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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2answers
111 views

Enabling extra routing layers in Eagle (paid version) PCB design

I started a PCB design in the freeware version of Eagle, now I have the full version, but it won't let me route tracks to the extra route layers (i.e: only top and bottom). Starting a new design in ...
1
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2answers
73 views

How to measure the PCB size?

Can somebody share me your methods measuring the PCB size in CAM Software ? In PCB house ,we always measure the size according to the centre of outline and get the final size of the unit board or ...
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0answers
40 views

Circuit Certifications [on hold]

Finally got to the stage of designing some simple but useful circuits, I started to wonder how to certify my designs for commercial markets; several questions come to my mind Hoe many certs there ...
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0answers
25 views

How to use vias in Proteus ARES?

Thanks for reading this. I am building a 2 layer PCB. My question is quite basic. I just don't know how to use a via in Proteus ARES. I can place a via down, but then I cannot route tracks to it. ...
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0answers
38 views

Issues in thermal on PCB

i design one power supply board in that some coils are placed on the surface of PCB, that means in center surface of PCB. these coils are dissipating more than 7W on PCB. because of this PCB is ...
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1answer
123 views

Impedance matching with only capacitors?

I need to do impedance matching for 33 + j32 ohm source and 16.5 + j0 ohm load. The copper traces adds 99 ohm impedance and 20 degree electrical length. According to smith Chart below, I need to use ...
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1answer
28 views

How to determine dielectric constant and loss tanget of a PCB board at a specific frequency?

I need to know dielectric constant (relative permittivity) and Tan loss of a FR4 board at 2.45 GHz. The specification of the manufacturer is as it is below: Dielectric Constant: Test method ...
0
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1answer
46 views

Single regulator to power mixed signal PCB?

I have a codec (ADC & DAC) with both analog and digital power and ground connections (upper half is analog, lower half is digital). By placing the device package in such a way that all digital ...
4
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1answer
44 views

How to minimize characteristic impedance mismatches caused by vias?

This question springs from an answer here. When using stripline configurations for rf signalling, the conductors are routed on an inner layer of the pcb, sandwiched between two ground planes. I ...
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2answers
48 views

Which of these Stripline Impedance Calculations is correct?

Different sources are giving me drastically different characteristic impedance values, and am hoping someone will verify them for me. Generally, with microstrip, I start with an online calculator to ...
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1answer
174 views

Unable to delete Trace in Eagle

After running the design through the Errors Tool and moving a route that had insufficient clearance, I'm left with this blue segment that is overlaying the red route. Why is it there and how can it ...
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1answer
96 views

Requirements tools for PCB design?

I'm writing requirements for our PCB designs, determining what clients want and what's possible to build. When requirements are finalized, I write tests for the same designs. Right now, I'm doing it ...
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2answers
77 views

Pad hole size for 0.1" Male Headers

I created an Eagle part that has several holes to solder 0.1" pitched break away male headers to, such as the one below. However the pad has a hole thats too narrow for the header! What drill size ...
6
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1answer
68 views

Preferred balun location? (Are differential microstrips preferrable to single-ended?)

I'm designing a PCB with a transceiver that has differential signal pins for rf. These differential signals travel to a balun, which transforms them into a single-ended signal (50-Ohm ...
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1answer
83 views

How to create footprint from IC diagram when no recommended layout is given?

I'm a student trying to create a library part in Altium for an Analog Devices AD8232. Most IC datasheets give a recommended footprint to use, but the AD8232 datasheet only shows the IC itself: I ...
10
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3answers
947 views

Cleaning PCBS… using water?

I found this video where a technician with a lot of experience seems to clean his PCBs using water, and then he just puts it in the sun so it can dry. I was just amazed to see the circuit keeps ...
2
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3answers
228 views

Can differential USB traces be routed relative to Power (not Ground) planes?

