Questions tagged [pcb]
PCB is the acronym to Printed Circuit Board. A PCB is a carrier for the circuit's components and their electrical connections.
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FPC design Flex PCB
I want to design a flex PCB to stick a membrane keypad onto the back of a regular PCB. We want the two sections: one for power, LEDs, etc., and one flex PCB for just the keys.
How may I design the FPC ...
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Different trace/space rules for copper pour than for traces?
I recently ordered a 4/4 mil trace/space board from a new manufacturer who is geared towards very low-cost prototype manufacturing. They manufactured the first board I sent them with no issues.
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Serial to USB aggregation with Pi
I'd like to aggregate 4 serial devices to a single USB device (a rPi zero with only 2 UART).
So far, I've been able to design the following schematic but I'm not sure of the components used nor if the ...
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Voltage drop in OPAMPS [closed]
I designed a PCB to monitor temperature, pressure, voltage and current. To monitor the temperature I am using thermistors conditioned with a voltage divider, the output of the divider goes to the ...
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Charging IC for a 1S or 3S Li-ion battery
I have quite specific problem; I'm designing a PCB for my robot, that is used the main board for controlling motors, gathering data from sensors, etc.
The whole PCB will be designed as a Raspberry Pi ...
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Altium: Exclude entire layer from Clearance Rule
I'm designing a PCB in Altium Designer. I've defined Clearance Rules for certain nets. When I run the DRC (Design Rule Check) I get errors that the Clearance between the Keepout and the Pad doesn't ...
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How to read schematic for PCBs [closed]
How do I learn to read a schematic and understand the function and how the circuit work? Where can I find information about the schematic symbol and how it work and why some circuits look the way the ...
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Pull up or pull down resistor for potentially unused inverter input?
I'm using this TI Inverter that mandates that the unused inputs never float.
Sometimes, the inputs will NOT be used, and other times, all 6 will be used.
As such, it seems like I should use a pull up/...
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Should two different DC power supply GNDs be connected to each other on a PCB?
I'm making a small project that drives a few DC motors with H-bridges.
+12V DC will come from one DC power supply (regulated to 10V for motors,) and then +5V will come from another (different) DC ...
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Reverse engineering an printer rotary encoder [closed]
I'm trying to make an diy steering wheel and I have an encoder (I know the pinout). Will it be ok for this?
https://es.aliexpress.com/item/1005002435277981.html
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Earth for custom POE+ board design
after getting the center tap pins for poe, I have an example schematic to design an EARTH ground. I have the understanding that that would be our Earth in AC over cabinet. That would remove our value ...
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Inductor sign with single line on the top
I am new to schematics, so can someone help me understand what this part of the circuit means? What does "FB" stand for there, and which components should I use? I guess these are inductors, ...
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FPGA output timing explained
As a hardware designer you have consider the timing constraints of both the input and output device. Input devices specify a setup and hold time reference to the clock (the time in which the data ...
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STM32H7 flashing problem
I have been having a problem with my STM32H725IGT custom PCB, because I can't flash it even though i tried almost everything. I have tried flashing from nucleo's programmer and from stlink-v2 clones ...
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FFC connector with solder terminals on cable entry side
Are there any FFC connectors that have all solder pins on the same side as the FFC slot (i.e. where the FFC cable is inserted).
I know in most situations / designs this wouldn't make any sense, but I ...
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Attempting to patch the "G75 Bug" on a Gerber Level
Context
I am currently looking for alternative PCB manufacturers for my company and have sent Gerber files to some (Chinese) companies.
These Gerber files have already been used in the past by various ...
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How to specify the stiffener for ordering Flex-PCBs at JLCPCB
I have a Flex-PCB design that contains several areas that are supported by stiffeners. I am trying to order the PCB at JLCPCB but can not figure out how to specify the areas where the stiffener is ...
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PADS for land pattern coilcraft
How can you even make a footprint/ land pattern with this info. Is that land pattern the pads? Is that a wire going into the model, meaning my pad just needs to touch either side of the component? ...
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Identifying IC used in keyless entry module of automotive board [closed]
I am repairing a PCB board and need a datasheet for 8-pin IC with top marking BZAENA for replacement. Its dimension is 4.9 x 3.9 x 0.9 mm. This IC is used in a keyless entry module.
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Do non-polarized capacitors need to be in any type of orientation?
I have submitted my PCB design to JLCPCB for population. They are asking me if the orientation of my capacitors are correct:
My PCB and schematic of it:
In the datasheet it states that these are non-...
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Do you put a ferrite bead on both the positive voltage and GND trace?
I'm designing some basic DC power filtering for a very simple PCB. Do ferrite beads go on BOTH the positive voltage trace AND the GND trace, or should GND be completely free?
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Do we need to guard the input traces of an audio power amplifier?
This is a continuation of this question. I am using an LM4670SD/NOPB in my design. The IC has a 5 V supply.
The input of the power amplifier (+IN & -IN) comes from a smart module from Quectel.
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Audio Power Amplifier Layout clarifications
I am using LM4670SD/NOPB in my design. The IC is working at 5 V supply.
This IC requires an 8 Ω speaker.
My first question is,
In that case do the lines Vo1 and Vo2 needs a differential impedance of ...
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What is the best way to use 0 ohm resistors for a large number of signals?
I'm fairly new to PCB design, so maybe I start with a basic 0 ohm resistor like this:
I have both output pins (SLEEP & RESET) on the DAC chip. I want to have two options on my PCB, one with 3-pin ...
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How to decide the number of layers? [duplicate]
I am new to PCB design and I want to understand how exactly we should select the number of layers. I just know more layers helps us with making the routing easy but I don't understand what is power ...
