New Industry Products

Kemet Announces a Series of Nanocrystalline Single-Phase Filters

January 17, 2021 by Gary Elinoff

The new devices are aimed at reducing the electromagnetic interference (EMI) generated in single-phase, 250 VAC power lines

Kemet’s GTX series come five separate current classes, ranging from 6 to 30 amps. Each is offered with any of six groupings of Class-Y capacitors, for a total of 30 combinations, supporting a wide range of applications. 


GTX Series member GTX-2300-YXX
GTX Series member GTX-2300-YXX. Image courtesy of data sheet


Encased in plastic boxes, members of the GTX series of single phase filter will serve to suppress conducted electromagnetic noise that would otherwise be detrimental to the proper operation of electronic circuitry.


What is that’s Special about Nano-Crystalline Cores?

Ferrite is a well-known soft magnetic material widely employed as the core material for inductors of all types. Nanocrystalline is a new material that, when substituted for ferrite, produces far more magnetic flux if physical size and current are kept the same. It then follows that inductors based on nanocrystalline will be smaller than their equivalents based on ferrite.


How Does it Work?

While the atomic structure of most magnetic materials are periodic and regular, nanocrystalline structure is randomized. The illustration below illustrates the contrast.


Kemet Announces a Series of Nanocrystalline Single-Phase Filters Figure
Image courtesy of Mouser and Hitachi


The image on the left illustrates the randomized structure of Hitachi’s nanocrystalline material. The key to the efficacy of nanocrystalline materials is that their randomized nature facilitates the electromagnetic process of generating flux.

Due to their nanocrystalline core, members of the GTX series are physically smaller, feature for feature, than their ferrite-based competition.

The data sheet provides extensive graphical illustration of insertion losses at different EMI frequencies for all 30 variants of the GTX family.


GTX Series Specifics

All units are rated for 250 VDC and 560 VAC. Maximum temperature rise is 60°K

There are five available current ratings, and within each current rating, the customer has a choice of 6 different capacitor lineups, with each group of capacitors manifesting a different leakage current. 


Internal structure of the GTX series.
Internal structure of the GTX series. Image courtesy of the data sheet


Referring to the diagram above:

Kemet Suffix CY1 CY2 Leakage Current in milliamps
Y00 None None 0.01
Y02 None 2,200pF 0.50
Y03 None 3,300pF 0.75
Y0X None 10,000pF 2.30
Y22 2,200pF 2,200pF 1.00
YXX 10,000pF 10,000pF 4.60


It is important to note that Class Y capacitors are designed to go open circuit if they fail. If they fail closed, they can compromise the ground connection, exposing operators to a potentially lethal shock hazard. We go into detail about Class Y capacitors in a previous article.

All units can withstand 1,500 VAC, line to ground, for 1 minute.

Insulation resistance is a minimum of 300 megaohms at 500 VDC for 1 minute, line to ground.



Members of the GTX series will find application in the inverters used in

  • Welders
  • Commercial equipment
  • Industrial applications
  • Medical equipment
  • 3D printing


Physical specifications

  • Dimensions are approximately 75 by 44 by 25 mm
  • Series members all feature screw terminals
  • Weight ranges from 123 to 132 grams
  • The units all operate over a temperature range of −25 to +55°C  


Approvals and Environmental Compliances

  • RoHS compliant
  • TÜV Rheinland Japan Ltd approved
  • UL/c-UL approved