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.

229 questions with no upvoted or accepted answers
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125 views

First PCB project design critique requested (RF) EDITED

This is my first ever RF PCB project and it'd be great to receive some guidance to make this project 'first-time-right'. It's purpose is to transmit and receive signals at two different frequencies: ...
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69 views

How do you plan and check if a device will be compatible with every other device it will encounter in the field?

Hello I have a question that hopefully I can clearly state my question well enough. I work in television broadcasting and simply take off the shelf converters that take various signals and convert ...
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1answer
155 views

5V Switching Regulator Problems

I have a circuit with two supplies. A 19v supply for stepper motors, and a 5v supply for driving the ATMEGA644, 3 stepper motor driver daughter boards, a bluetooth LE daughter board, and 2 ws2812b rgb ...
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51 views

Strange powerplane layering issue in designspark

I'm trying to order a 6 layer PCB from a fab but they are asking me to resolve an issue with the file and I'm a bit stumped on what to do about it. The second layer of the design I have designated as ...
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85 views

Routing the main power supply across a PCB and choosing vias for it

I have a board that uses several different switching converters with 33uH ferrite beads that take up a fair amount of space. I'd originally intended to keep them all at the top of the board (not top ...
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1answer
168 views

ISA Card Mechanical Drawing Source

I'm designing a new ISA form factor PC board for a legacy system. I've looked around the net and found several references for ISA board dimensions, but they don't call out the location of the edge ...
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1answer
55 views

Acceptable Buck Converter Output

I've just put together my first busk converter with a LMR16006Y-Q1. http://www.ti.com/lit/ds/symlink/lmr16006y-q1.pdf Here is what it looks like on the scope. The Pink signal is unloaded, the other ...
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116 views

Reversed silk screening on EasyEDA

Just a quick one. I'm not sure if the text should be mirrored on the bottom layer of EasyEDA. It seems okay in the 3D preview, but when I upload the gerber to JLC their preview shows it still reversed....
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1answer
79 views

Accidentally Pasted Beyond Origin in Altium

I'm new in Altium and I accidentally pasted some pads and components(the ones at the bottom corner) from another pcb file but I wasn't aware of it at first because it didn't show on the sheet on the ...
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1answer
296 views

ATMega32u4 VBUS and SMD Schottky Diode

I have spent quite a bit of time trying to work this out, but I just can't. I want to power my ATMEGA32U4 chip via USB, and at the same time send that USB +5V off to the circuit +5V bus per the ...
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483 views

Custom Arduino powered board (CH340C) Serial Problem

I made this custom board that contains a complete arduino nano on it. I soldered every component with extreme care and already check all the connections and they all go according to the designed ...
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155 views

Put the crystal on the bottom with thru-vias, or on the top with a blind via?

I'm using an STM32L155 in a very small (0.4 mm pitch) WLCSP package (6x9 array). At this scale there is no room for traces between the balls, so the design requires HDI and/or blind vias to fanout the ...
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301 views

Faulty H-Bridge Design L9110s

I am trying to integrate a dual h-bridge design in to my custom PCB (Arduino Nano with integrated motor driver) using the L9110s IC. However, I am struggling to get it working properly. The h-bridge ...
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166 views

4 layer board stack-up and some question related to power layer

I've got some questions regarding my stack-up and power layer, which is layer 3 on my PCB. But before I ask my question I will describe my PCB. Most components are SMD parts (capacitors etc.). Top ...
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2k views

Metal Detector using IC 555 Timer project

I want to build some project about metal detector using integrated circuit 555 timer. I already made a schematic in proteus 8 application. I made some change with the original schematic i found on ...
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1answer
209 views

How to query wires that are connected to selected component in Altium Designer?

I want to apply special rule only to components with myFootprint and all connected wires to it. AD can select all components with that footprint with this query HasFootprint('myFootprint'). I also ...
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196 views

Has anyone ever seen this transmission line setup (double series terminated)?

