Selecting Common Mode Filter Chokes for High Speed Data Interfaces

High speed data interfaces like USB, HDBaseT™, HDMI, DVI, and DisplayPort require careful consideration to ensure reliable communication that is free of disruptive EMI. Of the many tools at the designer’s disposal like trace routing, termination and component placement, the common mode filter choke remains one of the most powerful. This application note discusses the benefits of using common mode chokes and reviews the performance characteristics associated with their proper application

Common Mode Filter Design Guide

The selection of component values for common mode filters need not be a difficult and confusing process. The use of standard filter alignments can be utilized to achieve a relatively simple and straightforward design process, though such alignments may readily be modified to utilize pre-defined component values.

How EMI Filters Are Specified For RF Performance

Don’t overlook the fact that EMI filters can be used to prevent unwanted RF noise (such as electrical fast transient burst, conducted RF, and some surges) from entering susceptible devices.

Fast Evaluation of a Filter or Shield Against an Electromagnetic Pulse

Single electromagnetic pulses like lightning, ESD, powerline transients, NEMP, etc., are generally described in time domain, while filters and shields are practically always characterized in frequency domain. This article describes a quick and handy formula and nomogram providing a fair estimate of the filter or shield response to a conducted or radiated threat.

Let’s Talk About Why Filters Fail

This article looks at some of the reasons why the filters you may think will work often do not when they’re put into real circuits. So… let’s talk about why filters fail.
article placeholder

S-parameters and EMI Filter Response

S-parameters are very useful to evaluate, understand, and optimize the response of your filters. If you are unfamiliar with this typical tool for RF engineers, this column is for you.