Questions tagged [layout]

Layout is the process of designing a PCB including placement of parts and routing of traces.

Filter by
Sorted by
Tagged with
2
votes
2answers
4k views

Convert .PCB (Protel) to .MAX (Orcad Layout)

I need to convert a .PCB file created in Protel to a .MAX (Orcad Layout) file. I tried importing by using Layout Plus, File->Import->Protel PCB, but I got an error. Here is what the .LOG file ...
10
votes
3answers
10k views

Blind/buried vs. through hole vias?

I'm trying to learn PCB design and, from what I've read and seen, there appear to be three different types of vias: Through hole - goes all the way through the board Blind - goes from the top or ...
5
votes
5answers
7k 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 ...
7
votes
3answers
1k views

Want my PCB design to work right the first time!

Just finished a design of a 8-Layer PCB, the highest frequency is 125MHz. I want this design to work right the first time, how should I revise the design and what should I take care of? Something ...
2
votes
1answer
794 views

Multiple radio in a small dimensional sensor node PCB

I'm planning to develop a wireless sensor node that equips dual IEEE 802.15.4 radios. Although the board will equip homogeneous dual radios, both of them will operate at different channels. Regarding ...
22
votes
4answers
17k views

Are there reasons *not* to have a copper-pour ground plane on a PCB?

I am taking a first stab at designing a PCB from scratch. I am considering using a CNC mill fabrication process, and it seems like with this process I would want to remove as little copper as possible....
20
votes
6answers
29k views

How do I facilitate keeping multiple grounds, (i.e. AGND, DGND, etc…) separated in the layout when using Eagle?

I've designed several PCBs where I needed to keep the ground returns of different parts of the circuit separated, i.e. analog, digital and high power. I use Cadsoft Eagle for schematic capture and ...
2
votes
1answer
494 views

how to design a power amplifier's layout in l-edit?

i want to design a power amplifier in Tanner L-Edit. I want to write code in the .ext file but I don't know what syntax or language the .ext file is expecting. Is it spice? I couldn't find a good ...
9
votes
3answers
4k views

DDR1 Layout Considerations - DOs and DONTs

I am novice to high speed design. Before getting in to DDR, I recently learned about impedance matching and how it is done, likewise I learned about length matching and how it is done.(Baby steps ...
13
votes
1answer
2k views

TVS Diode Layout

I have two DB37 connectors on my board which ultimately connect to a CPLD. All of these connections/signals are inputs to the device. To protect from ESD I am using TVS Diodes ESD9C3.3ST5G. I have ...
9
votes
1answer
3k views

Why is a broken ground plane not as effective as an unbroken one?

I did a two layer board a few weeks ago which had a dedicated ground plane. I routed 90% of the signals on the top layer and for the last 10% I had to route them through the bottom (ground) plane. I ...
0
votes
1answer
779 views

how to design an inductor in Tanner L-edit and extract the designed layout in L-edit to S-edit?

hello i am trying to design an inductor in L-edit. i thought to use metal1 layer and make a squares in it for example 5 squares while there is a free hole in the center of them. actually i don't ...
30
votes
5answers
24k views

What is causing large oscillations in my DC/DC boost converter? Is this ground bounce or some other effect?

I designed my first PCB for a DC-DC boost converter only to find that it produced very noisy output. The design is based around the MIC2253. Here's a schematic: Although my circuit allows for ...
4
votes
3answers
11k views

AC coupling on PCIe layout

I'm working on a layout in which two chips connect to each other through a 1x PCIe bus. The two chips are on one board. One of the chips is the Xilinx Spartan6 LX75T so I've been working with the ...
4
votes
3answers
13k views

How should I set up my text in Eagle for the maximum chance of success?

I've just finished routing a board in Eagle, and now I want to work on the silkscreen and texts. I have a few questions, however: I chose "always vector font" before I did anything, but my texts ...
24
votes
1answer
4k views

PCB layout questions for MCU breakout board

I'm attempting to route a board that is, essentially, a breakout for the LPC23xx/LPC17xx MCU. I've never routed anything approaching this complexity before, and I have a few areas of concern. I know ...
6
votes
3answers
1k views

Controlled impedance in presence of vias and through-hole components (PTHs)

We have some controlled impedance traces on layer 4 of a board. Layer 3 is a GND plane. Layer 5 is a 3.3V plane. Both planes are unbroken (they occupy the entire layer), with the exception of vias and ...
109
votes
6answers
48k views

Should chassis ground be attached to digital ground?

