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.
1
vote
2answers
37 views
Eagle part for “MiniLED” SMT LED
I'd like to use this LED, but its package is just listed as 'MiniLED' in the datasheet. Is that a standard package, or just a Vishay term?
Is there an equivalent part already in Eagle 6? If not, ...
3
votes
1answer
185 views
Need help with selecting an antenna for PCB
I have designed a pair of circuits which utilize the QAM-TX2-433-ND/QAM-RX2-433-ND transmitter/receiver.
So far everything is hooked up on solderless breadboards, with just a length of wire for ...
12
votes
2answers
948 views
Termination resistors: are they needed?
For a project I'm designing, I'm using an IS42s32800 (TSOP) SDRAM with an LPC1788 (QFP) microcontroller. On the PCB I have 4 layers with a ground plane right below the top signal layer and a VDD plane ...
1
vote
2answers
148 views
Chip antenna mounting considerations
I'm using this chip antenna with a 868MHz radio (RFM12B): http://www.johansontechnology.com/datasheets/antennas/0868AT43A0020.pdf
According to the datasheet's mounting considerations there's a trace ...
3
votes
1answer
107 views
Are these pcb layouts good?
I'm working on an USB audio interface; the board has an analog section, with amplifiers and filters for the input and the output signals, a digital section, with the DAC, ADC, and the microcontroller ...
0
votes
1answer
65 views
How do I lay out a 28 pin DIP socket pattern using GSchem?
How do I lay out a 28 pin DIP socket pin pattern in gSchem?
I imagine that I can lay it out manually but is there some sort of library component I can use?
VERSION: 1.6.1.20100214
1
vote
1answer
203 views
How to export Slots in Altium?
I made my first PCB with slots, and Altium is generation two .txt files...one for the drills, and one for the slots...how do I combine them to send it to the manufacture?
4
votes
1answer
62 views
Surface Mount vs. PTH Components For Production
I'm a hobbyist who has developed a product which uses ~20 PTH components. The device is essentially an Arduino UNO with some extra driver ICs and LEDs. I have had quite a lot of positive feedback on ...
-2
votes
0answers
49 views
pcb assembly already preroute [closed]
i have a problem with altium designer, i search to create a project with only one pcb and one sheet which brings together pcbs already preroute.
I already create several project and now I want to ...
4
votes
2answers
158 views
Why Characteristic Impedance must be “50” ohms?
Where does this number came from?
For single ended it must be 50 ohm and for differential pairs 100 ohm. Why?
For PCB with controlled-impedance these are that common numbers. Outside of the PCB you ...
1
vote
3answers
122 views
Cannot find SMD resistors in Altium
I just moved from Eagle to Altium. I cannot find SMD resistors in Altium libraries. In Eagle, there are almost all general components. In Altium there are only few resistors. Where can I download the ...
3
votes
2answers
122 views
Circuit version of a simple if else program
I have written a simple program that controls two motors (outputs) each with two states ( positive, negative) with an Arduino. The motors states based on the status of four buttons (inputs) (Up, Down, ...
55
votes
7answers
7k views
Best One-Off DIY PCB Creation Technique
I have finally built up a lab to design electronics in. I have quite a few designs I would like to test. I have tried the printer toner/iron technique a few times but have found that I cannot create ...
1
vote
2answers
141 views
What would be the best approach to align a photomask onto a PCB panel?
Issue: Alignment of photomask to reference holes drilled
When making PCB in panel form, the reference holes are usually drilled at 4 corners of panel to allow alignment of photomask to the PCB board. ...
2
votes
1answer
50 views
Eagle configure autorouter to solder components (except vias) only on bottom layer of double sided PCB
In double sided PCBs it is difficult to solder through hole components like IC bases, headers, etc. in the top layer. Normally the Eagle autorouter places the solder pads on both sides. That is, in a ...
5
votes
1answer
154 views
14 Layers Stack-up proposal
Could be this stack-up correct/appropriate for a 14 layer pcb?
The PCB includes a CPLD at 50 MHz and a Gigabit Ethernet transceiver at 125 MHz. Both mounted in Primary Component Side.
