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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1answer
186 views

building thin devices, how to get started? [closed]

I want to build thin devices, just as thin as those ipod touches, how do I get started? What courses, what machines, what books?
16
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4answers
2k views

What is the best way to short adjacent SMD pads?

Which of the three ways shown above would be the best way to short two adjacent SMD pads together, and why? These are TSSOP pads and the assembly process will be lead-free reflow, if that matters. ...
4
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1answer
3k views

Are small valued capacitors effective in the device power input?

I am really confused with all of the ground bounce, decoupling, bypassing, filtering, resonance and ESR&ESL stuff. What I currently understand is: Ground bounce occurs when the (capacitive part ...
2
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2answers
2k views

How to check the PCB design for manufacturing(DFM) [closed]

I am interest in PCB design. As to design for manufacturing, can somebody share some guidelines or links to learn? Can the PB fab house be help with this job?
5
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2answers
423 views

Adequate decoupling / noise reduction for two accelerometers?

This is my first PCB, so please forgive some of my ignorance! I'd like to mount two accelerometers (ADXL193: +/- 250g), orthogonally, on the same PCB, and have a question about noise. The current ...
3
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2answers
1k views

Why we need blind or buried vias in our layout ,What is the difference between microvias?

I have a 6 layers board with blind vias from 2-3-4-5 and micro vias (size:.004") While it isn't a high density circuit with conductor width 6 mil and pads.02") Can anybody share some tips on these,Why ...
17
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3answers
4k views

Is connecting two GND planes with vias a standard practice?

I've been studying the Arduino Uno layout and noticed that there are about 40 vias that connect the GND polygons on the top and bottom. Here's a picture with the vias circled: Is this a standard ...
6
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1answer
780 views

How do PCB fabrication houses make PCBs?

I know the different ways of making PCBs at home, but I can't seem to find a lot of information on how board houses professionally make their PCBs. Is this how they do it?: http://www.youtube.com/...
7
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3answers
13k views

Missing components in Eagle Library

I am missing libraries of certain ICs for use in Eagle. Can someone guide me to a source where I can find these IC libraries? I am asking this question to find out if there is any central repository ...
2
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4answers
3k views

What's the Actual Speed in GHz of RapidIO or RocketIO serial interfaces?

When reading about high speed serial interfaces like RapidIO or RocketIO, I find data rates of 3.125 Gigabits/second and more. My question is: 3.125 Gb/s = ?? GHz What's the relation between Data ...
4
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1answer
457 views

RF - changing a trace slightly from original design…?

I am trying to make a new PCB for my self just for experimenting. I found a document on TI website that suggests using a single chip 50Ohm Balun That is fantastic as it saves anybody faffing about ...
2
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3answers
2k views

Breadboard/veroboard and SMT

By now, through-hole components have almost completely disappeared from consumer devices and also professional PCBs. But what is the alternative to build breadboard-veroboard for SMT technology? ...
16
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2answers
1k views

How to transmit high current (2.6A) with low voltage (1.2V) for a long distance?

I want to supply a DSP with 1.2V. This DSP needs 2.6 Amps of current at full load. The minimum supply based on the electrical specs of this DSP is 1.16V, which means that the maximum voltage drop ...
10
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3answers
10k views

Blind/buried vs. through hole vias?

I'm trying to learn PCB design and, from what I've read and seen, there appear to be three different types of vias: Through hole - goes all the way through the board Blind - goes from the top or ...
5
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5answers
7k views

Can a trace connect to a pad on the top layer?

I'm making my first two layer PCB and have am unsure of whether it's ok to connect a trace to a pad on the top layer (if the pad is on the bottom layer, that is). Here's a picture to show what I'm ...
56
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4answers
155k views

What do the PCB markings mean?

On a printed circuit board, I see lots of tiny letters and numbers. Is there some kind of standard that dictates what letter indicates what type of component?
12
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3answers
5k views

Soldering heatsink pad on bottom of IC

I am attempting to make a board for the tlc5951 24-channel led driver to drive an 8x8 rgb led array. I have made what I think is a good eagle library for the sop-38 package, but I am not sure what to ...
7
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3answers
1k views

Want my PCB design to work right the first time!

