switch I spotted some traces that take a meandering path to the RAM chips. What are the benefits of designing it this way, instead of taking the shortest path?