There are 4 ...
2
votes
2answers
113 views
Need second set of eyes on 555 50% duty cycle soldered protoboard
I'm a hobbyist trying to learn the basics of the 555 timer, and am working off of the 50% duty cycle circuit from the National Semiconductor data sheet for the 555 (PDF pg. 10 Fig. 14) and have ...
7
votes
2answers
135 views
Is it worth going to so much trouble with Ethernet differential tracks?
I am laying out a PCB containing an Ethernet connector with integral magnetics, and a Micrel KSZ8051MNL Phy. This is for a 100mbps application.
In an attempt to reduce EMI, and make the Ethernet data ...
6
votes
2answers
136 views
Mains to low voltage seperation between FR4 PCB layers
I cannot find clear information on running mains and low voltage on adjacent layers on FR4 PCBs. I understand how much creepage distance to allow, but for example, can I run - 50Vdc, 240Vac, 0Vac, ...
7
votes
4answers
264 views
When to change a PCB number and when to change the Revision?
I want to know if there are any guidelines about when it's supposed to change the PCB's number (1.0 or 2.0) or it's revision (Rev A, Rev B).
2
votes
0answers
39 views
Altium: Query to target Vias in Pads
Does anyone have a Altium query/selector that targets vias in SMT pads? I'm routing a very dense HDI board, and would like to make rules that exclusively target vias that are inside a component pad ...
-4
votes
0answers
45 views
learning embedded system [closed]
can someone please assist me regarding :
1 The topics that i should read in electronics in order to learn designing schematics for embedded systems as well PC boards.
2 and reference book that i ...
6
votes
2answers
847 views
Castellated/Edge-plated PCBs: Comments on Mechanical/Electrical contact reliability
(This is a follow-up to this related question).
I'm interested in some feedback from people's design results/experiences with Castellated PCBs as a method of attaching one PCB to another. By ...
6
votes
3answers
1k views
Should I isolate grounds of an isolated DC/DC converter?
If I use an isolated DC/DC converter, when designing the PCB, should I isolate the ground of the input and the ground of the output as shown below?
I've never isolated grounds (except for AGND and ...
4
votes
2answers
106 views
Returning Currents for two side boards and returning current questions
I have some questions these are I am not sure:
I have designed a board that has classical 2 side PCB design. Frequency is not a big issue for me but with ESD my CPU resets itself. (CPU clock 20 Mhz, ...
3
votes
2answers
111 views
Return current in 8 Layer stackup
I have to design a multilayer Board (8 Layer). This is a part of 4 PCBs in a product with plastic enclosure. The high speed signal on PCB are Ethernet, USB2, LAN and UMTS integrated modem. Product ...
-1
votes
1answer
121 views
How to (re)create an USB 3 header interface PCB? [closed]
I would like to start a "small" project. Create an USB 3 version of an existing USB 2 PCB.
On the PCB there is only 2 USB connectors, a capacitor and a USB header (to connect to the USB controller). ...
1
vote
2answers
44 views
Connections of SPST switch-ESE-11SV1
I am using SPST switch as a digital input to my NXP MBED Module.I have done the design of the whole circuit in OrCAD Capture and Allegro PCB Editor.
the switch I am using is Panasonic's ESE-11SV1.The ...
9
votes
6answers
1k views
Finding air wires in Eagle
I am almost done routing a board. However, is telling me that there is still one more wire. I have looked but I just can't seem to find it. Is there a to make Eagle tell me where it is?
11
votes
2answers
172 views
Low volume PCB assembly testing
I've ordered fabrication and assembly of small PCB batches (~100) a couple of times already. Each time, the assembly factory asked me if I wanted to do testing on the boards. Since I'm not a ...
8
votes
2answers
246 views
What is the purpose of the square vias with no solder mask on this board?
This board from an electronic combination lock contains a curious mix of two types of vias:
Small round ones with green solder mask over the top.
Larger square ones without green solder mask over ...
1
vote
1answer
50 views
PCB Board design for H-Bridge TLE5206
I would like to make PCB board for TLE 5206-2G (check the datasheet).
It is TO263 package.