I am designing a custom PCB interface to be used with some off-the-shelf devices. The relevant off-the-shelf interface they provide is cumbersome and doesn't fit my application, so I am designing my ...
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365 views

Most cost effective 6 layer stack setup?

I've been trying to come up with a 6 layer PCB layout with microvias. But I cannot think of a cost optimized layer stack, because every manufacturer seems to tell me something different on their ...
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2answers
41 views

While performing the controlled impedance routing what about the current flowing through it?

While calculating the conductor impedance the parameters that we consider are the conductor width, conductor thickness, frequency & substrate parameters. For achieving the particular impedance ...
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108 views

ESD (and EMI) protect long slow lines

I'm designing a measurement and control board to interface with an old (70s) PLC. The board consists mainly of I/O ports, both analog and digital in- and outputs. To have my boards not fried by the ...
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68 views

Large full planes, or moated sections, which is more quiet?

Take a six layer PCB with lots of circuitry, smaller than you'd like, parts on both sides, with very sensitive amplifiers looking for RF signals in the 100nV range, and digital circuitry. Top layer, ...
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97 views

What can I do to avoid impedance discontinuity when high-speed signal bifurcates on PCB?

As mentioned before, I want to supply two PCBs with same-frequency clock(as high as 10GHz).But now there is only one pair of differential clock, while both of the PCBs need one. So I am thinking of ...
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1k views

Coppers Pours for 4-Layer RF (433MHz) Board?

I've got a 4-layer prototype transmitter board built that is using a low-speed MCU (2 MHz). The critical RF sections are 50 ohm impedance matched to the board's characteristics. I eliminated the GND ...
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268 views

Can I use meander antenna as show in below pic

I wondering will above antenna work properly or not because most of the PCB design layout antenna directed in right side & feed length remain unchanged. As per as I know, feed length does not ...
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606 views

Power supply of board based on tp4056 with protection gives too low voltage

I have a project on small pocket board with a Li-Ion battery so I made a pcb with power section based on a tp4056 board (with protection), with LP2985IM5X-3.3 stabilizer. TP4056 charges the Li-ion and ...
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319 views

I2C lines coupled?

I am using a 5k pullup resistor on my SDA and SCL lines. I am using a 62kHz clock signal on SCL. I have made two boards so far. For the first board I routed all the traces myself, but for the second I ...
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406 views

PCB Return Current Path Question

I understand that the return current will use the closest plane to the signal trace. So could you give me answers on these 2 specific conditions. 1)When we have lets say 4 layers where layer 1 2 3 ...
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152 views

PCB layout help for MEMS oscillators and clock drivers

I have this SIT8009 MEMS oscillator at 125MHz frequency (also the same with an OSC52 from SiWard at 25MHz) followed by a 1-to-4 clock driver to distrubute the clock to multiple ICs. When layouting, I ...
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707 views

Micro-USB connector in middle of PCB?

I have a unique situation where I may want to place a Micro-USB connector on a PCB, but not on the board edge. Mechanically, it would make sense if I could place it towards the middle of the board. ...
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570 views

EM interference with hall effect sensor

When using a hall effect sensor like this one, naturally, it will be pretty close to a rapidly changing magnetic field. This means that the analog signal line coming out of the sensor will also be ...
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335 views

Switching problems in class D amplifier

I'm building a class D amplifier with a dsPIC as PWM modulator. The part of the schematic that I want to talk about is the interaction between the microcontroller output (pwm signal) and the gate of ...
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365 views

Problem when debugging ethernet KSZ8081RNB chip on IMX6UL board

I've been working on debugging KSZ8081RNB Ethernet chip for three weeks now and still, I can't find where the problem is. First of all, the board I am working on is including an IMX6UL processor and ...
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529 views

PCB isolation strength VS pad-to-pad distance

Is there any estimation regarding the relation between PCB pad to pad distance and isolation strength? If the board is covered with the mask and the minimum distance is 2,9 mm which isolation voltage ...
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365 views

