Radio Frequency (RF) & Wireless Design

Created by Steven Minichiello on 27 April, 2018

Common Mode Power Line Chokes (ET20H, UT20V) from Wurth Electronics

Recently I had to add some power supply EMI line filtering on the front end of the power supply to reject conducted line noise and the best way to do this is with a common mode choke : https://en.wikipedia.org/wiki/Choke_(electronics)


There are (2) types of chokes :


Full Wave and Bridge Rectifiers help eliminate differential mode noise, but common mode noise is better handled with a common mode choke.


I have posted these two common mode chokes from Wurth Electronics.


The Wurth ET20H series if used for lower profiles (horizontal) configurations where space is not an issue, but height may be :




The Wurth UT20V series if used for higher profiles (vertical) configurations where space is an issue, but height is not :



Electrical characteristics are similar for both configurations and both are limited to 2.65 Amps with a maximum of 43 milliHenries of Inductance at the lowest current version of 0.4 Amps.