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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Eagle mixed manual and autorouting approach [duplicate]

Often in Eagle I find myself routing important bits by hand manually, and then letting autoroute finish. If I want to redo the autoroute, maybe with a tweaked DRC or something, it would be convenient ...
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1answer
152 views

How can I design my PCB in a way I can debug the Atmel microcontroller on board?

We are designing a board around Atmel SAM4E microcontroller, and use Atmel-ICE for debugging/programming. To save space, we would like to avoid including the whole ICE connector. Which are the minimum ...
2
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1answer
60 views

What to consider when designing a pcb for HV?

The question is already in the title: What should I consider when I want to design a PCB with a voltage output up to 2 kV? Only the output lanes are going to be on this level, the other lanes are on ...
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1answer
37 views

Eagle Auto Router Display

I've been having difficulty finishing the routing on a PCB I've designed. This is the first time this has happened really. I have miles of free space, yet it only gets to 96.4%. Anyways, I can't find ...
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1answer
87 views

LTC3355 backup DC/DC regulator output voltage sags under load in boost mode

Background For a hobby project I have designed a board using the LTC3355 DC/DC regulator to work as a power supply. I am a software engineer by trade, and I am thus totally underequipped to properly ...
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1answer
48 views

Can I cross the output inductor trace with input power line?

I'm attempting to learn a little more about SMPS design while referring to existing designs and posts such as this one: SMPS PCB Design Critic I'm implementing an AL8805 based constant current buck ...
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30 views

Design of Capacitive electrodes using Kicad

I am looking into building a capacitive electrode. I find a lot of research papers available online , however none that tell me how to actually construct the capacitive electrode. Most deal with ...
2
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1answer
29 views

Eagle tStop pad colliding with other pads

As you can see from the image, the tStop layer is colliding/wildly close with other tStop pad layer. Is that a cause of concern? IC is Linear Technology battery management IC - LTC4155. Package is ...
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1answer
55 views

Original motherboard component + redesigned PCB = Well working? [closed]

Well I bought my laptop about 3 years ago, and I want to replace motherboard. I have a nice Micro-ATX board, but as I know, this desktop motherboard cannot fit in laptop. So I'm planning to figure ...
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1answer
28 views

Designing a Power signal plane to draw heat from a PoE Module

I am designing a PCB that would be powered by this PoE Module. The PoE module provides 5V output and drives a microcontroller, ethernet interface controller and other lower power circuitry. I do not ...
3
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1answer
99 views

PCB data trace lengths tolerable difference for high frequency

I have to interface a camera to a controller using the DCMI protocol for my project. I have around 17 (data+control) lines which are used with the camera. The frequency of operation is about 10 MHz. ...
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1answer
49 views

Altium Error: Multiple top level documents has been used

I made a project with two PCB boards. There are two top level sheets, and two corresponding PCB boards for each. The Power supply board is only providing power to board A. I have been getting ...
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4answers
173 views

How to implement 8-bit 2:1 multiplexers on a PCB?

I need to implement a 2:1 multiplexer for 8-bit data. That is: as inputs it should take two 8-bit numbers and a Select line; and as output an 8-bit number. I could use two 74HC(T)157s (this is a quad ...
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1answer
44 views

PCB footprint recommendations for FPC soldering

I'm considering making a PCB to which I would directly solder an OLED display like this; it has a 30-pin, 0.7 mm-pitch FPC connector (a link to the datasheet is on the page). What's the right way to ...
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1answer
85 views

Twisted pair coil embedded on a PCB

Has anyone tried twisting very thin wires(of order 100 microns) and then sandwiching it in between 2 layers of a multilayer PCB? I have a problem of EMI and looks like twisted pair is the only ...
4
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1answer
361 views

Why don't I need to consider trace width for a high speed oscillator crystals?

