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.

learn more… | top users | synonyms

5
votes
2answers
152 views

PCB's and designing power connections

I've designed a few PCB's now, but never put much thought into good practices. They were small boards and most of the emphasis was put into just making sure everything that needed to be connected was ...
1
vote
1answer
19 views

Make a pad connect to two nets with different names in Eagle

I have a part that is an SMT 'jumper', it is unpopulated and you use it by bridging the pads with solder. I want to put a track from the pin pad to GND. But the pad pin needs to also go to an address ...
2
votes
1answer
24 views

Cutout a polygon from another in any layer in Eagle CAD part creation

I am trying to create a part with a bespoke pad. How do I cut one polygon (for where the hole will be) from the original pad polygon. I don't just want to make a dimension layer and let the PCB house ...
0
votes
1answer
20 views

Eagle Clearance Error on DS2784

I am using the CAD drawing for the DS2777 from Maxim Integrated. ...
9
votes
2answers
693 views

How to route with minimum noise

I'm facing a dilemma on how to route correctly in order to minimize noise on a data signal line. In the example bellow there is a 2-layer flexible PCB (which is very thin). The copper layer is 1OZ and ...
2
votes
1answer
39 views

CadSoft Eagle polygon won't reach pads in Molex library

I'm using the Molex 5569 library in CadSoft Eagle. When I create a polygon, it won't reach the pads at all. The problem occurs only with components from this library. Have a look at this screenshot ...
1
vote
2answers
142 views

Complexity involved in building a single board computer [closed]

Our high school has tasked my and a friend of mine with with building a web connected controller for a hydroponics system. The school has budgeted 5k for us to spend as we like, and we are intent on ...
5
votes
4answers
414 views

How should I connect AGND and DGND

I have been reading about grounding in a mixed signal systems. Do I get it correct that it is best to group analog and digital elements and then have a single ground plane, as long as the digital ...
0
votes
2answers
71 views

Schematic Design and Non-PCB Mounted Components

I am working on a bipolar power supply for hobby and educational purposes. Concerning the schematic, is it possible/good practice to place devices that don't go on the PCB in the schematic? ...
0
votes
1answer
29 views

Hide particular airwires/nets in eagle

Is it possible to hide particular airwires in eagle, without hiding all of them? So if there's a net I am not currently interested in, but it has a lot of connections, confusing where other airwires ...
10
votes
4answers
782 views

Reason of multiple GND and VCC on an IC

What is the reason that most of ICs (e.g. MCU) has multiple (A/D)GND and (A)VCC pins? If it is to increase performance of an IC, how does it help to performance? or is it easier for the IC designer ...
0
votes
1answer
38 views

wire bends in eagle

I am trying to do my first pcb design, using the freeware version of eagle 6.5. I will be making a single layer board using toner transfer. I did the routing of all the tracks, but didnt know better ...
1
vote
1answer
82 views

What style screw terminal is this?

we have found a design of screw terminal that we really like but we are having lots of problems trying to source this specific part, I was hoping somebody here may recognize the design and know where ...
6
votes
4answers
700 views

Schematics vs PCB designs

I've heard the terms schematics and PCB designs used interchangeably as well as used distinctively. Are these one in the same, or do they represent to different sets of blueprints? If the latter, what ...
1
vote
0answers
53 views

Is there a Raspberry Pi B+ GPIO header footprint for kicad?

I attempted to make my own using the ModEdit utility in kicad but I'm still having issues adjusting it to the grid even though I followed the standard 0.1'' pitch. It still seems to be off. Is there ...
1
vote
1answer
91 views

Spark Core Shield PCB design review

I'm designing a PCB (a shield for Spark Core - microcontroller + wifi board). It is connected to 5 analog sensors (not on board, using 3pin header) and 4 relays (on board). Output(RJ45) and vias on ...
2
votes
4answers
192 views

Trace width and spacing

I'm designing a PCB board (low current, low frequency) mainly consisting of low frequency SPI and analog sensors. Are wider traces better or does it not matter? And which is better, consistent trace ...
4
votes
2answers
296 views

Unconnected Copper Pour or Not?

