Electronics Protection - Summer 2017 - 24

EMI/EMC/RFI
Premier Magnetics Drum Cores for EMI Filtering and Switch Mode Power Supplies
Premier Magnetics has introduced its new line of low-cost, high-performance drum core inductors designed for EMI filtering and switch mode power supply applications. With a product offering of over two dozen models with inductance values from 100 to 10,000 µH, the
new PM-R series boasts low dc resistance (DCR), providing low temperature rise at high peak
currents. Their combination of high peak current and high self-resonant frequency (SRF)
make the PM-R Series inductors an ideal drop-in replacement for lower-performing drum
core devices. And in applications where the devices' maximum height of 10.0 to 11.5 mm is
acceptable, the PM-R Series offers a cost-effective alternative to surface-mount inductors.

Premier Magnetics' PM-R drum core inductors are offered in two series, PM-R2 (7.5 mm, dia.
x 10.0 high, max) and PM-R3 (9.5 mm, dia. x 11.5 high, max), each offering models with a
range of 100 µH to10 mH. Both series of inductors are available with sleeving (125°C); and without sleeving (155°C).
Standard operating temperature range is -40C to 130C, with higher temperatures available. The radial-leaded components are RoHS compliant.

Ultra-Thin Magnetic Sheets with High Permeability

TDK Corp. has expanded its Flexield family of noise suppression sheets with an ultra-thin copper-clad laminated
sheet with high magnetic permeability. The new IFM10M magnetic sheets are 60 percent thinner than existing sheets
with a magnetic layer of the same thickness, but offer an equivalent noise suppression performance over a broad
frequency range from 500 kHz to 10 GHz. The total thickness of the new Flexield sheets is just 0.04 mm. The size of
the sheets is 300 mm by 200 mm. Volume production is scheduled to begin in June 2017.
This improvement was made possible by TDK's unique laminated design: The IFM10M sheet consists of a magnetic
layer and a copper-plated layer of polypyrrole resin and no longer requires a layer of double-sided tape. With these
sheets TDK has succeeded in creating an ultra-thin copper cladding of just 1 µm based on plating process technology
developed by Achilles Corporation. Thanks to their low profile, the new Flexield IFM10M noise suppression sheets
are suitable for use in slim devices such as smartphones, tablets, notebooks and stylus pens.
As electronic devices, including smartphones, have become smaller and thinner as well as more multifunctional with
a higher degree of integration, the need for better and more efficient noise suppression is growing, for example, to
ensure the reliable function of NFC (near-field communication) and wireless charging in the same device. In addition
to noise suppression within the circuit using EMC components and standard circuit design measures and, it is essential to suppress unexpected and unwanted interference. Magnetic sheets are used to absorb noise and prevent from
leaking externally or reflecting internally.

Miniaturized LC Filters for Suppression of EMI

TDK Corp. has released the MEM1005PP251T - A LC filter for EMI suppression. With dimensions of just 1.0 by 0.5 by
0.35 mm the filters are well suited for use in smart phones and base stations.
The usual method for suppressing interference in the communication frequency bands of smart phones and other
devices is to use capacitors or inductances, or a combination of these components. In contrast to discrete solutions,
the MEM1005PP251T combines two capacitors and an inductance in the form of a Pi filter in a single component. As
a result, 61 percent less space is required and there is a reduction in the overall number of components.
The component offers very low-loss operation and a DC resistance of just 0.8 Ω, which represents a reduction of 69
percent when compared to previous products. The new filter offers a rated current of 350 mA, which is 3.5 times
more than the MEM1608P series. With these properties the combination element offers the highest possible performance currently available in its class.* In addition, the new filter is designed for a very wide temperature range from
-55 °C to 125 °C, whereas previous series only covered the range from -40 °C to 85 °C. Due to expansion of rated
current and the wide temperature range, it allows a high degree of design flexibility.
The attenuation in the frequency range from 700 MHz to 3 GHz, which is used by mobile communications, is in excess
of 30 dB. This means that interference is extremely well suppressed and the reception sensitivity increases significantly.
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Summer 2017 * www.ElectronicsProtectionMagazine.com

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Table of Contents for the Digital Edition of Electronics Protection - Summer 2017