Amorphous magnetic cores allow smaller, lighter and more energy efficient designs in many high frequency applications for Invertors, UPS, ASD (Adjustable speed drives), and Power supplies (SMPS). Amorphous metals are produced in using a rapid solidification technology where molten metal is cast into thin solid ribbons by cooling at a rate of one million°C/second. Amorphous magnetic metal has high permeability due to no crystalline magnetic anisotropy.

Nanocrystalline cores improve on standard Amorphous magnetic properties by a highly controlled annealing process to create a uniform and very fine nanocrystalline microstructure with grain sizes of ~10nm providing 1/5th the core loss of Fe based amorphous metal.

Amorphous magnetic cores have superior magnetic characteristics, such as lower core loss, when compared with conventional crystalline magnetic materials. These cores can offer superior design alternative when used as the core material in the following components:

• AC Reactor
• DC Inductor
• PFC Boost Inductor: Under 6kW (microlite 100µ) and over 6kW
• Common Mode Chokes
• MagAmp
• Differential Mode Chokes / SMPS Output Inductor
• Spike Absorbing Cores
• CT's using Amorphous Magnetic Cores
• High Frequency Low Loss Transformers

Technical advantage

Where typical ferrite cores can only operate up to a flux saturation level (B_sat) of 0.49 Tesla, an amorphous metal core can operate at 1.56 Tesla. Combined with operating at permeability similar to high-end ferrites and the flexibility of manufacturing large cores sizes these cores can be an ideal solution for many of these components.

Nanocrystalline amorphous metal offers size, core and labor savings for various power conversion and EMC applications.

Three phase designs can be done with standard single-phase cores or a custom three-phase amorphous metal core can be constructed in a two-piece set as shown.

These amorphous cores wound in a C-core configuration, are ideal for AC Reactors and DC inductors from 10 to 1000+ amperes. The C-core also allows for single phase and three phase transformer designs.

Amorphous metal C-cores allow for operation at higher frequencies at the same flux level. Where traditional steel cores need to operate at increasingly lower flux densities as the frequency increases. In order to compensate for running at lower flux densities significantly more material is needed. Even with additional material higher temperatures still occur. Another contributor to lowering losses is the I²R of the winding. A physically smaller amorphous core reduces your mean length per turn, hence your I²R copper losses are lower and copper costs are lower. Further improvements can be realized by using Nanocrystalline C-Cores.

We produce rectangular shapes of amorphous metal cores by stacking layers of laminations made from amorphous metal ribbon. An adhesive rated for a continuous operating temperature of 155°C holds the laminations together.

These forms offer a unique combination of high saturation induction (1.56 T), high permeability and low core loss and can be configured into various shapes, allowing for one large gap to be distubuted across several smaller gaps, reducing fringing flux, and core loss.

Hybrids can be designed using c-core sections with corresponding bricks for unique shapes

Applications: Medium Frequency and High Power Inverters

Technical data sheet

This is an amorphous alloywhich also non-crystalline in nature. Metglas® MICROLITE XP cores operate cooler and have lower core losses than cores made of conventional crystalline materials such as powdered iron, ferrite or sendust. MICROLITE XP's energy-efficient properties reduce the size of powder sources for demanding applications in the electronics industry.

Applications: Differential Input Inductors, PFC Inductors, Flyback transformers, and VRM Inductors.

Links and data sheets for download:

• Specifications for ordering: MicroLiteXP Toroidal Cores
• Core Loss vs. Flux Density @ 25°C
• Percent Permeability vs. dc Bias
• Temperature Dependence of Inductance 
• Temperature Dependence of Inductance and Permeability vs. Frequency
• Core Specifications  

Core Data Sheet

• Technical Bulletin

These cores are manufactured with cobalt-based Metglas® amorphous alloy 2714A for high frequency applications. Theses flat loop toroidal cores offer a unique combination of ultra-high permeability, high saturation flux density and extremely low core loss for electronic component designers.

Applications: EMI Common Mode Filtering; Telecommunications and Data Communications Interface Transformers; High Accuracy Current and Pulse Transformer Ground Fault Protection Devices.

Links and data sheets for download:

• Specifications for ordering: MagnaPerm High Permeability Cores
• Core Loss vs. Flux Density @ 25°C
• Percent Permeability vs. Multiple Variables
• Core Specifications  

Core Data Sheet

• Technical Bulletin

These cores are manufactured with cobalt-based Metglas® amorphous alloy 2714A which allow the design of MAG AMP that can operate at higher frequencies than previously possible. Their combination of magnetic properties enables these MAG AMP cores to provide unparalleled precision and efficiency in output regulation. Available in both coated and boxed cores.

