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

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Oscillation on an 4 phase 12 to 24V 20A boost inverter

Oscillation on an 4 phase 12 to 24V 20A boost inverter I’m using 2 pieces of LTC3787 to make a 12-24V inverter. I made a 4 layer board from it to have enough ground to make sure all will be stabile. ...
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73 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 ...
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136 views

PCB RF Layout Critique: Input on my radio-telescope PCB

I'm attempting to do the board layout for a radio-telescope we're building at one of my jobs. Here is the overall system topology: QRFH is for "Quad Ridged Feed Horn". It's a rather esoteric ...
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55 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 ...
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59 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 ...
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36 views

LPC1768 LQFP package outline and footprint solder pads

I was double checking footprints of my design before I send it to prototype manufacturing. When I check LPC1768 package outline and footprint I saw that first solder pads on every corner is wider ...
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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 ...
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146 views

How do I make multiple connections to a microcontroller's GND/VCC etc?

If I'm hanging a number of switches and potentiometers and other sensors off a single microcontroller, I need to connect multiple wires to the µc's ground and VCC pins. What's the best way to do ...
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212 views

High EMI PCB track under transistor or diode package

Can a high EMI PCB track under a transistor or diode package (in this case TO247AC) be a problem? To get a better understanding: Is there any advantage on putting these tracks on the other side ...
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196 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 ...
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177 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 ...
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88 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 ...
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151 views

Should you try and minimize via quantity?

I have a 6.5" x 4.5" double sided board that is mixed analog and digital. I have partitioned the analog and digital grounds from each other and have zero ohm resistors that bridge the two grounds ...
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80 views

What does “50 ohm system” mean?

I'm looking to use the following switch to switch an SPI bus ( CLK <= 2Mhz) between two different devices. I'm reading the datasheet to see if the the frequency of the signals are going to be ok, ...
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118 views

Proteus/Ares - how to scrap old layout but keep Isis schematic

I have got in a mess on the layout. I want to scrap the existing layout and restart with a new board size. How do I do that without restarting the entire project?
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54 views

Integrated Circuit Multiplier Circuit Problem

I'm developing an 8bit x 8bit IC signed multiplier using FULL adder cells. Once I get partial products, I add them together. The problem I have occurs in this stage, adding of the products. This is ...
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41 views

Cadence SoC encounter

I am trying to create the layout of my design for an 8 bit multiplier accumulator in SoC Cadence encounter tool. After routing the design using wroute command, the ...
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190 views

PCB layout for 8-16MHz crystal very near WiFi module AND small DC motor

I'm designing an "Internet of Things" appliance where space and layout are constrained by mechanical and cost requirements. The main processor is a PIC18 and its crystal (probably 8MHz, maybe 16) is ...
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229 views

1bit Full Adder Cell in IC not working as supposed?

I got an adder cell, which in IC mirror layout is this: EDIT: Transistor-level, standard adder circuit: Which I actually made in IC like this: It's not working as it should! I labelled it ...
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122 views

Integrated Circuit Layout Design - Dynamic Flip Flop?

I need to create a dynamic flip flop like this: In integrated circuit technology, at mask layout level. I then want to create an 8bit register, using 8 of these flip flops, with a common CLK ...
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428 views

Designing for High Acceleration

I'm looking into designing a board for a robotics application that is going to be spinning very quickly, and am wondering if there is anything special to take into account. It's going to be in the ...
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108 views

Orcad Layout plus 10.5 RCA Footprint

I am new to Orcad 10.5 and I am designing a PCB. I used an RCA jack in my project but I can't find an RCA package in Layout Plus. Can you help me with this problem?
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46 views

Layout and Capacitance of 24/12 Inverter

Consider below layout: It is brought from CMOS VLSI Design Book by West-Harris. Why it is called 24/12 lambda inverter? I could not estimate its width/length so it match 24 and 12. Why its ...
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215 views

Power Resistor TO-263 in Layout (Eagle) [duplicate]

I am using this Power Resistor here and I am trying to put it in my layout. The Problem is I can't find any .lib (TO-263 or D2PK) file in Eagle or at least a similar package. Any Help?
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99 views

How to connect GND and AGND planes on an inner layer in eagle?

This is an follow-up question to "How do I facilitate keeping multiple grounds, (i.e. AGND, DGND, etc…) separated in the layout when using Eagle?" I like the idea of using a "virtual short" component ...
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73 views

Building a SMT footprint for a MSOP

I'm putting together a board and it's requiring a footprint for a 16 lead Plastic MSOP. Usually I try to dig around and find a manufactures recommended footprint and try to stick with that. I figure ...
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138 views

SFH6916— SOP-16, Half Pitch Mini-Flat Package eagle library needed

I want to use SFH6916 ( Optocoupler, Photo-transistor Output, Quad Channel, SOP-16, Half Pitch Mini-Flat Package) in my circuit. I am using Cadsoft Eagle for layout designing. The package ...
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143 views

Would I need a star topology with a dedicated ground plane?

