Connect with us

EMC good practices

Discussion in 'General Electronics Discussion' started by Rajinder, Feb 6, 2018.

Scroll to continue with content
  1. Rajinder

    Rajinder

    538
    10
    Jan 30, 2016
    Hi
    I was wondering if someone could help me with the following EMC and PCB layout questions:

    1. Why is it good to have a separate layer dedicated to the GND? Is it because it is a low inductance/resistance path to ground? i.e. less voltage spikes?
    2. Are track lines meant to be short as possible because the longer the track the more it radiates as a antenna?
    3. If I had a 30mm track, what would I need to change for a 1MHz square wave compared to a 5GHz square wave on the same length of track? What modifications would I need to make?
    4. I am not sure what ground current loops are and how to reduce the effects of these.
    5. When choosing a decoupling capacitor say for example a 100nF on a IC (between VCC and 0V) close to the IC pins. Do I use Xc = 1/(2*PI*F*C) as the formula? For the frequency (is that the frequency of the signal I am looking to reduce?) Also should I aim for a value of XC to be as low as possible but not 0, as 0 would be a short between VCC and 0V?
    6. Why is it a good idea to have the VCC and GND layers (on a 4 layer PCB), back to back?

    Thanks in advance
     
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    12,340
    2,931
    Nov 17, 2011
    People have answered this question so many times on the internet.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-