Common-mode signal: Difference between revisions

Revision as of 17:10, 7 June 2023

Revision as of 17:27, 7 June 2023

Line 18:

* A [[transformer]], which is useful for AC signals only, and will filter any form of common-mode noise, but may be used in combination with a bifilar wound coil to eliminate [[capacitive coupling]] of higher frequency common-mode signals across the transformer. Used in twisted pair Ethernet.<ref>{{Cite web |url=http://pulseeng.com/products/datasheets/H325.pdf |title=Archived copy |access-date=2013-12-17 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304000938/http://pulseeng.com/products/datasheets/H325.pdf |url-status=dead }}</ref>

Common-mode [[Filter (signal processing)|filtering]] may also be used to prevent egress of noise for electromagnetic compatibility purposes.:

* High frequency common-mode signals, for example(e.g., [[Radio frequency|RF]] noise from a computing circuit,) may be blocked using a [[ferrite bead]] clamped to the outside of a cable. These are often observable on laptop computer power supplies near the jack socket, and good quality mouse or printer [[USB cable|USB cables]] and [[HDMI cables]].<ref>{{Cite web |url=http://www.elmac.co.uk/pdfs/ferrite.pdf |title=Archived copy |access-date=2013-05-07 |archive-url=https://web.archive.org/web/20120706223753/http://www.elmac.co.uk/pdfs/ferrite.pdf |archive-date=2012-07-06 |url-status=dead }}</ref>

* [[Switched-mode power supply|Switch mode power supplies]] include common and differential mode filtering inductors to block the switching signal noise returning into mains wiring.<ref>http://www.hottconsultants.com/pdf_files/APEC-2002.pdf {{Bare URL PDF|date=March 2022}}</ref>

[[Common-mode rejection ratio]] is a measure of how well a circuit eliminates common-mode interference.