EMI filters with ESD integrated protection

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What is the purpose of an EMI filter?

Targeting low-speed digital interfaces for analog applications, ST’s EMI low-pass filters protect datalines in memory cards, USB low-speed or full-speed interfaces, microphones, speakers and displays against ESD surges and help remove EMI noise to ensure compliance with EU directive 2014/30/EU and technical standards EN 55032 / CISPR 32 (Electromagnetic compatibility of multimedia equipment -Emission Requirements) and EN 55035 / CISPR 35 (Electromagnetic compatibility of multimedia equipment -Immunity requirements).

Depending on the application to be protected, they feature a low-pass filter combined with ESD protection diodes and pull-up and/or pull-down resistors.

Benefits of ST’s EMI filters

Thanks to ST EMI filter integration level, electronic system designers can save PCB space compared to equivalent discrete solutions while hardening their application against electrostatic discharges and EMI noise.

Another benefit is the wider frequency range rejection thanks to a lower parasitic inductance compared with discrete solutions. This provides design flexibility when designer needs to modify slightly the PCB layout as the resonant frequency of the filter will not be modified unlike in discrete solutions.

Our EMI filters feature R-C (for first order) or L-C (for second order) passive Pi filters.