I'm working on a PCB that has shielded RJ45 (ethernet), RS232, and USB connectors, and is powered by a 12V AC/DC brick power adapter (I do the 5V and 3.3V step down on board). The entire design is ...
27
votes
5answers
12k views

Standard PCB Layout Book

Are there any good references on advanced PCB design/layout/routing? There seems to be a large wealth of circuit design books, books about RF PCB design, and books dealing with high-speed digital ...
2
votes
1answer
1k views

Criticize SMPS PCB Design

Yes, it is me again with a PCB Design. I am learning a lot thanks to you. This time, the specs are; 10-32 V input 35V 4A output Boost converter The controller IC is LM3478. Schematic & PCB: Q1 ...
2
votes
3answers
711 views

Guidelines on branching of a PCI express signal

We have 3 PCIe slots on a board, let's call them A, B and C. On this board, slot A will always be populated with a PCIe device, however, among slots B and C, only one of them will be populated. There ...
2
votes
1answer
2k views

SMPS PCB Design Critic 3

Can you critique my design? After finishing my 5v part, I've added the 35V part, too. 10-32V to 5V 1.2A SMPS Buck Regulator, the IC is IFX91041 from Infineon. 10-32V to 35V 4A SMPS Boost Regulator,...
2
votes
1answer
1k views

SMPS PCB Design Critic 2

Thanks for your patient help, I am learning a lot. This is my (final, I hope) re-designed layout. What do you think? 10-32V to 5V 1.2A SMPS Buck Regulator Design. The IC is IFX91041 from infineon. ...
2
votes
3answers
6k views

How do I look at all the footprints in a KiCAD library?

In the KiCAD PCBnew layout editor, is there some way to see what a footprint looks like before I place it? Or am I forced to select a footprint that has a plausible-sounding (ASCII text) name, place ...
9
votes
3answers
4k views

SMPS PCB Design Critic

Oldest versions of this post can be viewed through this link. This is my re-designed layout. What is your view again? 10-32V to 5V 1.2A SMPS Buck Regulator Design. The IC is IFX91041 from infineon. ...
5
votes
4answers
2k views

Do I need a decoupling cap for ICs that do not switch very fast?

I am designing a space and cost constrained layout. On it I have two analog muxes (ADG719 (datasheet) or similar.) Both switch states a maximum of two times a second. They do carry video signals with ...
1
vote
1answer
324 views

Design advice when daisy-chaining multiple JTAG devices

I know that JTAG was specifically developed to support daisy-chaining of multiple devices, but I am still worried that my board will show up and I won't be able to talk to one of the devices because I ...
4
votes
5answers
8k views

Board layout help: 64-output Mux! (for possible use in 8x8x8 LED Cube)

So just for practice I decided to design a 64-output mux in Eagle, I figured if its good it could be useful in the future. I did not use auto-router. Here is the PCB: (Click to zoom in) To the ...
18
votes
5answers
3k views

Can a switching power supply be built on a breadboard?

I'm toying with the idea of putting together a switching power supply (my first), using something like the LT1076-5 or the LM2576 controller ICs. These ICs have low external parts counts, and a ...
21
votes
6answers
7k views

What's the schematic to share one crystal with two micros?

How do I share a single crystal (not a complete oscillator module) between two micros? Is it OK to just connect everything as normal for the first micro and also directly connect its XO to the XI of ...
228
votes
9answers
80k views

Decoupling caps, PCB layout

I guess I've been somewhat ignorant when it comes to the finer details of pcb layout. Lately I've read a couple of books that try their best to lead me on the straight and narrow. Here is a couple of ...
6
votes
2answers
6k views

What are the drawbacks to a Vcc (positive voltage) plane?

I'm familiar with using ground planes when designing circuit boards. I've started used power planes for the predominant voltage in a couple of my designs, and I'm wondering if that's a bad idea. I'm ...
6
votes
4answers
4k views

VCC trace routing on a two-layer board with TQFP chip

I'm just trying to layout a PCB with CY7C68013A (100-pin TQFP) on it. It's a sort of experiment, so I'd like to use 2-layer PCB, 4 layer PCBs are just too expensive. This leads to some interesting ...
8
votes
6answers
6k views

Adding a small protoboard-like area to a PCB

I'm currently laying out a PCB in eagle for a circuit that will form the basis for some experimentation. Instead of adding a row of headers so that I can plug it into a breadboard, I figured I would ...
3
votes
1answer
1k views

Polygons pours under BGAs?

