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.
2
votes
2answers
93 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 ...
6
votes
2answers
114 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 ...
5
votes
2answers
93 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, ...
2
votes
0answers
29 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
39 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 ...
2
votes
2answers
99 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
104 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
39 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 ...
11
votes
2answers
159 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 ...
3
votes
2answers
95 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, ...
8
votes
2answers
233 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
42 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 ...
-2
votes
4answers
160 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 ...
5
votes
3answers
168 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
1answer
52 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 ...