What is the common cause of short circuit in PCB design

In PCB design there is some clearance and creepage distances to respect according to the UL 60950 standard for example, I want to know why this distances need to be respected in PCB design, what is ...
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478 views

Multiple (independent) circuits on the same PCB in Multisim/Ultiboard

I have designed and simulated a few circuits on Multisim. Usually, I order a PCB for the layout of each circuit independently. However, it is cost-effective to put multiple circuits on the same board (...
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347 views

over-heating with AMS1117-1225L

When connected an external voltage to vout of this 5v regulator, the chip get very hot. I connected a 4v to its Vout, and it draws 500ma. The protection diode from vout to vin doesn't help. My doubt ...
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954 views

Switching power supply layout review

In a previous question where a SMPS based on an LM5118 was presented, some aspects of the layout were pointed out as being problematic. I've taken another look at the layout of that section of the ...
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767 views

PCB Ground and Power Plane Design Guidelines

I am converting a design from through hole components to SMT components. The schematic is identical, except the maximum allowable current through an onboard relay will be halved from 20A to 10A. ...
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156 views

Cooling the IC on a board printed by hand

I'm building a battery charger circuit with BQ24278. The battery draws 500mA minimum and 2.5A maximum current; therefore, I must prevent IC from overheating. I printed the board onto single sided ...
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364 views

Improving PCB layout for regulator circuit

I've made a layout around an Allegro A4490 triple buck regulator, with four optimization goals: minimize loop area/change in area when switching keep the ground attachment of the input and output ...
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414 views

funny shaped footprint pads & PCB123

I am using PCB123 to do a PCB layout and I have a part with some oddly shaped pads specified in the part's recommended footprint. It seems that in the footprint editor, there are only 3 options for ...
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110 views

KiCad - what does this syntax Highlighitng mean, why can't connections be made?

Everything turns yellow and it won't let me make ANY connections in Pcbnew. Does anyone know why this is? Also, when I import the netlist, there are no rat's nest! This is the diagram, but I was ...
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871 views

Ground loops on single trace in the middle of a ground plane

I'm trying to optimize the layout of a MAX1979 TEC driver on a double sided PCB. Is the placement of single, small traces in the middle of a ground place, as seen below on the bottom side of the ...
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497 views

How to create a footprint with a pad on the component side in gEDA pcb

I've read a bunch of tutorials, but can't figure out how to do this. What I want is a pin where the pad is on the component side instead of the solder side and the hole is plated so that it can be ...
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170 views

Ground plane and magnets

I am making a wheel encoder out of a Hall Effect sensor with magnets in a concentric circle on the wheel. The Hall effect sensor is on a 2-layer 9x5mm pcb. I usually fill in the layers by drawing a ...
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222 views

Optimizing geometric dimensions of the stripline in AWR DE (Microwave Office) or similar software

I'm designing a stripline step inductance to compensate the capacitive impedance. My goal is to minify the WSVR parameter of the port and I may vary the dimensions of the stripline (widths and length) ...
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2answers
37 views

Altium - Linking Sheet Entries/Ports with Net Labels

I am struggling to find a way to get the compiler in Altium to see a Sheet Entry/Port (tried with both) and a net label on the same sheet to link. This redacted schematic page shows what I have (this ...
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19 views

eagle library model for STM32F730R8T6

I'm designing small DSP device, currently I've been using stm32 development board but now I need to move to dedicated PCB. I can make footprint for uC myself, but I believe it should be available ...
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35 views

Proteus PCB layout components problem

I am designing the PCB layout but some number of components forming the group. I can't able to use this component. I am not able to pick a single component. I have attached the problem image below. ...
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34 views

How to make polygons smoother

I am designing a board using Altium Design 18.1 and I have just poured this GND polygon and it looks so roughly is there any way to make it smoother?