Questions tagged [pcb-design]

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.

Filter by
Sorted by
Tagged with
0
votes
1answer
33 views

Convert High voltage output ( 15V ) to 5 V

I want to use : DSD 70 Dual Channel Hall Effect Speed Sensor and integrate it with an MCU ( arduino ) atmega , so I have to convert the output of the sensor to 5V to be able to read it by the MCU. Any ...
0
votes
0answers
13 views

Creating a converter between 2 types of FFC cable

I will try to make this question as specific as possible, but as I have never done something like this before, I might not be able to do it perfectly. My current situation is the following: I have a ...
0
votes
2answers
93 views

Why are most of the RESET signals in embedded systems active low?

I am hardware design engineer. I had seen lot of board designs since 2015. In my career I have seen that most of the RESET signals are of active low signals. Is there any logical reason behind that? ...
0
votes
1answer
42 views

How to fix and avoid micro USB connection issues?

Some of my smartphones / tablets developed after some years problems with their micro USB connectivity. E. g.: Motorola Moto E 2nd Generation Nexus 7 2013 Samsung S3 A connection could only be ...
0
votes
2answers
67 views

Shifting Op-Amp value

Have a design that is taking an input from .549V-.838V out of a DAC and am trying to get it to amplify it into a range that would be more useful in an ADC, like 0-5V. So far I came up with this ...
0
votes
0answers
19 views

How to create/optimize a matching circuit in the middle of a PCB with a network analyzer?

I have a PCB with an SMA connector as only input. The block diagram of the circuit looks like: I would like to update the L-match for optimum matching (L, C1, C2 at 915 MHz). I connect a VNA to the ...
0
votes
3answers
563 views

What are these arrows on a schematic?

I am trying to understand a schematic by Espressif for the ESP32 devkit v4. There are 7 arrows on U1 (CP2102N-A01-GQFN28) and 1 on U3 (ESP32_WROVER(NC)). Why U1 have a green rectangle? Link to the ...
4
votes
1answer
32 views

EAGLE - set part to a different layer without mirroring it

I need to set a new layer for a part without actually mirroring it. I have many pin headers already set up on my board and wired up, but I need some of them to face the other way (Set them to bottom ...
0
votes
2answers
38 views

Editing/Creating a Triangular Solder Bridge Footprint

I wish to use a triangular solder jumper (solder-jumper) in my PCB and I am using KiCAD. The only available solder jumper - the one pointing in one direction (as in the attached image), is 2.45 x 1.50 ...
0
votes
1answer
60 views

ESP32-PICO-D4 can it work raw?

Can this system in package be used raw without any other components(resistors,capacitors,inductors,crystal etc)? If I create a test board with holes for every pin to test it with arduino ide would it ...
1
vote
0answers
35 views

Are there any generally acceptable UART best practices when it comes to hardware design

Are there any generally acceptable UART best practices when it comes to hardware. Hi, I am trying to design a PCB that uses UART to communicate between two microcontrollers. Are there any generally ...
0
votes
1answer
63 views

How to distribute power to multiple devices on a PCB

I am new to hobby level PCB's, but looking at taking my projects to the next step moving from breadboard. The part I do not know how to do, or see on tutorials is how do I take a single 5V line (or ...
0
votes
2answers
82 views

How to determine current flow direction in a circuit?

I have this diagram: The datasheet specifies I should bias the COMM+ line around 1.5V. However, when I measure the voltage at TP1 with the oscilloscope probe connected to ground, the output from the ...
0
votes
0answers
39 views

Problem with CH340C

Hi I made a board that contains an ESP32-WROVER and an USB to serial adapter ch340c but it's not visible when I connect it to the PC (Windows 10). I tried to install the ch340 driver and I even tried ...
2
votes
0answers
43 views

Wires under diodes on a PCB: distancer, radiator, ground return loop, or something else?

I recently watched a video by bigclivedotcom and there's one unusal (at least for me) thing on the PCB he presented. That's a switched power supply for a flat TV panel: Under three parallel power ...
1
vote
2answers
100 views

First SMD Design Comments / Input before Manufacture

Just designed my first "real" PCB that I plan to send out for manufacture in the next day or so. I've milled out a few on a 3018 CNC. I wanted to do this one that way as well, but realized ...
1
vote
1answer
63 views

Can similar inductor value be used?

