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

6
votes
4answers
127 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 ...
6
votes
2answers
428 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
0answers
32 views

Learning resources for electronics and PCB design [on hold]

I am an EEng graduate although I eventually took a software engineering direction through the last years. I've had the fundamental theory taught... Circuit analysis (Rizzoni), Digital Design (Mano) ...
2
votes
1answer
49 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
48 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
25 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
54 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
55 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
55 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
39 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
29 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
97 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
132 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
58 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
112 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
75 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
70 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
572 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
45 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
44 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
102 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
49 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
184 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
54 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
71 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
176 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
71 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 ...
3
votes
0answers
91 views

How to convert files from Cadence to Eagle CAD?

Is there any free software that can convert Cadence files (.dsn, .opj, .brd) into Eagle CAD files (.brd, .sch)?
1
vote
1answer
88 views

Proper PCB grounding with several general purpose ICs

I'm designing a general purpose Arduino shield pcb and right now I'm struggling to find a proper ground layout. ICs on the board: 12->5V and 12->10V @5A switching DCregulators, several H-Bridge motor ...
3
votes
3answers
280 views

50MHz SPI PCB routing, use vias or resistors?

I am trying to route the SPI between MCU and ADC. However, the pin orders between MCU and ADC are not matched, there are crossings. A four-layer board is used.(signal - ground - power - signal) I ...
1
vote
1answer
99 views

How should Ground vias be placed?

I am using vias to filter the input power. The following to pictures show two ways of placing vias. I think both of them are inappropriate since the vias are not "fully" connected with ground through ...
0
votes
1answer
70 views

Analog/Digital ground vs Power/Signal ground

Are these ground plane separations on a PCB equivalent, or if I am already separating my ground into analog and digital parts should I also divide it in power and signal areas?
1
vote
2answers
101 views

Analog and Digital Grounds on a DAC

I've read at several places (1,2) that ICs such a DAC have both analog and digital ground pins, both should be tied to AGND at the chip. However, the specific part I'm planning to use (MAX5104) does ...
4
votes
1answer
85 views

Calculating differential PCB traces - Edge-Coupled Microstrip

I finally have the microstrip characteristic impedance thing figured out. But now, of course, I need to learn about differential signalling on PCB traces. I've spent some time researching. Here is ...
6
votes
2answers
170 views

Should I keep the decoupling capacitor's vias isolated from ground fills?

I'm finishing up a PCB layout which contains a 6.5 GHz ultra-wideband transceiver with a chip antenna, an ARM controller running at 72 MHz with a 12 MHz crystal, a 16 MHz SPI bus with 3 peripheral ...
2
votes
2answers
172 views

Dimensions of TQFN-EP 48 lead package

I'm looking for the correct pcb footprint for the MAX1979 IC by Maxim, supposedly in a TQFN-EP package. While the land patterns are available on Maxim's website, there are apparently several 48 lead ...
2
votes
2answers
191 views

Learning PCB Layout Strategy

A number of projects I have been working on have outgrown the breadboard phase, and I have been learning how to do PCB layout. My first tiny project (a cable adapter) went smoothly, but as I have ...
25
votes
11answers
5k views

Why do we need so many transistors?

Transistors serve multiple purposes in an electrical circuit, i.e switches, to amplify electronic signals, allowing you to control current etc... However, I recently read about Moore's law, among ...
3
votes
2answers
145 views

Power origin and power planes placement on PCB

Although there are many similar questions to this one, I wish to get your attention to this specific board layout. The main power on the board will be 5V, and one of the layers is dedicated for ...
1
vote
4answers
305 views

Duplicate pins on an IC

I've realised that several ICs with simple components, such as the FDS6690, provide duplicate pins in order to comply with a standard IC package (e.g. SOT23). My question is - are these pins connected ...
0
votes
1answer
59 views

Ground type for DC regulator

When considering a simple DC regulator such as a Texas' LM22677 on a PCB, should it use the digital or analog portion of the ground plane? EDIT: Contextualizing, I have a 12V input feeding two ...
0
votes
1answer
59 views

Ground separation

I'm designing a small PCB for low-level light detection. It contains an Avalanche Photodiode (APD), the DC regulator required for proper biasing (from 5V to ~65V) and a transimpedance amplifier. My ...
4
votes
2answers
200 views

Decoupling with multiple caps per pin. Which should be closest?

I have an Ultra Wide Band transceiver with an internal power amp. This PA has two input pins for Vdd. According to the manufacturer, each of these pins should be decoupled with three caps; 10p, ...
7
votes
4answers
725 views

4 layer PCBs with Fritzing

Can you use Fritzing to create a 4 layer pcb? Also, in real life, what is the maximum limit of layers we can use to create pcbs? is it 4 layers?
5
votes
1answer
176 views

DDR bus design review

In our last build we had issues with DDR stability in our prototype, simply because of lack of experience with this type of high speed memory connections. We managed to get it working with halving the ...
2
votes
2answers
191 views

How to determine annular ring width for thru-hole pads?

When placing thru-hole components on a PCB, how do you determine what the annular ring width should be? For example, I'm making a PCB with a thru-hole switch whose contacts are 1.2mm in diameter. To ...
2
votes
4answers
208 views

Should mounting holes be plated?

When putting mounting holes for screws on a PCB, should the holes be plated or unplated? I've read plating the holes provides better support for the screw and helps prevent the PCB from being ...
1
vote
1answer
91 views

Which Eagle part to use for this 2-pin Screw Terminal?

This is my first EAGLE design and I'm looking to add some a number of 2-position screw terminals (3.5mm pitch) PRT-08084. Problem: I can find the EAGLE part for ...
1
vote
2answers
110 views

Layout of 4 layer PCB - pour?

I'm working on a 4 layer PCB with internal 2 layers being power and GND... 2 outside layers are signal. Is it better to have a pour on the outside layers or just leave them empty except for the ...
2
votes
1answer
84 views

How to route to a hidden pin in Altium

I'm using Altium Designer 14.2.3 and I have a connector on which are always two pins connected to each other. In my schematic library I have configured the Pins to be hidden and connected to the ...