I would like to route my USB 2.0 (12MHz) signal on the bottom layer of a 4-layer PCB. However, the edge-coupled microstrips would then be referenced to the power plane, not the ground plane. The ...
3
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1answer
64 views

Dual smart battery design and PCB layout

I have a system that is powered by a 7.4V Lithium-Ion battery. The system, which is a combination of processor module and sensors, draws a varying amount of current at varying voltages (5V, 12V, -12V, ...
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1answer
99 views

Is it bad to route a trace edge of a rectangular pad?

I got a quick friendly critic from someone in production for the below trace that I should not route the trace from the edge of a pad. What he said that it would create an extra force to the trace ...
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1answer
94 views

What's the purpose of the ground plane?

What's the purpose of the ground plane? I guess it's a pretty basic question and I tried to understand it by reading http://en.wikipedia.org/wiki/Ground_plane#Printed_circuit_boards but I still don't ...
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4answers
675 views

What is the purpose of holes on edge of the PCB?

Here is a photo of one of Texas Instrument's RF EVMs. Please pay attention to edge of the PCB that has multiple tiny holes. I marked 3 of them with a red circle on the photo. What is the ...
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3answers
40 views

How do you change the default via dimensions in Altium?

When I place a via, it always has a diameter of 1.27mm and a hole size of 0.711mm. I want all of my vias to be smaller and it's really annoying to have to change them manually EVERY time. I tried ...
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1answer
73 views

Can I split a PCB using Altium?

I'm starting my first PCB using Altium and I want to take advantage of small dimensions PCBs cost in order to make my PCB cheaper. As an example take the image below. On the left there's the full PCB ...
21
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2answers
927 views

'bridges' on a PCB copper layer

I've come across a design where each pad was connected using 4 'bridges' to the GND copper layar. What stands behind these 'bridges'? Why not make a full copper layer with only solder-mask defining ...
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2answers
106 views

SMD size 0805 vs 1206

Using SMD to make the PCB smaller is an easy choice but I'm wondering if using mainly 0805 size is really worth it compared to 1206. I don't want to store a mix of both. These are some pro and cons, ...
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2answers
46 views

Altium can't output NC drills file?

I'm about to send my gerber files to OSH park however I'm having trouble generating the drill file in Altium 14.3. The output file is some other format than the Excellon / NC Drills file that the fab ...
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1answer
86 views

Is it time to move from a 2 layer board to a 4 layer board

Below are two pictures of a portion of a PCB layout I did. The first shows the signal traces and the second shows the ground pour. U1 is an 8 MHz MCU, U3 an I2C sensor, U4 a RTC, and U2 a boosting ...
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3answers
353 views

How to connect large traces to pads in PCB?

I am designing a PCB, and 10 A-15 A current is flowing in a trace. I think a 300 thou track should be used for 1 oz Cu-thickness. I see that it is impossible to connect two pads ...
1
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1answer
57 views

Validation of power supply decoupling and oscillator connections in a PCB

I've been learning PCB designing lately to design a small controller board.The board has a micro-controller and its supporting components laid out as shown : . After having gone through some nice ...
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1answer
109 views

3v3, 12v Smps: “Design ok!” “Pcb ok!” Why not stable? Please Help

Im working on a project and i need 3v3,5v and 12V in this. I though smps circuits would be better than Linear Regulators. So i choose LM2676-adj IC. I designed schemetics for 3V3-3A SMPS and 12V-3A ...
1
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3answers
83 views

Via's in switch mode power supply

I'm using a TPS54386 and currently designing a PCB layout. The data sheet says to avoid via's within a certain loop; I was wondering what would happen or if anything would if I went ahead and placed ...
0
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1answer
58 views

How to connect pins with ratsnest connection after netlist transfer in Proteus ARES

I have a schematic file in Proteus-ISIS. I transferred into the ARES, after defining board edge and placing components, I placed 1x5 connector (CON5_1X5_U_FCI). But I could not connect pins of the ...
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1answer
84 views

