# Questions tagged [trace]

Lanes of copper on a printed circuit board, for carrying current or signals between pads

168 questions
Filter by
Sorted by
Tagged with
974 views

### What should be considered when sizing trace widths for digital logic signals?

For traces that carry a static DC current, it's pretty easy to calculate the minimum trace width based on the required ampacity of the trace. However, I'm not sure what should be considered when ...
2k 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 ...
409 views

### 11A trace width

Using this PCB Trace Width Calculator the external tace width for 11A (default settings) is suggested as 8.21mm. Is this acceptable? I was expecting something bigger, and just wanted to check that ...
2k views

### In Altium how do you increase the trace width from a Pour to GND Vias and Pads?

In my PCB layout I have a ground power connector and several pads where I would like thick traces to connect to the ground plane. When I use the polygon pour feature, it will connect these with 4 ...
24k views

### How to calculate parasitic capacitance in a trace?

I am given the equation for parasitic-capacitance as: $C = \dfrac{\epsilon_r \cdot \epsilon_0 \cdot L \cdot W }{ d }$ I am also told my trace is to be 1000 micrometers long (1mm) and 45nm wide. ...
59k views

### How to make traces on an universal PCB?

I hope this question won't be closed as too subjective. I'd like to know best practice - how to make traces on universal PCB's with individual holes without traces (like the following image). My idea ...
275 views

### SDRAM on opposite side of board with respect to uC

Just a quick question. Is it advised against to place a high speed memory device on the opposite side of the PCB with respect to the microcontroller? And if it is ill advised, how is it possible to ...
2k views

### Why Altium routes trace to the side of the pad?

I am curious, are there any reasons why Altium tends to route a trace to the side of a pad, instead of the top? The top looks more logical, since it will not disturb other traces in a SOIC for example....
923 views

### Trace width to 0805 pad?

How worried should I be if I route wider than 10 mil trace to 0805 pad? Would 16, 20 or 24 mil trace cause soldering problems without making 10 mil neck?
722 views

### Satisfactory Margin for Traces from PCB Edge

I've had problems routing too close to the edge of a PCB before and was wondering if there's a suitable rule-of-thumb that I should use (maybe to put in a design rule in Altium somehow with my keepout)...
1k views

### How do you adjust the trace rotation on a Hameg HM 307?

I have a [rather old] Hameg HM 307 oscilloscope with the trace rotation slightly off. There is no trace rotation adjuster anywhere on the outside of the device. The user manual mentions that it is ...
3k views

### Repairing broken trace on commercial board

A friend has a USB flash drive on which the SMD USB connector broke off. When it broke, it pulled the pad traces off the board with the solder. We are trying to think of a way to reconnect the ...
4k views

### How to measure propagation velocity through a trace on a pcb?

With a pcb in hand, how to measure the propagation velocity of a path from point A to point B, with accuracy in the picoseconds range?
305 views

### Unoccupied SMD and TH pads and noise/interference/capacitance

Imagine a rather noise sensetive application, My question is if there are unoccopied pads for SMD and through-hole are existing on the board and somehow connected to other components through theire ...
2k views

### How to calculate typical signal trace clearance?

Knowing nothing more than most of the signal traces on a project are 7.5mil and it's a high end audio product, i.e. it's not a high frequency or any 'advanced' application, what would be a safe ...
3k views

### Eagle Schematic and Board layout design for simple opamp module questions

Hopefully I'm not doing anything illegal, I posted a very similar question a few days ago, but this one is different. Here is what I've been working on the past couple days, trying out different ...