I have followed some reference designs that uses crystals like 40 MHz for the MCU, and I have not considered the trace width to do impedance matching. The result is that the boards works fine (I kept ...
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3answers
382 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
146 views

Designing PCB for fast data

I'm trying to connect multiple components (same components) to an FPGA output. The FPGA runs at 30Mhz and transmitting both a clock and data on lines connected to these similar components. Each ...
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3answers
84 views

How to measure the bonding wire inductance in lab by myself?

Very curious about the IC design. Everytime when we get our chips , we always need to bond wire the chip to connect the PCB. Even though the factory always claims that the bonding wire is 0.8nH/mm for ...
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3answers
60 views

Designing a Single Board linux computer [closed]

I'd like to design a single board Linux computer, maybe something ARM-based but I really don't know that much about the hardware side of computers. Does anyone know where I could get some information ...
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0answers
20 views

How to set default fan-out for SOIC/QUAD and BGA in PADS ROUTER?

I have to create a component with SOP family but when doing the fan-out in PADS ROUTER, the Component Properties always set default fan-out for BGA family. SOIC/QUAD is what I want to be. Can anyone ...
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1answer
19 views

Isolation spacing in CPW-G

Is there any thumb of rules how to determine optimum spacing (marked with S below) for a RF signal (@2.45 GHz) on Coplanar Waveguide with ground (CPW-G)?
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2answers
107 views

Why do serpentine traces (supposedly) entail decreased ESD immunity?

In an Intel guideline for their 82579 Gigabit Ethernet controller I've read (p. 18) that a side effect of using serpentine traces on the MDI (which carries the actual Ethernet signals) leads to ...
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1answer
53 views

Running 6 LEDs off 3s (12.6v) and 4s (16.2v) battery

This may be a very simple question but I want to run 6 LEDs on a PCB and I know I can run them simply off a 12.6v 3s battery but if I want to run a 4s battery 16.2 then I will need some sort of ...
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2answers
57 views

Using a DC Power Analyser properly

In the context of an academic project, I designed a PCB which includes an MCU (EFM32), a GSM module and a GPS module. One of the main target was for the system to be low power. However, now that it is ...
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2answers
44 views

Basic 12v LC Filter for Video noise reduction

I'm very new to electronics and I want to build a basic LC Filter with a 12v regulator and below is my basic schematic. Now i'm sure its incorrect but I want to know why and what i'm missing so I can ...
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41 views

Soldering Pad Sizes for Multi-Rotor

I'm new to electronics and have been doing a lot of reading but I am stuck. I'm trying to create a simple power distribution board design for a multi-rotor and I wanted to know what type of soldering ...
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2answers
80 views

What are the plated holes on this PCB for?

In the top left corner of this snapshot, you can see a bonafide test point, TP12. Slightly down and to the right of TP12 you can see an exposed copper pad, also likely a test point. What I am ...
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1answer
49 views

Hole diameters in PCB software - finished or tool size?

Should I specify the diameter of holes on my PCB as before plating (tool size) or after plating (finished)? Michael Leonard says finished Olimex says tool sizes Pcbex says finished ... Thank you ...
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1answer
68 views

Copper weight/thickness current capacity

i have been reading about how Copper weight/thickness is important in several areas of PCB design. The thickness and width of a trace determines the amount of current (amps) the trace can carry. The ...
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4answers
327 views

PCB Tinning to increase current

How can I design a PCB in order for it to have this kind of PCB Tinning finish? I do know this decreases the resistance of the tracks and increases the amount of current it can handle however Do I ...
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2answers
425 views

Gold coated pads

Is there any difference between a gold coated pad and a gold pad? I have been ordering boards from OSH park, they are really good quality, I'm just wondering what benefits this has over silver or bare ...
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4answers
203 views

PCB Layout, Functional vs Actual Pin Order

I'd like to continue this conversation here: CAD Schematic pin arrangement approach Basically, there are 2 major ways to do schematic symbols, either with true pin order or by grouping pins by their ...
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2answers
149 views

Enabling extra routing layers in Eagle (paid version) PCB design

I started a PCB design in the freeware version of Eagle, now I have the full version, but it won't let me route tracks to the extra route layers (i.e: only top and bottom). Starting a new design in ...
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2answers
92 views

How to measure the PCB size?