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Astable Multivibrator Not Oscillating
I've been trying to get the Astable Multivibrator Circuit to work for a long time now, and I think I lack the knowledge to understand what's going on here.
The situation is as follows: I've checked ...
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PCB from circuit diagram [closed]
Can anyone please explain why this U1A and U1B is there and how can it be converted into a schematic in Easy EDA?
(Source: https://m.media-amazon.com/images/I/610mQaFartL._SX522_.jpg )
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What is this comparator in the Arduino Uno Revision 3 doing?
I was looking into the schematic of the Arduino Uno Rev3 particularly the built-in on board LED (connected to pin 13) and was curious about what was happening.
Here you can see pin 5 of port B being ...
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ESP32 custom board review
I have just finished the electronic design of my project and would like to request a review from anyone with more experience in PCB design. It's a custom development 2-layer board based on the ESP32-...
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Altium PCB Dashed Lines
I'm using Altium version 22.6 and I am wanting to add dashed lines on my PCB on the "Top Overlay" layer. I've seen plenty of references to dashed lines on versions 21 and before but none ...
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PCB design for Renesas' DA7212 audio codec
I'm designing my very first PCB. I managed to route all my components and I'm stuck at the last footprint - DA7212 from Renesas:
Those balls are both incredibly tiny and packed dense. I'd need a ...
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ESP32-WROOM-32E Custom PCB Failure to send LoRa Packet
I am having troubles trying to send a LoRa packet to a receiver. In the serial monitor I am stuck in the while loop and it keeps printing dots. Below is my code and I will attach a photo of the eagle ...
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How can I protect this gate signal trace from EMI?
I'm designing this board which will control current through a coil using an IGBT. The coil is 500 uH and is mounted around 3 cm above the PCB and will handle peaks of 400 A. Because of the close ...
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The output of ADC (AD7091R-5) is slowly rising with constant input
I have a circuit board with an AD7091R-5 analog to digital converter. I'm reading the output via I2C using a particle board (much like an Arduino.)
I'm reading the register for channel 0 and 1 as I ...
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How much clearance do I need for a terminal block that will run at 240VAC, 10A max?
To start off, I don't have any experience with designing PCBs for high voltage relays/switches.
I'm currently designing a PCB that has a relay on it that will be used to turn on and off a device (like ...
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Short circuit of voltage regulator
I am trying to design a circuit to get an amplified signal out of an OPT101 photodiode.
The photodiode contains an amplifier (and there is an additional opamp for further signal amplification on the ...
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Continuous load with wireless charger
I have a wireless charger module as seen in the picture and I'm trying to use it to power those tiny wireless LEDs (also on the picture)
The components work properly, as the charger can charge my ...
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Excluding silk-to-silk rules for connected text and lines
This question is quite specific so I thought that I'd give it a shot.
On my top overlay layer I have text and lines which looks similar to the video
Phil's Lab #84 which can be seen at the timestamp ...
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RFID antenna and LoRa module/flex antenna on the same PCB
I need to place LoRa module on the PCB I designed. There is already an RFID antenna on this PCB that I designed before, and it is not possible to change its location.
Is the distance between LoRa ...
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What is the purpose of these Schottky barrier diodes connected with reverse polarity between the Vin line and gnd?
On the laptop's PCB I see two Schottky barrier diodes connected with reverse polarity between the Vin line and gnd. What is the purpose of this?
At first I suspected that it might be a TVS or a Zener ...
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Does measuring current with a multimeter in series affect battery life?
I have noticed that a lower-power device that I am testing is running out of power much sooner than it should. The device should last up to 2 years, however, it is running out of battery at the 5-...
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Is it possible to make all components pads NPTH in Eagle for a multilayer PCB?
Using Eagle for a two sided PCB design.
One requirement is that all components pads to be non plated through holes (NPTH) and vias are to be PTH before starting autoroute.
Can someone tell me how to ...
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What is the difference between these vias?
I have marked them with red and purple. What purpose do they serve?
P.S. I am new to this, so please help me through this.
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Deliver high current through vias
There is a demand for a delivery of 3 A through several layers using vias.
Presented below in the picture is my PCB manufacturer's abilities regarding vias.
A single via can withstand 1.4 A. Are there ...
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Kicad: Create Symbol and Footprint for SoM
I am designing a PCB containing the UCM-iMX8M-Plus system on module. This module connects to the PCB using two DF40HC(3.0)-100DS-0.4V(51) connectors.
I would like to create a symbol and a footprint ...
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Power management for components on a PCB
I’m a begineer in PCB designing and I'm designing a circuit where I have 4 ICs connected in parallel. I have used JW5068A IC which have output voltage of 5 V and max current of 8 A for whole circuit.
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Soldermask clearance on micro USB connector
I'm designing a board in Altium which uses a micro USB connector however the footprint is giving me some trouble with the DRC.
As seen above the pads are relatively close which causes these tiny ...
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Tight GND plane Pros and Cons
Imagine a typical 2Oz/1Oz, 4 layer PCB with a stack-up, Sig/Pwr, GND, GND, Sig/Pwr. Your typical trace width/space would be 0.2mm/0.2mm, and a prepreg Dk of ~4, ignore the Core. Fastest signal on the ...
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Avoid ground loop for multiboard high-current device
Problem overview
I am designing a multi-board pulser device for ultrasound, and am encountering a conceptual issue when trying to prevent a ground loop in this device. I added a minimal example to ...
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Right-angle traces vs curvilinear traces in a PCB
In a PCB, what is the advantage of using curvilinear copper traces compared to right-angle traces? Can there be a difference in heat dissipation in a right-angle trace that has 270° of free space at ...
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