Electromagnetic interference (EMI) is unintended harmonic energy from changes in voltage and current that can degrade signal integrity and damage components. EMI filters reduce this unwanted energy at the power entry point to meet international standards and are predominantly designed with passive components for broad frequency filtering. Premier Filters offers a range of EMI power line filters for various applications, along with custom design capabilities.

1. Before EMI Filters, let’s know about what is EMI. Electromagnetic interference (EMI) is mainly defined as
the unintended harmonic energy that is generated by sharp changes in circuit voltage and current (dv/dt
and di/dt). Primary sources include power conversion and logic circuits. This energy can propagate into
and within equipment degrading the integrity of a signal or possibly damaging components, thus
affecting the equipment’s overall functionality.
An EMI Filter is a device that is installed at the power entry point of equipment to reduce unintended
harmonic energy below circuit operational levels, as well as to meet commercial and military
international EMI standards. These standards are established and regulated by the FCC, EN/CE and
various Government/Military agencies. The main frequencies of concern governing power line
conducted emissions are 10KHz to 10MHz for Military environments and 150KHz to 30MHz for
commercial/industrial applications. From a design perspective, EMI filters can consist of both passive
and active components. However, due to their ability to filter over a broad frequency range, passive
designs utilizing inductive and capacitive elements comprise the majority of EMI filter products in the
market.
The primary operation of EMI/RFI filters is to provide varying impedances over frequency in opposition
to equipment circuit impedances. As EMI filters deal primarily with unintended, high-frequency
harmonic noise their function is reflective. Primarily, the EMI/RFI Filter circuit is designed so that
externally or internally generated noise is reflected back to its source. Although it is not technically an
EMI application, these are often specified for line harmonic filtering. In this application, the filter’s
inductive components must be designed to provide wave shaping of the AC line without saturating.
Unlike typical EMI Filter, which primarily utilizes common-mode inductive elements that are resistant to
line current saturation?
At Premier Filters, we offer an extensive line of standard EMI Power Line Filters for all AC and DC
applications, including commercial, industrial, military, tempest, and facility/SCIF. Our standard offerings
are complemented by an almost infinite custom capability with designs of 5K volts and 3k amps.
Contact Us
ADDRESS: Premier Filters, Inc. 952 N. Elm Street Orange, CA 92867
Phone: +1 (657) 226-0091
FAX: +1 (714) 602-6096

2. Email: info@premieremc.com
Website: https://www.premieremc.com/emi-rfi-filters/