Parasitic Oscillations and EMI Emissions
Parasitic oscillations are one of the four typical causes for emissions in EMI/EMC problems. Try to reduce the gain or break the feedback and the problem could be solved at low cost.
Ringing with High Quality Components
Many EMI and SI problems are related with a combination of inductance and capacitance without losses.
Evaluate Shielding Effectiveness With Your VNA
The effectiveness of different materials for shielding can be tested using near field probes and your vector network analyzer (VNA).
How High Frequency Filter Response Can Be Destroyed
If your EMI filter is failing in high frequencies, check the frequency response of the components: parasitics limit the filtering effectiveness.
Using Capacitors in Parallel: Dangerous?
For many applications, especially in digital designs, you can see decoupling networks composed of several different (big and small) capacitors in parallel. But, sometimes this technique can be dangerous.
To Avoid Problems, Work as Slow as Possible
You can minimize your EMI/EMC and SI/PI problems by working as slow as possible. This is very well known advice from many experts, books, and seminars: you can minimize or solve electromagnetic interference (emissions/susceptibility) and signal or power integrity problems working as slow as possible.
Use The Eye Diagram to Check Your Connections
Discover the eye diagram, a very useful visual tool to analyze the quality of your connections in digital and high frequency applications.
Ferrites to Kill Ringing or Not?
Sometimes a ferrite is used to remove ringing in some applications as in power electronics or digital circuits.
Orientation Is Relevant For EMI/EMC Filters
When designing an EMI/EMC filter the orientation relative to source and victim is critical for high effectiveness. Can you save components in your filters?
EMI Debugging: If You Can See It, You Can Fix It
If you are a novice designer of electronic circuits, this is one of the best pieces of advice I can give you from my experience in EMI troubleshooting and training.