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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0
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2answers
52 views

How can I tap into and measure this rf frequency?

I'm new to rf design, although I'm learning rapidly. I've designed a PCB which uses an ultra-wideband (UWB) transceiver. The center frequency is selectable between 3.6GHz and 6.5GHz, with 500MHz ...
3
votes
2answers
279 views

Clock generation on my PCB

I have not a big background in electronics. I am designing a PCB including a MCU (EFM32) and some ICs. I have seen in lots of circuits that they generally add an external Crystal Clock on the board ...
0
votes
1answer
37 views

EAGLE detecting error at Copper Trace intersecting Dimension Outline

The ARDUINO_MEGA part from the Sparkfun Eagle Library is used in my board design. However when performing a DRU check, it seems that there is an error where the top ...
1
vote
0answers
55 views

funny shaped footprint pads & PCB123

I am using PCB123 to do a PCB layout and I have a part with some oddly shaped pads specified in the part's recommended footprint. It seems that in the footprint editor, there are only 3 options for ...
0
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0answers
38 views

Custom USB 7 port hub PCB dasiy-chain

I had a schematic laid out for a custom USB 2.0 7-port hub I needed to create for a project of mine. It currently uses Ethernet RJ45 sockets to provide power and data to each hub (2 Ethernet ports for ...
0
votes
1answer
31 views

Impediance mismatch and amplifier question

I am converting an aviation headset to take a Bluetooth signal. The headset speakers are \$150\Omega\$, and the Bluetooth adapter I think is \$10\Omega\$. The mic will not be used. Can anybody ...
-1
votes
1answer
39 views

What bluetooth chip / type should be used for a remote control car? [closed]

I am building a small remote control car to be controlled by bluetooth (iOS and Android). I am having a custom circuit board built, and I want to know what bluetooth chip I should get. I would like ...
2
votes
2answers
668 views

PCB design review: Decoupling, bypassing and grounding

I'm trying to make my own wireless sensor using ATmega microcontroller. I've some basic understanding of electronics but I'm a total amateur when it comes to designing circuits and PCBs. This is just ...
-1
votes
0answers
33 views

KiCAD footprint of a crystal

I am not sure how to create some not so common footprint in KiCAD. I am using this 40 MHz crystal for my design. The bottom of the crystal looks like this. How can I create those arcs and joints ...
0
votes
2answers
52 views

Testing a board without placing a component

Is there a way to build a (functional) board without placing 1 component? I am designing a PCB and want to have the option to make it work w/ or w/o placing a specific component (X). This component X ...
1
vote
0answers
77 views

Is it OK to place ground plane under transformer?

I have a large transformer (50kHz, ferrite E-core) on the PCB. I want to pass power rails under it on the bottom layer. Should I place a large ground plane on the top layer to shield these power rails ...
0
votes
1answer
51 views

Connecting Terminal Blocks to Second PCB Board

I have a daughterboard with 3.5mm screw terminal blocks (such as Digikey part # 277-5749-ND) that has to be connected to the mainboard, with the daughterboard either parallel or perpendicular to the ...
0
votes
0answers
25 views

KiCAD pin assigment

What would be the best way to connect multiple pins of a module/footprint to a single pin in the schematic in KiCAD? Do I have to edit the module and set the same pin name for the pins I want to ...
0
votes
2answers
77 views

Calculating the Resistor's Power Rating

I'm designing a couple of step-down voltage regulators based on a LM22677 chip (datasheet) and following the example: I want to get 5V and 10V from a 12V supply, but I have concerns regarding the ...
1
vote
1answer
51 views

Orphan polygon not filling

I'm trying to have an area of my PCB with the same geometry on the top and bottom copper layers, but I'm having trouble with the polygon on the top layer. I placed vias on the bottom contacts (which ...
2
votes
0answers
45 views

Is 3dBi PCB etched GSM/GPRS Antenna Possible?

Is it possible to design a GSM/GPRS antenna that has a gain of 3dBi? if not, what is the maximum gain possible with a PCB GSM/GPRS etched antenna? I'm thinking of a PCB sized 11cm long and 5cm width. ...
0
votes
1answer
57 views

Why should PCB design be mirrored before toner transfer?

I am currently designing a PCB to make with the toner transfer method for the first time. I was reading a guide that said to mirror the image before printing it to the paper. However it seems that the ...
0
votes
0answers
46 views

Reverse Engineering Camtastic file to PCB in Altium

I've followed the directions found here but after the step where I extract the netlists, when I export to PCB it gives the following error. ...
1
vote
1answer
60 views

Schottky power diode replacement

I'm trying to implement a 12V to 5V step down voltage regulator with a Texas Instruments LM22677, as suggested in the device datasheet (Pag 12, Fig 20). Regarding the selection of the power diode, TI ...
4
votes
1answer
57 views

ADuM1301 digital isolator - PCB layout question

We are using the ADuM1301 digital isolator in one of our designs. The PCB layout section from the data sheet states: In applications involving high common-mode transients, care should be ...
3
votes
1answer
120 views

Understanding source and return current flow on PCBs

I'm looking for advice and tips related to PCB board layout and signal+ground trace/track routing. I'm designing a 2-layer analog-only PCB that has several I/O signals leading to and from other ...
2
votes
0answers
69 views

Optimal Capacitor Placement on DC/DC Convertor

I'm trying to decide on the best layout for caps on a DC/DC converter. Which of the following options (or another, unlisted option) is the best choice? GND Out plane with 5V Out going the opposite ...
0
votes
1answer
38 views

Headers and Cable for a LCD and UI?

My current layout consists of two 16 pin (8x2) 2.54mm pitch (shrouded) headers. One is for an 16x2 LCD screen and the other will be for a button interface as well as status LEDs which will be mounted ...
1
vote
2answers
134 views

PCB's with Connectors

Are there any guidelines, standards or rules of thumb to follow when designing a PCB with connectors (USB, ethernet, etc.) that will need to fit into a case with a back panel? More specifically, how ...
7
votes
2answers
275 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
31 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
46 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
29 views

Eagle Clearance Error on DS2784

I am using the CAD drawing for the DS2777 from Maxim Integrated. ...
10
votes
2answers
739 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
59 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
152 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 ...
6
votes
4answers
468 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
80 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
37 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 ...
11
votes
4answers
848 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
43 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
85 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
744 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
115 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
112 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
215 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
320 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
153 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
110 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
67 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
64 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
129 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
133 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
593 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 ...