Just finished a design of a 8-Layer PCB, the highest frequency is 125MHz. I want this design to work right the first time, how should I revise the design and what should I take care of? Something ...
9
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1answer
4k views

Hand-routing PCBs for SMD

I've routed plenty of through-hole boards, but I have no experience with SMD routing techniques, and even the look of the board feels a bit ‘alien’ to me. Any tips for placing/routing prototype PCBs ...
11
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4answers
24k views

Implementing guard trace/ring in PCB design

I have read here and there some articles about pcb guard trace/ring. But none of them discussed how to correctly implent it. What I could find were some pictures and comparison that cant help me at ...
3
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1answer
1k views

High Resistance PCB materials - reasons behind it?

I like to know if there is a relation between using a high resistance (the more expensive stuff) and environment noise effect on circuit. The reason is I heard for high frequency or sensitive ...
2
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2answers
558 views

PCB printer - etcher

I am looking for a machine for PCB fabrication. Can you help me understanding the type of machines available on the market for a hobbyst use?
3
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2answers
5k views

How do I draw a PCB antenna in Eagle without DRC errors?

I'm designing a board that should contain an antenna I found in an application note. I'm using Eagle and I tried to create a library part for the antenna. However, since the antenna is basically a ...
1
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2answers
1k views

Will there be a problem if I stay almost in the border in trace spacing when dealing with line voltages?

The IPC-2221 standard shows that 1.25mm will be enough at less than 3050m at 250V (220V is the line voltage here in Turkey), even if the coating gets damaged. However, people generally recommend 5mm ...
6
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4answers
3k views

Best way to learn Signal Integrity [closed]

I am currently working on ECAD. Just to add more technical values to my work, I want to learn Signal Integrity and Thermal Analysis. What are the books,links you would suggest me to learn it? I am ...
2
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1answer
627 views

FT2232HL interface board critique

This is my first "real" design, a (more or less) universal USB serial interface board with two RS-232 ports, one RS-485 and one CAN interface. Hi-res schematics, top and bottom PCB layers with bottom ...
2
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2answers
1k views

How can I improve this SMPS design?

In: 21-32V Out: 12V, 3A Working Frequency: 300 KHz Controller IC: FP5138 from Feeling Technology MOSFET: IXTP44N100T from IXYS Schottky Diode: MBR20100CT from ON Semi The MOSFET and the diode ...
33
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10answers
24k views

Looking for a good freeware/open source PCB design software equivalent to Altium [closed]

I am familiar with Altium PCB design software in my workplace. But thats an expensive suite to maintain. Is there any decent enough free software which I can use at home for my pet projects? I have ...
2
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4answers
625 views

Homemade printing and soldering for small components.. the best way

Which is the best way to solder small components such as SOIC or QFP44 packaged components to a PCB without using adapters? And how can I manage to print PCBs with small track distances and widths ...
11
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3answers
7k views

Audio Amplifier PCB Design Tips

I am going to design a stereo audio amplifier with TDA2030A. This is going to be an amplifier that is going to be powered from 27.6V DC and 12W per channel. Is there any sources that I can learn PCB ...
2
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2answers
578 views

Thermocouple effect on low voltage/current signals in PCB and connectors

As part of my studies, I am designing a measurement setup for measuring leakage current of SMD capacitors in the ranges up to pico Amps. At the moment I am in research periond and later I will have ...
8
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2answers
2k views

How far is “too far” when routing traces for crystals, and how asymmetrical is “too much”?

I'm routing a breakout board for NXP's LPC23xx microcontroller. This MCU requires two crystals if one is using the RTC. These two crystals connect to the MCU with only 3 pins in between: From this ...
0
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1answer
898 views

Design of basic PCB

I am trying to build an Arduino-controlled blimp and am in need of a very basic PCB. I am trying to learn EagleCAD to create a PCB that does the following: Interfaces with the Arduino Fio: on the Fio,...
2
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3answers
5k views

PCB and trace design for high-speed TTL

I am designing high-speed TTL-based processor. I will be using only fast AC, ACT and LVC series, so switching frequencies will be in 100Mhz range with 1-3ns fronts. I plan to use homemade 2-sided ...
10
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2answers
3k views

Is it normal to have a rats-nest of VCC/GND traces under an IC?

