Questions tagged [trace]

Lanes of copper on a printed circuit board, for carrying current or signals between pads

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2answers
459 views

Differential impedance calculation: reference plane doubt

I'm calculating the width and spacing for my differential signals to meet impedance requirements. I have downloaded Saturn Impedance Calculator for making calculations. My pcb stackup has embedded ...
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1answer
40 views

Compromising on placement or routing of decoupling cap with BGA package

As far I know there are two important points related to power-supply decoupling capacitors. First the placement be less than 3 cm from the digital IC. Second the power tracks route pass through this ...
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1answer
61 views

Is it bad practice to have power lines on a PCB instead of a plane [closed]

I am designing a PCB and am wondering what the downsides are to having a 5V trace instead of a plane.
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1answer
96 views

PCB Design - How much length can I2C lines differ by?

I am designing a PCB that uses I2C communication and was wondering how much length the SCL and SDA lines can differ by. EDIT: Clock frequency can be anything from 95kHz to 400kHz. Is there a ...
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0answers
394 views

Can a dental X-Ray machine be used to look at PCB

I have an old castaway PCB board that was being thrown out, but I am having a hard time figuring out where all the traces go. Could a dental x-ray device be used to scan it (thus making it easier to ...
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1answer
40 views

Why do PCI Express riser/adapter cards have electrical components?

I'm looking to make a custom PCI Express right angle adapter because the ones on the market don't work with my space constraints. Now, because it's basically an extension cable, I'd imagine it should ...
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2answers
38 views

Allowing redundant tracks in EagleCAD

I have a 2-layer PCB, where I'd like to connect the top and bottom layers of two pads with a trace. However, when I try to connect one layer, the other layer simply disappears, as shown below, where I'...
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2answers
720 views

PCB Trace Repair (Need to keep track shape?)

Need to repair a trace on my PCB. The burnt trace has a hairpin turn on it. Instead of following the same hairpin shape, can I just bridge across the undamaged points at the bottom? And also, the ...
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3answers
460 views

STM32 (SWD) printf not working

I'm new using STM32 microcontrollers, I have been trying to use the printf tracing in my code without success, anything is printed on the console. I can start a debug session, I can place breakpoints ...
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6answers
4k views

Breakaway PCB Design

I am aiming for a breakaway PCB design for a small series where an unneeded compartment can be broken off. (See Image below) I saw this for example on the STM32 Nucleo boards, where it is used to ...
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4answers
5k views

Meandering traces necessary for 24-Bit parallel RGB LCD interface?

I am working on a project that interfaces an Atmel SAMA5D3 MCU with a LCD TFT display. The interface between both is 24-Bit parallel RGB with HSYNC and VSYNC signals. The resolution of the display is ...
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1answer
49 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 ...
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1answer
41 views

Separation of same layer traces

I've seen this capacitor: https://api.kemet.com/component-edge/download/datasheet/C0603C221JDGACAUTO.pdf It is a 0603 capacitor with a 1000VDC rating. As I am familiar with IPC2221, this did not ...
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1answer
77 views

How can I determine the best trace width for my pcb?

In my project I use 2 external layers in air. How ever in my circuit the maximal current (Imax) in transient mode is about 70A and in steady sate it gets to 12A. My question is, how can I know for ...
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1answer
62 views

Altium Trace, Silkscreen not solid ie only showing outline

Whilst working with Room Copy key command (D-M-C) I have inadvertently changed something which has resulted in my traces and overlays showing as their outline only. Does anyone know what I've done to ...
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0answers
46 views

Different trace width signal transmission line

I have a really basic question. I am wondering what happens physically with the signal, if I have a change in a trace width (see picture below). My point of view is that you have a reflection of the ...
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1answer
97 views

Traces over ground plane [duplicate]

Sometimes it cannot be avoided to run traces over a ground plane (bottom layer) in a two layer PCB. I have two questions regarding this: In the (simplified) example below, what is preferred? To use ...
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1answer
59 views

Vias or traces through two pins of e.g. resistors on a PCB?

