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

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6
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1answer
92 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 ...
0
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2answers
65 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 ...
1
vote
1answer
65 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 ...
16
votes
1answer
402 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 ...
0
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0answers
53 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?
0
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1answer
29 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 ...
0
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2answers
56 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?
0
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0answers
57 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 ...
0
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1answer
58 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 ...
0
votes
1answer
72 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 ...
1
vote
1answer
82 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 ...
4
votes
1answer
201 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 ...
2
votes
2answers
58 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 ...
3
votes
2answers
123 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 ...
4
votes
1answer
332 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 ...
0
votes
0answers
44 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?
3
votes
0answers
93 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 ...
1
vote
1answer
709 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, ...
0
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0answers
69 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!
1
vote
1answer
117 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 ...
1
vote
0answers
74 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 ...
0
votes
2answers
126 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 ...
0
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2answers
82 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 ...
3
votes
2answers
438 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 ...
1
vote
1answer
79 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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2answers
140 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. ...
2
votes
1answer
89 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 ...
4
votes
2answers
105 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.
3
votes
1answer
242 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 ...
2
votes
1answer
222 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 ...
6
votes
3answers
254 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 ...
3
votes
3answers
128 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 ...
5
votes
1answer
119 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 ...
7
votes
1answer
406 views

Placement/routing of decoupling cap straddling oscillator guard ring on dsPIC

Changes in my design are forcing me to replace my 44-pin dsPIC33FFJ16MC304 with a 64-pin (same package size, finer pin pitch) dsPIC33FJ64MC506. In the datasheets for both chips, Microchip recommends a ...
6
votes
3answers
710 views

Is it better to have a poor top layer copper pour or no copper at all?

For a few small 2 layers boards I'm doing, I'm using the top layer for parts and signals and a ground pour on the bottom layer with no or very short traces, based on comments and answers to my ...
1
vote
1answer
202 views

Routing the circuit for a snubber diode on a PCB?

I understand that the "ideal" place for a snubber diode is across the terminals of the inductive device that generates the flyback. But in the interest of making my PCB design for an Arduino shield as ...
1
vote
1answer
97 views

Eagle: How do I make a component from a board?

I recently discovered the fantastic Arduino shield components in LadyAda's latest Eagle library. Now of course I'd like to make my own, using the mechanical layer from an existing Eagle board file. ...
2
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2answers
201 views

XML schema for electric circuits

Is there any XML schema to describe electric/electronic circuits? I am thinking of something like a netlist, but using XML markup.
3
votes
1answer
272 views

Power Plane and Decoupling Capacitors Routing

Forgive me for my simplicity. I'm just a hobbyist and not an engineer by trade. I am trying to make my first 4 layer PCB in Eagle and I have a question I cannot find the answer to regarding power ...
2
votes
2answers
101 views

Groundplanes for Wideband synthesizer

I'm build a synthesizer (up to 2GHz) and got a questions regarding the gound planes (analog vs. digital). According to the datasheet (p. 7) some pins must be connected to analog GND, ex. pin 10 must ...
0
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2answers
134 views

Circuits newb needs someone to help with a diagram

I'm trying to build an OBDII circuit for a STN1110 chip from OBD Solutions. My problem is I don't understand some of the values needed. For instance, the datasheet has most of the information I need, ...
8
votes
1answer
429 views

Is there a PCB-layout related reasoning behind DDR memory package and footprint?

BGA DDR packages have a unique footprint. There are two columns of pads on both sides of the device, and an empty column in between. Is there a reasoning behind the placement of these pads (in ...
-3
votes
1answer
338 views

PCB footprint of Xilinx Kintex 7 FPGA [closed]

I am laying out a board with a Xilinx Kintex 7 FPGA (serial number XC7K70TFBG676). The first step is to create a footprint of the FPGA for my layout tool, the Cadence Allegro PCB Editor. Does Xilinx ...
2
votes
1answer
217 views

GPS module antenna shielding

I am designing a PCB including a GPS module. I am using the Locosys LS20031 which has a antenna mounted on it. The module is mounted on the board with 1" plastic studs and a connector connects it to ...
4
votes
2answers
217 views

EMC Design Precaution

I'm designing a simple circuit which will charge a big capacitor for 3 seconds, then pass a 5A current for few microseconds, then charge again the big capacitor for 3 seconds, then pump again 5A for a ...
6
votes
5answers
372 views

Feedback on this PCB

May I ask your comments on the layout below? Specially the via under the MCP16322. The layout is still missing the connector for the in/out voltages, but would love to have your opinion at this point. ...
3
votes
1answer
97 views

Name for circuit with multiple paths with aim of reducing inductance

Trying to find the best way of describing a circuit that uses multiple separate physical paths to reduce effect of inductance on by HF signals. Is there a term for such?
7
votes
1answer
488 views

How good is my xtal design on my pcb?

I'm designing a board for a school project using eagle. I thought I could get away with using the onboard clock of the PIC18 since it's not doing a whole lot (mostly just LEDs), but one of its tasks ...
4
votes
1answer
811 views

How to connect ground planes together

What is the best way to connect ground planes together ? I know that ground planes are connected together at multiple locations in order to keep a low impedance GND across the whole board and provide ...
1
vote
2answers
371 views

Video Composite signals

What are the considerations for PCB layout, and connector selection for video signals. Is it necessary to follow 75ohm impedance criteria in a closed system. The pipeline starts at Sony FCB IX 11 A ...