I'm attempting to route a simple board, the first I've done in 15 years since I routed a 12V linear power supply in the equivalent of mspaint. This board consists mainly of an LPC2387, which is an ...
2
votes
1answer
910 views

In a ~3 amp circuit, is it required for all ground trace widths to be the same?

I am designing a PCB for controlling servos. My voltage regulator can provide 3 amps to the servos. My Arduino Uno also draws power from the same line. Using an online calculator, I was able to ...
26
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5answers
11k views

Standard PCB Layout Book

Are there any good references on advanced PCB design/layout/routing? There seems to be a large wealth of circuit design books, books about RF PCB design, and books dealing with high-speed digital ...
2
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1answer
1k views

Criticize SMPS PCB Design

Yes, it is me again with a PCB Design. I am learning a lot thanks to you. This time, the specs are; 10-32 V input 35V 4A output Boost converter The controller IC is LM3478. Schematic & PCB: Q1 ...
10
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4answers
24k views

Changing all via and routing sizes at once (Altium Designer, PCB Design)

I have a completed PCB design drawn by Altium Designer. I want to increase via sizes. But there are too much of them, and changing all of them one by one will be a very long and bothersome work. Is ...
2
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3answers
694 views

Guidelines on branching of a PCI express signal

We have 3 PCIe slots on a board, let's call them A, B and C. On this board, slot A will always be populated with a PCIe device, however, among slots B and C, only one of them will be populated. There ...
1
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4answers
2k views

Feedback on PCB layout for Half-Bridge

This is my first ever PCB layout design. I did this in EAGLE and I'm looking for some feedback. Note that this is my first ever PCB layout so I don't know any "rules of thumb". The circuit is simply a ...
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1answer
2k views

Fritzing unrouted connections with Autoroute

Why does Fritzing's Autoroute leave unrouted connections? Is there any way to tell it to route every connection?
2
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1answer
2k views

SMPS PCB Design Critic 3

Can you critique my design? After finishing my 5v part, I've added the 35V part, too. 10-32V to 5V 1.2A SMPS Buck Regulator, the IC is IFX91041 from Infineon. 10-32V to 35V 4A SMPS Boost Regulator,...
2
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1answer
1k views

SMPS PCB Design Critic 2

Thanks for your patient help, I am learning a lot. This is my (final, I hope) re-designed layout. What do you think? 10-32V to 5V 1.2A SMPS Buck Regulator Design. The IC is IFX91041 from infineon. ...
10
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2answers
3k views

Grounding of ADC grounds

Fast, high resolution ADCs, especially ones that have parallel output, usually have a separate supply pin (DRVDD, (drive vdd) or OVDD (output vdd)) presumably because they don't want to couple noise ...
3
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2answers
1k views

Bypass capacitors for BGA packages

We have designed quite a few FPGA-based boards, and so far, we have used a lot of bypass capacitors. Our rule of thumb was, "as many as we can". In our next design, we would like to reduce the part ...
2
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3answers
6k views

How do I look at all the footprints in a KiCAD library?

In the KiCAD PCBnew layout editor, is there some way to see what a footprint looks like before I place it? Or am I forced to select a footprint that has a plausible-sounding (ASCII text) name, place ...
6
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2answers
805 views

Crosscoupling in SMPS PCB layout

I have been reading this application note from National and I have a question about this phrase: ... traces carrying switching currents/voltages must also be kept away from ’quieter’ traces to ...
29
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3answers
9k views

Should I worry about the risk of tombstoning?

A colleague has (apparently unsuccessfully :-)) tried to convince me of the risk of tombstoning in the following situation: He claims pad 1 for R55 and R59 will lose heat faster during ...
2
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3answers
4k views

Finding right component package in Multisim

I have started using Multisim. I designed a 5V regulator and it works in simulation, now I want to export it to UtilBoard but I can not find the right package or footprint for my component as there ...