I'm finishing a small PCB that has too many traces in order to realize a good ground plane. The circuit doesn't need particular layout precautions, so this is not a problem. Since the ground plane ...
1
vote
1answer
91 views

Altium PCB, plated or unplated pads without hole, what is the difference

When I place a pad, there is an option Plated. Here is the picture What is the difference between plated and unplated pad without hole?
1
vote
1answer
86 views

GPS signal strength issue - route layout problem?

In my design I use GPS module u-blox MAX-7, LNA MAX2659 and chip GPS antenna. First prototype design shows good signal strength, in 2 minutes from a cold start I have a fix. Here is the picture of PCB ...
1
vote
2answers
53 views

PCB designing: facing problem in connecting pushbutton

I decided to learned PCB designing using EAGLE 7.1.0. So I first of all I go through this video then through this video. Now I started designing a board for ATmega16 microcontroller. For this I ...
0
votes
2answers
59 views

How to deal with devices connected via a connectors in schematics?

I have a few sensors (potoresistor, temp sensor...) that connect to the board indirectly. The PCB will have a connector such as the molex 4pin fan connector that will in turn connect to the ...
4
votes
3answers
118 views

How to isolate processor noise

I'm designing a board that consists of a dspic33F, responsible for running a noise reduction algorithm and compressing audio with a Speex library, and an audio codec connected to an electret ...
4
votes
2answers
128 views

Do vias introduce more noise to signal

If I have a small signal, does routing it through vias to different layer introduce any significant noise on the signal compared to routing it within same layer without any vias? Considering all other ...
11
votes
4answers
570 views

PCB, pads with holes but with different nets on top and bottom sides

I need pads with holes in by PCB, but the top and bottom side of the pads need to have different nets i.e. the top and bottom sides must be isolated. Here is the picture Is this possible to fabricate ...
8
votes
2answers
1k views

What is the use of the golden like coat on this circuit?

The below PCB belongs to a wireless access point. Could anyone explain what are the golden-like part of the circuit that is indicated by the red circles(ish)? What material is it? What is the the ...
2
votes
1answer
58 views

27512 pinout and PCB layout

I'm trying to design PCB traces for a 27512 EPROM chip. But its pinout for the higher half of the address bus seems completely illogical to me and I cannot imagine how should I lay out my traces for ...
0
votes
2answers
65 views

Custom Eagle Part has isolation built-in?

I've just created the footprint for a QFN-56 8mmX8mm to be used with the TLC5958. It seems like there is some sort of isolation built in to the center pad and I cannot figure it out. In the image ...
1
vote
1answer
30 views

Need some help learning to make my own parts in Eagle

I am extremely new to using Eagle (or creating circuits in general). I've been searching around online for tutorials on making your own parts in eagle. However, I still have a few questions and I was ...
0
votes
1answer
62 views

Books on PCB design [duplicate]

Anybody knows a good book on pcb design? I need to learn some theoretical concepts for designing pcb for usb/ethernet application.
-1
votes
1answer
115 views

Smallest possible PCB size for TI CC3200 [closed]

I'm just getting started with hardware side of Computers. At this point, I'm really interested in TI's CC3200 Network Processor, which has an integrated CPU to allow me to run custom code. You can see ...
2
votes
1answer
63 views

Stripline reference plane discontinuity in reference design

According i.MX6 SMART DEVICE SYSTEM of freescale layout board, it uses 8 layers, my question is about the inner layers, they are striplines with a continuos GND plane in one side but in the other side ...
0
votes
0answers
45 views

KiCad - what does this syntax Highlighitng mean, why can't connections be made?

Everything turns yellow and it won't let me make ANY connections in Pcbnew. Does anyone know why this is? Also, when I import the netlist, there are no rat's nest! This is the diagram, but I was ...
0
votes
0answers
34 views

Choosing a footprint in KiCad?