I found a schematic online of a 433mhz receiver which I am trying to replicate. 1 component is an inductor 16.6nh smd. However because I cannot find that exact value I was thinking to use an inductor ...
1
vote
2answers
43 views

nRF24 PCB Antenna Choices

I am trying to create RF module using the nRF24L01P. I am trying to maximize the range while still using a trace antenna. My plan is to combine the simple trace antenna design with the long range ...
2
votes
0answers
48 views

ATmega328P development board not working

I've made a development board for ATmega328P like Arduino Uno. Fig. 1 - schematic Fig. 2 - bottom layer Fig. 3 - top layer I am able to upload the code using FTDI chip (I've used the chip which ...
2
votes
0answers
37 views

Multi-layer Via-in-pad with 0.5mm Pitch BGA in KiCad

I am working on a 4 layer board with an 81 pin 0.5mm pitch BGA which effectively requires via-in-pad for dropping down to other layers. Decoupling must be done on the bottom as there is no space for ...
0
votes
0answers
53 views

CN3722 solar charging IC not working properly

I'm currently working on a custom PCB where I have a microcontroller hooked up to 3 LiIon batteries which are meant to get charged by a CN3722 IC. However, when I connect a solar panel to the circuit ...
-1
votes
1answer
71 views

About smd capacitors values and voltage rating [closed]

My Dell 3542 (2014)laptopboard got failed...i tested the board,and i found 4 smd capacitors have fialure...there is no any thing on the board to inform me about the value or voltage rating of them ...
0
votes
2answers
100 views

Is there a downside of using PCB printed USB connector?

Typical USB Type A receptacle is as shown in this image from Molex 48037-1000, which can be mounted on PCB. I have seen some products with USB connectors printed directly on the PCB edge like this ...
1
vote
1answer
47 views

Hole to trace clearance determination

I am using M3 screws on a PCB, I need to know the considerations needed to specify the minimum clearance between screw hole and traces.
0
votes
0answers
17 views

Ferrite underlay impact on chip antenna performance

I'm designing a small wireless chargeable IoT device which also has TX/RX in subGhz frequency (LoRa). The idea is to stack everything on top of each other starting with charger RX coil, then ferrite ...
0
votes
1answer
60 views

how to design step groove pcb in altium designer

I need to design a multilayer pcb in altium designer that has cutout just in one layer. I was seeking that and I found out that in china it is called 阶梯槽. I translated to English but I didn't find any ...
2
votes
2answers
237 views

Which design produces least EMI?

Inspired by the idea to minimize the return path, I am thinking about the two possible improvements of the design, how to connect the signal source to consumer. In short, there are lots of high ...
1
vote
0answers
18 views

Custom HDMI-to-( TFT or LVDS ) decoder/driver

I am working on a custom-made handheld PCB based around a PI Compute Module 3+ and one of the hardest steps I have found is how to include an HDMI-to-50pin-TTL driver on my PCB to run an LCD TFT 7&...
1
vote
1answer
37 views

Calculating maximum permissible track amperage for intrinsic safe PCB

I'm reading IEC 60079-11 standard (Equipment protection by intrinsic safety "i") which discusses how to design intrinsic safe circuit boards. In section 5.6.4 it talks about permissible ...
0
votes
1answer
26 views

Contact ESD protection vs Air gap ESD protection

There many ESD diodes available in market for ESD protection from connectors or 'touch surfaces' of product. But how about air gap ESD attack? What if I have large PCB with connectors at the end, ESD ...
0
votes
4answers
93 views

Joining two different-widths PCB traces

I need two join two traces of different widths, I use two different width at first place due to space constrains at some parts of the board. so what is the best method to do it elegantly and with no ...
0
votes
1answer
38 views

Inductor value for power supply design

I am designing a power supply card using V7805-2000 for 12V to 5V conversion. In the datasheet on page number 6 they have a recommended input filter and output filter circuit. For the inductor they ...
0
votes
0answers
31 views

Incorporating Additional Devices in Custom PCB

I've been tasked with designing a custom PCB based on a prototype I made this past year. This prototype uses ST's NUCLEO-F030R8T6 development board along with some stepper motor drivers (AMIS-30543) ...
1
vote
1answer
38 views

Supplying NTC by different voltage from VCC

I would like the sense a material temperature that is located outside of panel. My NTC thermistor is 10meter far from my STM32 MCU based control board. I don't want to use VCC at outside of the panel ...
5
votes
4answers
2k views

Why do some PCBs have these circular rings? Are they plated through hole vias?