Can somebody share me your methods measuring the PCB size in CAM Software ? In PCB house ,we always measure the size according to the centre of outline and get the final size of the unit board or ...
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0answers
47 views

How to use vias in Proteus ARES?

Thanks for reading this. I am building a 2 layer PCB. My question is quite basic. I just don't know how to use a via in Proteus ARES. I can place a via down, but then I cannot route tracks to it. ...
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0answers
40 views

Issues in thermal on PCB

i design one power supply board in that some coils are placed on the surface of PCB, that means in center surface of PCB. these coils are dissipating more than 7W on PCB. because of this PCB is ...
4
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1answer
137 views

Impedance matching with only capacitors?

I need to do impedance matching for 33 + j32 ohm source and 16.5 + j0 ohm load. The copper traces adds 99 ohm impedance and 20 degree electrical length. According to smith Chart below, I need to use ...
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1answer
36 views

How to determine dielectric constant and loss tanget of a PCB board at a specific frequency?

I need to know dielectric constant (relative permittivity) and Tan loss of a FR4 board at 2.45 GHz. The specification of the manufacturer is as it is below: Dielectric Constant: Test method ...
0
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1answer
52 views

Single regulator to power mixed signal PCB?

I have a codec (ADC & DAC) with both analog and digital power and ground connections (upper half is analog, lower half is digital). By placing the device package in such a way that all digital ...
4
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1answer
48 views

How to minimize characteristic impedance mismatches caused by vias?

This question springs from an answer here. When using stripline configurations for rf signalling, the conductors are routed on an inner layer of the pcb, sandwiched between two ground planes. I ...
2
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2answers
59 views

Which of these Stripline Impedance Calculations is correct?

Different sources are giving me drastically different characteristic impedance values, and am hoping someone will verify them for me. Generally, with microstrip, I start with an online calculator to ...
3
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1answer
181 views

Unable to delete Trace in Eagle

After running the design through the Errors Tool and moving a route that had insufficient clearance, I'm left with this blue segment that is overlaying the red route. Why is it there and how can it ...
5
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1answer
108 views

Requirements tools for PCB design?

I'm writing requirements for our PCB designs, determining what clients want and what's possible to build. When requirements are finalized, I write tests for the same designs. Right now, I'm doing it ...
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2answers
131 views

Pad hole size for 0.1" Male Headers

I created an Eagle part that has several holes to solder 0.1" pitched break away male headers to, such as the one below. However the pad has a hole thats too narrow for the header! What drill size ...
6
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1answer
74 views

Preferred balun location? (Are differential microstrips preferrable to single-ended?)

I'm designing a PCB with a transceiver that has differential signal pins for rf. These differential signals travel to a balun, which transforms them into a single-ended signal (50-Ohm ...
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1answer
101 views

How to create footprint from IC diagram when no recommended layout is given?

I'm a student trying to create a library part in Altium for an Analog Devices AD8232. Most IC datasheets give a recommended footprint to use, but the AD8232 datasheet only shows the IC itself: I ...
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3answers
979 views

Cleaning PCBS… using water?

I found this video where a technician with a lot of experience seems to clean his PCBs using water, and then he just puts it in the sun so it can dry. I was just amazed to see the circuit keeps ...
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3answers
251 views

Can differential USB traces be routed relative to Power (not Ground) planes?

I would like to route my USB 2.0 (12MHz) signal on the bottom layer of a 4-layer PCB. However, the edge-coupled microstrips would then be referenced to the power plane, not the ground plane. The ...
3
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1answer
81 views

Dual smart battery design and PCB layout

I have a system that is powered by a 7.4V Lithium-Ion battery. The system, which is a combination of processor module and sensors, draws a varying amount of current at varying voltages (5V, 12V, -12V, ...