EMI Filters / RFI Filters are passive components that work to suppress electromagnetic interference/radio frequency interference within signals. This process is also known as EMI Suppression. EMI Filters work in applications like appliances, electronic devices, power lines, etc. to lessen high frequency electromagnetic noise.  

At TTI, we carry a wide selection of EMI Filters / EMI Suppression types, such as EMI Feedthrough Filters, EMI Gaskets / Sheets / Absorbers / Shielding, Ferrite Beads. You can browse TTI to find the right EMI Filters / EMI Suppression for your electronic design. We stock high-quality electronic components from trusted manufacturers like EPCOS / TDK, KEMET, Knowles, Laird, Murata, Tusonix / CTS and more. 

As technology continues to advance, the operating frequencies of devices are also tending to get faster as well. This results in an increased amount of electromagnetic interference (EMI) that must be dealt with by engineers  in order to keep their products in compliance with current regulations by independent agencies such as UL, CSA, CISPR, FCC and IEC. Depending on the application and market segment that a product is intended for, there will be different thresholds for the acceptable amounts of “noise” that a given device will need to be immune from as well as radiate. EMI can be man-made or natural, but regardless of the source, it can cause an undesirable response, malfunctioning or degradation in the performance of electrical equipment. This is where steps must be taken to mitigate or attenuate these unwanted noise signals by implementing a variety of filtering techniques and components. Although a good PCB layout is the best way to steer mostly clear of EMI, this is not always entirely possible considering other variables such as limitations on available space, cost and even time. Additionally, engineers can utilize a variety of shielding, grounding, and isolation techniques to work around limitations such as this. 

Capacitive filters, inductors, and ferrites are three common components that will help with EMI filtering, depending on the frequency that needs to be suppressed and the amount of suppression needed. Also, combinations of inductors and capacitors (in series and parallel) provide the basic structure for filtering circuits such as LC, Pi, and T filters. While capacitive filters conduct unwanted noise signals to ground, ferrite beads accumulate this energy in the core and dissipate it as heat. SMT ferrite beads for example, can be effective measures for attenuating noise on both power supply and data lines, however, they are limited in terms of the amount of impedance they can provide. For applications where higher levels of impedance are required, inductors (such as common-mode chokes, line filters, etc.) can be used. For example, EMI filter inductors/toroidal common-mode chokes are typically seen on the input/primary side of an AC/DC power supply.

Regardless of the type of EMI suppression that is needed, TTI’s broad and deep inventory of inductors, filtering capacitors, EMI suppression sheets, and ferrites will have you covered. Our top-notch suppliers are offering AEC-Q200 qualified and high-reliability components to suit your applications for military/aerospace, automotive, and consumer products. Whether you are in the beginning stages of a new design or late in the game and trying to bring your product to market immediately, let TTI be the answer.