FN9255 Series RFI Filters with IEC Inlet C14 or C2

By Schaffner EMC Inc 235

FN9255 Series RFI Filters with IEC Inlet C14 or C2

The FN9255 series of RFI filters with IEC inlet C14 or C20 is Schaffner's first inlet defined up to 300 MHz. The dual-stage high-performance FN9255 filter series is an addition to the market-proven FN92xx filter families and is developed for high-frequency applications, even above 30 MHz.

The adaption of the filter housing is done in length only, which means the FN9222, FN9233, FN9244, and FN9255 will fit in the same cutout, allowing to exchange one for another if the performance is not enough with one of the basic models.

The high number of variants includes about 100 different filter types. Amongst those one can find two versions designed for medical applications; one with and one without earth line choke.

The series also features a rear mount version, which includes a press-in nut to allow a reliable assembly without adding up to the chassis of the system.

With variant diversity and the present attenuation properties, FN9255 offers a solution for modern appliances for household, audio, video, and medical devices. They can also be used in several other applications with similar requirements.

The filters have all the required safety approvals (UL 60939-3, IEC 60939-3, and CQC), are marked according to CE, and are compatible with the RoHS II (2015/863) directive.


  • Exceptional attenuation performance from 150 kHz to 300 MHz due to dual-stage design
  • High saturation resistance and excellent thermal behavior
  • Rear and front flange or snap-in mounting options
  • Optional medical versions (B type) comply with the requirements of IEC/EN 60601-1 for creepage and clearance, leakage current and high potential testing
  • Optional earth line choke (see FN 9255 E versions)
  • All versions comply with IEC/EN 62368-1
  • Medical devices (MDD)
  • In-vitro diagnostic medical devices (IVDD)
  • Computing and accessories
  • LCD and OLED displays
  • Test and measurement equipment
  • Household and similar products as per IEC/EN55014
  • Portable electrical and electronic equipment
  • Small to medium-sized machines
  • Single-phase power supplies, switch-mode power supplies (SMPS)