Basically, what i dont know is how to transfer heat out of the IC. I saw few PCB's that has little copper ...
16
votes
5answers
595 views
Board Design for High Impact Environments
I'm looking to design a PCB that can reliably survive constant impact. The board will be rigidly mounted to an enclosure that will protect the board from actually hitting anything. The nature of the ...
-2
votes
4answers
179 views
Software to design a 2-sided PCB with discrete components [duplicate]
I'm quite new to PCB Fabrication. I have a circuit with discrete components on a breadboard. I would like to fabricate this circuit into a 2-sided PCB containing discrete components. Something like ...
4
votes
5answers
934 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 ...
5
votes
3answers
176 views
Electrolytic capacitors connected with one terminal only?
I've got an ordinary PC motherboard. So, out of curiosity, I started looking at the power circuits on it and found several large 1000–1500 μF electrolytic caps:
It's easy to see that their cathodes ...
0
votes
2answers
141 views
Impedance Control PCB design Help
Im new to impedance control PCB design and I got following information from a pcb manufacture.This is their standard stack and I'm planing to control impedance of my design according to their spec.Cos ...
1
vote
1answer
68 views
DipTrace bottom layer pad shape
I'm having a problem in DipTrace. I'm trying to change the shape of the pads on the bottom layer. I have successfully created and had etched a similar PCB in DipTrace yesterday, and have followed the ...
4
votes
1answer
167 views
Heat Sink for SOT223
I am designing PCB a in which I am placing a BSP296 N-channel MOSFET, for switching solenoids:
MOSFET supply voltage is 24V
MOSFET max power dissipation is 1.8W
Max operating temperature is 150°C.
...
2
votes
2answers
172 views
What can I do as a student to be a better candidate for a hardware design job? [closed]
If you were looking to hire a student still in school for an internship position at a high-tech company (say, Microsoft, Apple, or Google) for hardware design. What kind of skills would you be looking ...
7
votes
1answer
219 views
Best place to place a decoupling capacitor
See this image which gives four options to place decoupling capacitors:
(from http://www.learnemc.com/tutorials/Decoupling/decoupling01.html)
I would say option (d) isn't good - I would recommend ...
8
votes
1answer
200 views
Is there a PCB-layout related reasoning behind DDR memory package and footprint?
BGA DDR packages have a unique footprint. There are two columns of pads on both sides of the device, and an empty column in between.
Is there a reasoning behind the placement of these pads (in ...
6
votes
1answer
164 views
How are these pcb pads made?
We want to design a pcb module that should be soldered directly onto customer pcbs (exactly like ICs ect.)
I found a module which does exactly that, please see pdf.
...
1
vote
1answer
84 views
Strange Eagle Copper Pour Issue
I'm experiencing an interesting issue with Eagle's polygon copper pour. As you can
see below, the solid red is the copper pour area, while the dashed line is showing the complete polygon outline (I ...
1
vote
1answer
632 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 ...
-2
votes
2answers
201 views
Where can I order flexible PCBs? [closed]
Question
Where can I order flexible PCBs online?
Does such a service exist form which I can order complete flexible PCBs with components already soldered down? Where?
Background
I'm in the ...
11
votes
2answers
275 views
Techniques for placing components on PCB's
I know that placing components is quite an art rather than following some set of rules to get the job done, but I am looking for some references about the topic.
I already saw this tutorial and it is ...
9
votes
1answer
434 views
A few questions about vias and pads on a PCB
I have been used to work with 1 layer PCB's and prototype boards. On the bottom layer are all the routes and the soldering , on the "top" layer are only the components.
Now, I am trying to work with ...
1
vote
1answer
112 views
Eagle 6 : Problem Importing Custom Parts
Recently started working on a new PCB board for a dev kit. I ran in an issue where I had made a custom part for the M50-3501042 2x10 male header with 0.05'' (1.27mm) pitch.
Note also that this is a ...
4
votes
2answers
138 views
PCB Design Considerations - Copper Pouring
So after a very long effort, I think I've finally come towards the end of my PCB board design. It's a two layer board with no ground or VCC plains (Re-routing is not an option) as I can't go though ...