Some background: I have a PCB with a bunch of relays on it. The purpose of the circuit, is to allow signals to pass through from one connector to another (db37), or to stop it - that's where the ...
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275 views

Crystal, PCB Layout

I've completed a few circuit board layouts before, however this is my first time doing a layout with a oscillator/MCU. After doing some reading (via this site and datasheets) I've come up with the ...
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91 views

differences between different footprint surface mount RLC components

This is my first question here and I am new to board level digital design(I have years of experience on programming development boards though). So here is my question, what are the differences ...
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142 views

What tool can make a nice 3D image of a via?

I found this graphic somewhere on the web, but now I need to create a similar illustration for some training, but with a 16 layer board having traces coming in on other layers etc. What is the ...
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752 views

Choosing a SDRAM pcb layout

I'm working on a project with the quite new STM32F429 in LQFP208 package. I need to solder the first couple of prototype by myself for low budget reason. I choose this package so I could check myself ...
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47 views

Difference between MIL and IPC footprints

I've always noticed the different MIL and IPC footprint libraries in CAD tools. Usually, the pads are slightly different sizes. What is the reason for the difference? Tolerance? Quality assurance?
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139 views

Return Paths of Parallel FETs

I'm attempting to design an H-Bridge which can supply 24V at 60A. As 60A is a lot of current I decided to parallel upto 4 FETs per leg to split the current. I am using a MIC4102 2A driver to drive ...
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1k views

Can Proteus Isis open Eagle's schematic?

I had some years working with Proteus PCB design. A few years then, I did not do the same work. Now, from Googling, electronics community seem to place Eagle in a dominating position. Sparkfun, ...
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112 views

Explain Orcad Layout Plus 9.2 Layers?

There are total 18 layers in Orcad Layout Plus 9.2 Can someone explain me the purpose of these layers? Which layers are neccessary when making a via? Thanks!
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345 views

(Layout Plus 9.2) How to copy a part from one MAX file to another

I have a Layout Plus 9.2 file. I want to copy some components on it to another file (I don't have component library). How can I export those components to a new library? How can I copy them to a new ...
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77 views

Eagle: Circular area under component colliding with traces

I am creating a PCB layout in Eagle and I noticed that when I add in the ground plane, there are two unfilled circular areas under the usb mini type B socket. Does that area need to be empty? I ...
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181 views

Component libraries for schematic and layout design

I've got much difficulties to find the footprint for the components I have in hand: They don't have name (I buy them at somewhere similar to flea markets). Therefore, their proper footprints are ...
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132 views

Eagle converts board to schematic

There are times that a design is given constraints in the placements of components. For me, I would like to start from placing them first before creating the schematic. Is there such a capability in ...
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756 views

Minimizing Ringing in a H-Bridge

I am designing a H-Bridge based DC-DC Converter that boosts 24V to 350V DC. I use a HF transformer at the output of the H-Bridge for the actual boost. The circuit works OK for a while and then the IC ...
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102 views

PCIe branching - Requirement of Switch

Considering the following scenario: A designer wants to connect 3 devices on a PCIe x4 finger edge connector, commonly found on mother boards. All 3 devices will be populated on the same PCIe card. ...
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261 views

Changing pad shape/size selectively on an inner layer in Eagle

I'm trying to create a plated cutout in eagle for a DC barrel jack connector (https://www.sparkfun.com/datasheets/Prototyping/Barrel-Connector-PJ-202A.pdf) for a 4 layer board to be fabed by oshpark. ...
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97 views

How to ground pins on a multilayer board with a ground plane?

Let's say I have a multilayer board with a single dedicated ground plane. Should I place all the grounds directly to the plane with a via as close as possible to the pin/pad or should I be looking ...
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166 views

Eagle layout: how do I create an elongated hole under IC for isolation?

I am kind of new to Eagle. I need to put a hole under an IC for isolation. An elongated oval to separate the sides of the chip. I need to be pointed in the right direction.
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542 views

Can I transfer Ultiboard files to other PCB layout software packages via DXF export/import?

I have an extensive library of PCB layouts in Ultiboard format. If, hypothetically, I wanted to switch to another software package, this would pose a problem, as the Ultiboard layout format appears to ...
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365 views

EAGLE CAD: Push aside traces by DRC clearance

Does anyone know of a script or tool which makes it easier to 'push aside' traces when routing by the specified DRC spacing? For example, if I have 2 traces which should be parallel and are 6 mils ...
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301 views

Universal smd pad size, bad idea?

I'm working on an open source filter design where the PCB can be reused for many future designs. It is based around a Sallen-key filter since a few changes to the capacitors and resistors can change ...
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153 views

How are these LCC module pads laid out?

It seems like there's something missing. I can't figure out how the rows are spaced relative to each other. The pitch is 1.257mm. The distance between the centers of 17 of them is 20.112 -- that ...
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126 views

What is a switching node island?

I was reading the LM2734Z datasheet and in the PCB Layout Considerations section, it says "There should be a continuous ground plane on the bottom layer of a two-layer board except under the switching ...