I made the design below in KiCad. It's for me a test to see if I can solder SOT23, 0604, 0805 and 1205 components. Someone said it is not a good idea to make traces between two pins of a component (...
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0answers
35 views

Learning designing a Arduino pcb, doubt about USB traces

what consideration should I have for the USB section. How do correctly the usb traces? What means this curves? This is my reference schematic and due board. Thanks
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0answers
21 views

CAN Bus Isolated Ground Trace Layout

I'm using an ADM3053 isolated CAN transceiver in my design, which, due to layout constraints, is located ~6" away from the board CAN connector. The CAN_H and CAN_L traces are routed as a 100Ohm ...
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1answer
42 views

How critical is it for SN65HVD1780DR A/B Differential signal lines to have matched trace length?

How critical is it for the A/B differential signal lines of SN65HVD1780DR to have matched trace lengths on PCB?
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5answers
638 views

PCB alterations post-production. Or, how do I not stab myself while scraping off the copper?

I made a PCB that I am happy with (it works!). This is for a power circuit, and I have realized (way too late) that I want a switch on the board as well. I bought a switch from a hardware store that ...
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2answers
237 views

Reduce impedance for power traces of a decoupling Cap when ground planes are not directly under

I am using an SHTC3 temp and humid sensor to send readings using I2C lines to the MCU. Based on the datasheet for SHTC3 to make sure the sensor is reading ambient temp without the interference of the ...
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3answers
244 views

Surge Current on PCB

When designing a PCB, do you need to worry about the inrush/surge current or just the continuous/RMS current on the board? Everything I have seen including IPC documentation is for continuous current....
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4answers
594 views

Beyond what is recommended by fabricators, how far should traces be from SMD pads?

Having followed a fabricator's DRC (this case being OSHPark), this distance between an SMD pad and a trace is considered acceptable (see attached images). However, I wanted to inquire about what the ...
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1answer
512 views

Routing large RF trace to small SMD pad

I am designing an RF board in Altium where due to the dielectric selected and its thickness, the trace width for a 50 ohm characteristic impedance is thicker than some of the SMD component pads. What ...
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2answers
1k views

LM13700 Question

I'm currently troubleshooting a state-variable filter I built. All of the filter types work, but the resonance pot has no effect. Tracing a sine signal through the feedback pathway, I found that it ...
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4answers
2k views

What is the name of a footprint that is designed to let you cut the trace between two nets?

I am designing a board where I want to have the ability to separate the connection between two power net's by cutting a trace. Originally headers were meant to be used but due to size constrains I ...
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2answers
3k views

adjacent trace capacitance (horizontal)

I find a lot of online tools to calculate the capacitance between two traces (or a trace and a plane) on opposite pcb layers. One such tool can be found here: http://chemandy.com/calculators/...
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2answers
220 views

Why sometimes some PCB designer add extra traces to connect two pin to each other?

I've checked a PCB board which has designed by very famous company and I saw something weird.They connected two pin to each other 2 times and from the top and the bottom of the board I am going to ...
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2answers
113 views

Replacing burnt traces

I have a tiny PCB that I've been working on and off of for a while now. I received it with leaking batteries, and it had corroded some of the traces off the board. Most recently, I tried redrawing the ...
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2answers
465 views

Routing thick high current traces to small SMD pads?

What is the best practice for routing high current traces through the pads of small 0603 components? I have a wide high current trace which that passes through a 0603 decoupling capacitor. Initially ...
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3answers
12k views

How far can mains voltage arc in air?

