Can Replacing Chip EMI Filter Capacitors Improve Attenuation Characteristics?

  • Thread starter Thread starter stepa
  • Start date Start date
  • Tags Tags
    Emi Filter
Click For Summary

Discussion Overview

The discussion centers on the potential impact of replacing chip EMI filter capacitors on attenuation characteristics. Participants explore the implications of changing capacitor vendors and tolerances, focusing on the technical aspects of filter design and performance.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that replacing a capacitor with a different tolerance could improve attenuation characteristics due to the possibility of achieving a higher capacitance value.
  • Another participant requests additional information about the filter topology and the specific tolerances being referenced, indicating that multiple factors contribute to filter performance.
  • A participant identifies the specific capacitor models being discussed and provides links to their datasheets.
  • One participant concludes that the replacement capacitor should perform as well or better than the original, but notes that the overall filter characteristics will depend on other components in the circuit.

Areas of Agreement / Disagreement

There is no clear consensus on the impact of the replacement capacitor, as participants express differing views on the importance of filter topology and other components in determining performance.

Contextual Notes

Participants have not fully explored the implications of the filter topology or the interactions between components, which may affect the overall performance of the EMI filter.

stepa
Messages
4
Reaction score
0
I have some chip emi filter capacitor type. Its parameters are size 0603 , 1000pF , tollerance +/-20%. I would like to replace it by filter of another vendor, with the difference of tollerance -20/+50%.
As I'm understanding from attenuation characteristics chart, the replacement maybe even better, cause for +50% tollerance I will have a chance to get higher capacitance value and higher insertion loss.

Is it correct?

Thanks
 

Attachments

  • untitled.JPG
    untitled.JPG
    65.3 KB · Views: 461
Engineering news on Phys.org
Can you post a link to the datasheets? It takes more than a capacitor to make a filter -- what is the topology of the filter? A "T" or a "Pi" maybe? What is this tolerance on? Just the capacitor, or something else about the filter?
 
One of them is Murata, NFM18 series: http://search.murata.co.jp/Ceramy/CatalogAction.do?sHinnm=?&nbsp&sNHinnm=NFM18CC102R1C3&sNhin_key=NFM18CC102R1C3B&sLang=en&sParam=nfm18
And the 2nd is SMI, SGM16-2A series:
http://www.smied.co.jp/smi_english/product/noise2006.pdf
 
Last edited by a moderator:
Hmmm. So these are 3-terminal feed-through capacitors, with low/negligible series inductance. So to answer your original question, yes, the 2nd part should do as well or better than the muRata Erie part.

The filter characteristic will depend on what other components you place in series with the feed-through capacitor.
 
Thanks a lot.
 

Similar threads

  • · Replies 21 ·
Replies
21
Views
13K
Replies
17
Views
6K
Replies
6
Views
5K
Replies
2
Views
4K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 9 ·
Replies
9
Views
4K