Do they serve any mechanical purpose? Also, there are eight dots on these rings.
0
votes
2answers
31 views

PLL Layout guidelines

I am designing a custom board using HMC833LP6GE. I am taking schematic reference from the Evaluation module. There will be onboard DS-PIC MCU for controlling the PLL. The reference input can be fed ...
0
votes
2answers
94 views

H-Brdige MOSFETs getting hot despite no load

I'm building a 600v H-Bridge using IPZA60R060 MOSFETs together with isolated gate drivers UCC21520. I designed the PCB layout to be as tight as possible and thought I'd done a good job routing the ...
20
votes
6answers
5k views

Why would a circuit designer use parallel resistors?

I've been reviewing this reverse engineered schematic of a bmax6 style lipo charger. To my understanding this circuit is used to dissipate excess charge in a cell when balance charging. The circuit ...
2
votes
0answers
29 views

Far field simulation results

I am trying to study the radiated and conducted EMI fields of my PCB using ANSYS SIwave. I did the DC IR drop analysis, and that was okay. Next I did the "Compute Near-field" and "...
1
vote
0answers
41 views

What is the minimum clearance I need to set between two tracks with voltage difference 36 V

What is the minimum clearance I need to set between two tracks with voltage difference of 36 V. External traces, given that solder mask is applied on the board if it matter in calculation. And is ...
0
votes
1answer
29 views

Difference between EMI filter and RFI filter

I always see EMI filters on power entereing of machines. They have generally circuit something like a below: The machine that I investigad has noise limitter filter that called RFI filters on ...
6
votes
2answers
167 views

Ground loops in a PCB with large hole in the middle

I'm designing a board for a client with some unusual constraints. My question is well illustrated with the following simplified example. Assume the positions of everything are fixed. Let's also ...
0
votes
1answer
84 views

Boost converter PCB layout

I am working on the hardware of a boost converter which I will cascade with a buck converter. I will just pose a question on my boost converter since I assume the same knowledge can be applied to my ...
2
votes
1answer
38 views

Can't program ATmega with ICSP on custom pcb

I'm fairly new to PCB design, and I've been trying to program the microcontrollers on the board I designed with no luck. The board uses an ATmega32u4 and an ATmega328P. I've been trying to program ...
0
votes
0answers
22 views

Reducing Thermal Pad Size Below Official Footprint - Can It Create Manufacturability Problems?

I'm using a DP83867 Ethernet chip by Texas Instruments in an S-PQFP-G64, 10 x 10 mm package, the mechanical dimension and its recommended footprint are shown at the end of the question. As shown, the ...
0
votes
0answers
60 views

Would a SIGNAL - GND - SIGNAL - 3.3v PCB stack okay?

The Typical 4 layer PCB stack up would be Primary Signal GND Vcc Secondary signal And i have always used this on my 4 layer projects. On this current project however the Back side of the PCB is ...
2
votes
1answer
70 views

Basics of board level shielding and grounding

I have been designing MCU based PCB that must be withstand hard EMI tests. This PCB includes ethernet transceivers, can transceivers, rs485 transceivers, II2 chips, 25MHZ oscillators, optoisolators ...
0
votes
0answers
54 views

Overkill battery charging circuit?

I want some experience in designing electronic circuits, and have chosen to build a battery charging circuit for a possible future PCB. I've tried to follow all the advice I can find online about ...
1
vote
3answers
88 views

Placement of decoupling capacitors when driving a load through a long cable?

Common knowledge is that decoupling capacitors have to be close to the device that's being decoupled and connected with as short as possible connections, to provide a low inductance path. Does this ...
0
votes
0answers
16 views

How to select the setup time and Hold time for the DDR3/4 SI analysis?

I am performing SI EYE analysis for the DDR3 interface. Following are my consideration for the DDR3 SI analysis:- Data rate= 800MHz/ 1600 MT/s Data UI = 0.625ns = 1/800MHz Address, command and control ...

1
2 3 4 5
55