Microlite 100μ

Advanced Amorphous A-AL

These cores are manufactured by pulverizing amorphous ribbon and pressing this powder into toroidal shapes, using amorphous alloy. allowing the designer of PFC boost inductors to reduces size and power loss as compared to conventional solutons. This A-AL material is a unique in its combination of low core loss and high DC bias which enables these cores to provide unparalleled precision and efficiency. Contact us for availablity in both coated and boxed cores.

Common Mode Chokes (CMC) made with Nanocrystalline material have superior characteristics when compared to the most commonly used material Mn-Zn ferrite.

Higher permeability

The potential of designing a smaller CMC with the same number or fewer turns is of interest to many designers. Nanocrystalline materials offer this possibility by providing a complex permeability (µr at 100kHz and 20C), which is more than twice that of Mn-Zn ferrite. The impedance relative permeability (µrz) is more than four times as high as Mn-Zn ferrite. In one case this allows the designer using Nanocrystalline material to use a core of identical size to Mn-Zn ferrite which will produce four times higher impedance with the same number of turns. In another case the designer can use this material to reduce the windings by ½ and to obtain the same low frequency impedance significantly reducing stray capacitance, as a result high frequency impedance also becomes large.

The below charts show the higher impedance benefit of nanocrystalline material verses Mn-Zn ferrite.

FT-3KM nanocrystalline

Single-phase cores

For the designer interested in winding an inductor for a specific application we have available the following standard cores for single-phase requirements. These are toroidal shaped tape-wound cores made from nanocrystalline amorphous metal. The below table lists; Product code and part number for cores made with FT-3KM material and new FT-3KM50T upgraded version of FT-3KM.

FT-3KM - K Series

FT-3K50T - K Series

Three-phase cores

For the designer interested in winding an inductor for a specific application we have available the following standard cores for three-phase requirements. These are toroidal shaped tape-wound cores made from nanocrystalline amorphous metal. The below table lists; Product code and part number for cores made with FT-3KM material.

If you require much larger cores for common mode chokes with rated currents over 100Amps these cores offer you the size to solve these RF noise problems.

They can be used for signal lines, DC power lines, and AC power lines. Because of the low magnetostriction these core also provide low audible noise. Cores with base plate only, require cabling with the appropriate BIL insulation for the voltage being used. L type cores are used when a DC offset is present, see BH curves.

M type cores with base and base plate combined

Standard wound common mode and choke cores are available as standard products for DC and single-phase AC power lines (rated current from 5A to 40A), and for three-phase AC power line (rated current from 3A to 600A).

Custom designs are available upon request, for your application you can pick the standard product that most closely meets your needs, or fill out our request form for a recommendation.

Typical applications include various portions of the power supply / inverter such as input single and three phase noise filters, active harmonic filters, output noise filters, DC Power Lines or Signal Lines.

Our NANO amorphous tape-wound cores are used in (SMPS) Switched-Mode Power Supplies, Frequency Inverters, ASD and UPS and other applications for effective noise suppression caused by rapid changes in current. The high pulse permeability of these cores allow excellent performance in the suppression of reverse recovery current from the diode and ringing or surge current from switching circuit. The Surge Absorber Cores are normally used as single-turn choke or with very few turns

The saturation magnetic flux density is twice as high as that of Co-based amorphous metal and three times higher than that of Ni-Zn ferrite. The pulse permeability and the core loss are comparable to Co-based amorphous metal. As a result, a small core made of this material offers higher performance in suppression of surge current and voltage.

These cores also feature low core losses and a very high squareness of the BH hysteresis loop resulting in a high inductance when the current crosses zero. This high inductance effectively blocks reverse recovery currents created by diodes. The material saturates at relative small currents. Thus, spike blocking is not possible at DC currents.

Toroidal type bead core

Horizontal and vertical mounted leaded cores

These cores are used for medium and large power and are toroidally wound cores which show excellent performance for the suppression of various kinds of current or voltage surge, such as a surge from a switching diode.

Core range in size from outside diameters of 11 to 38mm and inside diameters of 4 to 22mm.

Annealing changes BH loops

M type material is done with no magnetic field applied during annealing

M type material is done with no magnetic field applied during annealing We produce H and L type BH loops by annealing with magnetic fields oriented either parallel or perpendicular to the ribbons surface.

• High saturation magnetic flux density, more than 1 Tesla 
• High permeability over 10,000u at 100kHz
• Excellent temperature characteristics. Very high Curie temperature (570°C) resulting in small permeability variation (less than +/-10%) at a temperature range of -40°C to 150°C.
• Less affected by mechanical stress.  Because of the low magnetostriction permeability and core loss changes have very small changes.
• Very low audio noise emission. Lower magnetostriction significantly reduces audible noise emission when the voltage and current applied to the core at audible frequency range.

The casting process

Ribbon is cast in widths up to 8 inches in wide and then is slit to width required for winding. Special winding machines wind the ribbon in to various Toroidal, Oval and C-core shapes. Cores then are further process via cutting, coating, annealing according to standard offering and customer requests.