What Are Power Line Filter Modules and Why Do You Need Them?

Line filters are components designed to suppress conducted EMI on power and signal lines. They prevent noise generated within a device from escaping into the power network, and just as importantly, block external interference from entering sensitive electronics. Without proper filtering, EMI can lead to data corruption, system malfunctions, premature component failure, or failure to meet global EMC standards.

TE Connectivity offers a broad portfolio of single‑phase, three‑phase (Delta) or three-phase (Wye), and DC line filters, engineered to handle a wide range of voltages, currents, and environmental conditions. These filtering solutions help ensure signal integrity and long-term reliability. The difference between Delta and Wye is the wires.  Delta has 3 wires – without neutral and Wye has 4 wires with the neutral line for common mode filters or single-phase loads.

Some examples of TE Connectivity Corcom’s inline power filters. (Image source: TE Connectivity Corcom)

Once you know the “phase”, you can then pick single, two, or three stage configuration on DigiKey’s Website. What is the difference between phase and state, you ask?  It all relates to whether you are focusing on the signal’s timing/distortion (phase) or the filter’s operating mode/behavior (state).

• Phase refers to the time shift or delay different frequencies experience through the filter, affecting transient response and wave shape. Pick this if you are concerned with time-domain distortion.
• State (often seen as "State Variable Filter") refers to the operational mode of the filter, such as simultaneously providing low-pass, band-pass, and high-pass outputs. Pick this one if you need functional versatility, such as classic analog sound quality.

TE Connectivity understands that not all applications are the same, and that is why their line filter offering covers a wide range of products from Corcom to Schaffner products. Schaffner was acquired by TE Connectivity in 2023 to broaden their footprint. This acquisition leveraged their combined strengths across the entire portfolio for their customers. (Source: Schaffner | Now part of TE Connectivity | TE Connectivity).

Commonly Power Line Filters are used in a variety of industries and applications, including:

• Industrial automation and motor drives
• Medical imaging and diagnostic equipment
• Data centers and networking infrastructure
• Aerospace and defense electronics
• Renewable energy and power conversion systems

TE designs line filters that integrate seamlessly into modern electronic systems. Their solutions are developed with system‑level performance in mind, helping engineers reduce EMI at the source rather than relying on secondary fixes downstream.

Table 1 makes it easier to find your best fit solution, just click on any family/series to go right to DigiKey’s website. This represents just a snapshot of the more than 3,000 part number solutions offered by TE Connectivity. If there is something you need that is not on the list, please click this LINK to see the entire product offering.

Table 1: Highlights of filters suitable for various performance needs. (Source: Kathy Hutton)

Summary

EMI control is essential in today’s noise-sensitive electronic environments. TE Connectivity’s line filters provide that proven, reliable way to protect system performance, ensure compliance and simplified design challenges. DigiKey helps you find the right filter to help you build cleaner, quieter, and more dependable electronics from Prototype to Production.

Additional Information

FN3297/FN3298 Series Three-Phase+N Filters

FN2640/FN2660 Single-Phase Low-Profile EMC/EMI Filters

FN222/FN223/FN224 Series DC-Busbar EMC/RFI Filter

FN3025/FN3026 Three-Phase Compact Lightweight Filters

FN2500 / FN2520 Single Phase EMC/EMI Filters

FN2410(H)/FN2412(H) Line Filters

FN3258 Series 3-Phase Filters

EMI/EMC Filtering Solutions for Medical Electronics

Have You Considered Everything in the Design of Your EMI Filter