I wondered this while soldering a mains voltage circuit board and was surprised by how close together the traces were. It has obvious implications in design of electrical plugs, and the proximity of ...
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3answers
657 views

Minimum PCB Trace width with SMD components and Autorouter problem

I would like to receive some suggestions from you about the trace width for my PCB. I'm using some SMD components (ATmega328p TQFP32 and FT232), the main power is 5VDC at maximum 2A. I use also a ESP ...
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0answers
38 views

Analogue Video Trace Matching

I'm working on an analogue audio, video and sync board for my Dreamcast. Something I've been wondering about is the tolerance for analogue video, specifically RGB, in regards to the delta for trace ...
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3answers
191 views

How to fix incorrect routing to SMD transistor terminals

I've got a doozy of a situation: On this circuit I had made, I routed an IRL530N D2Pak transistor with Source and Gate switched....the large heat pad should be the gate input, but instead I routed it ...
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0answers
48 views

Antenna trace 135 degree bending

I designing PCB for SIM7600CE with space constraint.Here, I placing filter matching and the antenna section through 135 degree angle traces (GREEN MARKING).Is it Okay?Can I have any PCB guidelines? ...
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6answers
5k views

Is it OK to route a trace through a pad?

Will I have any trouble routing the traces in this way? (VCC and GND) Is it OK considering that the entire circuit current is under 50mA?
2
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1answer
115 views

DDR Trace Length Inside Package from Simulation Model

The DDR4 in question is a Micron MT40A512M16JY. From the vendor site, you can get the datasheets, specs, sim models. I assume from the sim models you should be able to see the trace length of each ...
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1answer
164 views

DDR3 trace length: need a confirmation

I am reading JEDEC DDR3 specification, and so many other documents on DDR3 guidelines. Before I move to pcb prototyping, I just need a confirmation. I connected all my lines, respected the grouping, ...
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0answers
37 views

Slewed fpga drive rise time on pcb to enet phy

What can cause rise times to be slewed from an fpga to an enet Phy? Can it be trace capacitance? This is a high density 14 layer board . Traces route from fpga to ribbon connector, along a short ...
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0answers
40 views

Faster 8051 not taking the slower 8051 pin status correctly

I'm trying to do a rather simple data transaction between two 8051 microcontrollers using a variant of the SPI protocol. The large one is a slave and the small one is a master. The documentation for ...
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4answers
61k views

How to make traces on an universal PCB?

I hope this question won't be closed as too subjective. I'd like to know best practice - how to make traces on universal PCB's with individual holes without traces (like the following image). My idea ...
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1answer
35 views

Antenna CPW internal layer

I see on the internet showing CPW( coplanar waveguide) always placed on TOP layer with ground underneath. This is what I usually do. Is it possible to place a CPW in an internal layer? if so what ...
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4answers
1k views

Is it bad to run traces directly over each other on separate layers?

A bit new to PCB design, I have to run two traces between two pins, and the best way I can think of is to have one trace go to the bottom layer through a via and then run directly under the top layer ...
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0answers
111 views

How far away can DDR3 memory be placed from the SoC?

I thought of an idea where i have a pcb with a soc on it, and a seperate one with the DDR3 memory that can snap into each other. This way i can replace or debug specefic parts of the system and have e....
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1answer
92 views

How to set the width of all the traces together to the desired value before using autoroute option in Autodesk Eagle?

How to set the width of all the traces together to the desired value before using autoroute option in Autodesk Eagle? every time I use autoroute, the trace width is by default set to 0.0154mm. I have ...
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1answer
456 views

Is there available differential impedance calculation for this stripline configuration?

I am trying to calculate the differential impedance of a differential pair in a 4-layer PCB as follows: Layer: Low speed signal Layer: Power plane Layer: Differential pair Layer: Ground plane I am ...
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0answers
73 views

Oscilloscope Trace Appear Delayed

I saw a thing on my GDS-1052-U oscilloscope: if I set the time base to 25mS/div there appear a delay of the signal on the screen. So, when I rotate the knob for the time base to 25mS/div, there is a ...
3
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1answer
311 views

How can I account for package trace length in KiCAD?

The documentation I got for the MCU provides "package trace length" (in micrometers) as well as "package trace delay" (in picoseconds). For example like this - 6535.15 um package trace length for M_DQ[...