Determine best op-amp order for PCB design

In my current design, I use 3 op-amps from a quad package (DIL 14). One is not used. For the design, it doesn't matter which op-amp is used when, since they should be identical. For example, I'm ...
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1answer
51 views

coplanar transmission line on both sides of a four layer board

I am designing a four layer board in which i have to run two 50 ohm traces one at the top and other at the bottom side of the board. I have decided to use Coplanar wave guide for both the traces. I am ...
0
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0answers
51 views

Improving PCB layout for regulator circuit

I've made a layout around an Allegro A4490 triple buck regulator, with four optimization goals: minimize loop area/change in area when switching keep the ground attachment of the input and output ...
2
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1answer
70 views

How to draw an elliptical PAD in Eagle

I am trying to design a PCB layout for a component which requires elliptical pads. I am trying to do it with two arcs but I didn't get an ellipse. Can anyone suggest how to draw ellipse on eagle? Is ...
12
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1answer
412 views

How to select FR-4 board thickness

The PCB manufacturing house that I use says the board thickness between 0.4mm and 1.6mm are the same cost (I have 2 layer design). What is the benefit of having thinner or thicker board thickness for ...
0
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2answers
74 views

Why is my circuit not providing the right voltage to my motor?

I have a circuit which is supposed to vibrate a vibrating motor. The circuit is fairly simple and uses a BJT to step up the current to the motor. The motor also has a capacitor and diode in parallel ...
7
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3answers
178 views

High Voltage PCB Design

I want to design a 4 layer PCB with the following voltage levels. GND, 5V, 3.3V and 80V. In the circuit there are some MOSFETs which are driven by 3.3V and MOSFET switch 80V (required current is very ...
5
votes
1answer
91 views

Placing Via's on PCB

I'm designing a PCB for USB 3.0, the specifications for Differential impedance comes at 90 ohms with a tolerance of +- 5 ohms. I've used different calculation tools but when I have to hold these ...
6
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2answers
208 views

Mounting hole on a PCB

Here is a picture of 3 mounting holes on three different PCBs. The red one is what I prepared on Eagle CAD and used "hole" button on the left side menu , something like this: Do I need to use ...
4
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2answers
82 views

PCB Panelization tool/SW and adding test connections

I prepared 4 different PCB layouts on Eagle CAD and generated Gerber files. As I can see Eagle CAD doesn't have any option to panelization. Is there any free tool/program that can allow me to ...
1
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1answer
67 views

Is there some PCB tool that exports to ISIS Proteus [closed]

I'm a CS student and I have to build a project in ISIS Proteus as a semester project, but Proteus' demo version does not allow to save the project. The project must be in Proteus because it is the ...
2
votes
2answers
280 views

Why we need the PCB Panelised for assembly?

I have a PCB finished in invidividual size for customer but they gave me comment that it can't be used by their assembly vendor and ask me make the new batch for them, When we make the board in 2 up ...
1
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1answer
70 views

Will crosstalk be induced if signal running in parrallel to power trace?

I haven't come across any mentions of signals running in parallel with power traces. Everyt mention thus far has been two signals to each other. If I have a low amplitude signal (sinusoid < ...
3
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6answers
373 views

Manually Drill Vias into PCB

As shown in the photo below, the PCB design was sent for fabrication without the drill data. Is it still possible to drill the via holes so we can save the PCBs? This is a 2 layer board, most of the ...
3
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2answers
110 views

Traces under 32kHz Crystal

I am working on a battery powered 2 layer RF design using a 32.768kHz Crystal oscillator with an Atmega328p micro controller. The crystal will run a timer in asynchronous mode as an RTC clock. My pcb ...
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1answer
102 views

Proteus, Ares, Isis - how to combine LYT and DSN?

I have inherited some old files from a Proteus project, .DSN and .LYT files. Is there any way of combining them into a project file so new Gerbers can be generated etc?
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1answer
73 views

Creating Custom Component + Pattern - Diptrace

Right now I am creating the schematic and the final pcb layout of my circuit in Diptrace so that I can etch the PCB myself. I am going to use LM2985-3.3 SMT LDO from Texas Instruments in my circuit ...
0
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2answers
89 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 ...