So, let's say I'm composing a schematic for a circuit I'm designing in KiCad, and... done. I now have to to choose a footprint for my components. How does one ...
2
votes
2answers
110 views

When is it theoretically possible to fit PCB circuit on x Layers (emphasis: x =1)

When is it theoretically possible to fit a given circuit on a certain number of layers? (Presumably PCB layers.) What is/are the name of the mathematics/algorithms that might determine this, or ...
4
votes
2answers
142 views

Creating printed circuit boards (PCBs) which aren't flat

I would like to create a printed circuit board (PCB) which is not flat and which is not shaped into a square, but don't know how to proceed. Can Cadsoft Eagle create such a board? If so, how? What ...
4
votes
1answer
64 views

Bypass capacitors between via and chip?

In Decoupling caps, PCB layout, three variants of placing bypass caps are presented: In the comments, it is mentioned that C19 is the worst approach, C18 slightly better and C13 the best way, which ...
3
votes
1answer
119 views

Testing procedure for a PCB

I have a little bit of experience with PCB design and made a couple of small circuits for learning purposes. I need to test out a new PCB designed by another person and its kind of a complicated ...
3
votes
1answer
81 views

Ground and power PCB layout for MCU

As you know most of the MCU's has several Vdd and Vss pins. In the case of two-layer PCB it seems convenient to use some polygons beneath MCU (like on the figure below). The first option is treat the ...
0
votes
1answer
72 views

PCB Trace Orientations [duplicate]

When inspecting a PCB earlier today it occurred to me that all traces you find on modern PCB's are confined to 45 degree increments with respect to the (typically square) board edges. What is the ...
6
votes
8answers
597 views

How do you cover up exposed high voltage pcb traces?

This is my PCB: The thick lines should be able to pass a high voltage (230VAC) signal through it. The board will be kept inside a enclosed box. In my case, the signal on the board is only one ...
-2
votes
1answer
61 views

Exporting from Altium to CST PCB Studio

Based on CST website, they claim that CST PCB Studio can import Altium files. But when I open Import on CST , it gives me just these options : I tried to Export Altium to HyperLynx and Import it ...
2
votes
1answer
64 views

Altium polygon pour doesn't cover same net pads

I've made boards and seen more that use polygon pours that flow over pads that connect to the same net. However, I was tasked with making minor changes to an old board that I didn't design. On the ...
0
votes
2answers
115 views

How to create rectangular holes in ARES?

I bought this three phase rectifier from local store and it has rectangular connectors, Now I need to make its package on the ARES, but I cant figure out how to create rectangular holes in the ...
1
vote
0answers
52 views

Ground loops on single trace in the middle of a ground plane

I'm trying to optimize the layout of a MAX1979 TEC driver on a double sided PCB. Is the placement of single, small traces in the middle of a ground place, as seen below on the bottom side of the ...
3
votes
1answer
211 views

PCB design: the setting of the test point and the use of variable resistor

I am designing a PCB circuit and meeting two problems: My design includes a two-stage MFB band pass filter. To make sure the center frequency of the filters is the same, I need to add a variable ...
1
vote
1answer
63 views

Arduino Ground reference plane

There are three GND pins on the Arduino UNO pinout. As I'm trying to design a mixed signal PCB to act as an Arduino Shield, I wonder how I should connect those pins, i.e. to the analog or digital ...
2
votes
2answers
86 views

How does Altium Designer's “impedance constraint” feature work?

Altium has a design rules option for setting a track width constraint according to line's impedance (e.g.; 50\$\Omega\$). How do I use it? Please give me instructions or a link to an online tutorial. ...
4
votes
3answers
187 views

Solder blobs on PCB traces and vias

On several PC motherboards, I've noticed some solder blobs on traces and vias. What's the deal with that? Are they some kind of test points? If so, how are they used?
0
votes
1answer
72 views

Trace aligment in a double sided PCB

Are there any layout requirements/special considerations when routing traces on top and bottom layers of a double sided PCB, e.g. angle between traces, can traces pass beneath an IC, etc? I know that ...