Is it a good practice to put polygon pours on the top layer underneath a BGA? I've occasionally got several GND or VCC pins in a row/column, and I'd like to pour around them all. I've got the same ...
2
votes
2answers
493 views

Why are breadboards laid out in strips of five?

The canonical breadboard layout consists of two strips of five contact points for every column, separated by a divider that allows you to accommodate DIP-style ICs. Is there a special reason why the ...
8
votes
1answer
27k views

How do I install a KiCad schematic or footprint library?

After I download a KiCad schematic library or footprint library -- such as the ones from http://kicadlib.org/ -- how do I use it in my schematic and layout? Should I install that KiCad library file ...
1
vote
1answer
188 views

Measuring temperature of microcontroller and other large ICs

I'm going to be using a microcontroller and SDRAM IC in an enclosure that could, given some environmental variables that I have no control or knowledge of, get too hot for the devices to work properly....
11
votes
5answers
6k views

How to connect decoupling capacitor when VCC/GND pins aren't close

I'm making a board which will host an ATmega 162 microcontroller in PDIP package. Unfortunately, VCC and GND pins are diagonally arranged. From what I've read, the capacitors should be as close to the ...
18
votes
4answers
4k views

Can I run traces through “No Connection” pins?

Several ICs are manufactured in packages with more pins than it supports. For example, the LM317 in an SO8 package has 4 VOUT pins and 2 N/C (no connection) pins. I often want to run traces through N/...
6
votes
3answers
1k views

Breadboard component layout design

What techniques are useful when layout a circuit on a breadboard? Specifically, making it as least cluttered and readable as possible. My circuits always come out looking horrible and really messy. ...
13
votes
3answers
16k views

Ethernet Layout Guidelines

I'm working on a DC jack powered Ethernet design and I've downloaded many Ethernet Layout guidelines from many semi vendors with varying recommendations. I've read app notes recommending almost every ...
10
votes
9answers
3k views

Schematic capture/PCB layout program recommendations [closed]

I'm still using PCAD2006 for my schematic capture and PCB layout. I'm not very happy with this; it is rather buggy, but it's a leftover for which I have an extensive library. Due to the problems I'm ...
5
votes
4answers
1k views

What precautions should I take when mixing analog audio and digital on the same board?

What precautions should I take when mixing analog audio and digital (uC control) on the same board? I don't want to hear the I2C bus in my speakers. I'm thinking about Separate power supplies ...
9
votes
3answers
4k views

Using oblong / rounded surface mounted pads for chip resistors, capacitors and inductors

I'm learning to layout PCBs and lately I came across practice that made me curious. The chip passives' pads are etched with oblong / rounded shape, instead of rectangular shape that is used in all ...
4
votes
2answers
359 views

Layouts - would a joint at 1 point, or 2 be the same?

I'm currently trying to lay out my first from scratch project on veroboard. While I get connecting things in series and parallel I'm trying to work out if a + shaped connection and a pair of + shapes ...
7
votes
5answers
14k views

How close is too close for traces on a PCB?

Are these traces too close for conventional PCB manufacture? DRC check advises against it, but I haven't filled out all the settings for it. For scale, the resistors are all 0603.
45
votes
6answers
130k views

Standard PCB trace widths?

Is there a standard for the sizes of PCB traces? That is are some 25 mil and others 10 mil or is can you choose your own? I plan to run 400mA through some thicker traces, but less than 30mA for all ...
16
votes
4answers
3k views

When laying out circuit board traces, what impedances do I need to consider?

I do low-speed circuit design for microcontrollers and such (usually at less than 20 MHz), and now I'm getting started on some more high-speed circuits. What I want to know is: What considerations ...
60
votes
12answers
75k views

How to connect USB Connector shield?

How should I route USB Connector shield on PCB? Should it be connected to GND plane right where USB is placed, or should the shield be isolated from GND, or should it be connected to ground through ...

1
8 9 10
11
12