Product Roundup: EMI/RFI shielding and packaging

Product Roundup: EMI/RFI shielding and packaging

In order for any electronic device to run efficiently, it’s important to make sure that they are properly shielded against harmful EMI/RFI interference. Many products today can be found with protection built right in.

Released late last year, the Nemesis Series of miniature circular connectors from ITT Industries (www.ittcannon.com) provides 360° EMI shielding. The 73.00 x 19.50-mm connectors are fully sealed to IP67/IP68 specifications and also feature pogo pin/pad and breakaway technologies, guaranteeing over 10,000 mating cycles.

ITT’s Nemesis Series miniature circular connectors

Available with RoHS-compliant black zinc nickel or electroless nickel plating, the connectors suit a range of consumer, medical, and industrial handheld and mobile devices.

Premo (www.grupopremo.com) recently released its FEDC Series EMC filters, which reduce conducted emissions toward and EMI radiation from the solar panel in PV inverters. The filters offer ratings from 25 to 1,500 Adc; without terminals they offer up to 150 Adc, and with screw connections up to 1,500 Adc. Maximum operational voltage is 1,200 Vdc. The filters are also available without capacitor to ground.

The RoHS-compliant filters meet EN60939 and UL1283 EMC requirements and are also suited for dc applications, such as fuel cells and batteries.

PREMO’s EMC filters for PV applications

A recent addition to the Datamate series from Harwin (www.harwin.com), the S-Tek hi-rel connectors have single-piece, machined-metal backshells that protect against EMI/RFI interference in I/O applications. The backshells are designed to attach to a wide variety of standard metallic braids and enable the shield braid to be connected through the backshell to the PCB ground plane. The S-Tek connectors are available in female cable-to-PCB-mount and female cable-to-panel-mount configurations in sizes including 6, 10, 14, 20, and 26 positions.

Harwin’s Datamate S-Tek hi-rel connectors

Shielded enclosures

Last month, Verotec (www.verotec.us) unveiled its Veroshield 19-in. EMC-screened rack cases. The enclosures were designed so users could easily mount a wide range of electronic, electric, and electro-mechanical gear in an enclosure with good EMC performance (typical attenuation exceeds 110 dB to 10 MHz.)

The company says the cases — which are available in three sizes: 1U x 10.4 in. deep and 2U and 3U x 14.4 in. deep — are particularly useful in larger 19-in. rack-mounted systems where only some elements require elevated levels of protection. The units are not only inexpensive — a 1U enclosure costs less than $99 in single quantities — but can also be used to provide screening for desktop systems.

In March, Verotec introduced the Diplomat family, a group of stylized enclosures that include EMC-capable units suitable for housing stand-alone systems, 19-in. caseframes for direct mounting of boards and modules, and as vertical tower units. Available off-the-shelf in 3, 4, 6, and 9U heights and depths of 12.7, 16.6, 20.6, and 24.5 in., they are intended for medical technology application, the research environment, and as housings for desktop instruments.

Verotec’s Diplomat enclosures

In February, Optima EPS (www.optimaeps.com) began offering cabinets based on its M-series that are fully tested to MIL-STD-461D specifications for EMC. Units in the series have a steel or aluminum frame, shielded door handles, wrap-foam gasketing around the door with conductive adhesives, EMI filters, copper gasket fingers, and steel-mesh gasket strips.

Optima EPS’s EMC-tested M-series enclosures

Optima can also provide creative EMC solutions for advanced shielding requirements. For example, it can incorporate tin-plating or other conductive metal surfaces with superior electrical continuity properties to help reduce offending radiated emissions. The company can provide a minimum electric field attenuation of 60 dB from 100 kHz to 1 GHz, using cost-effective materials.

Early in the year, Hammond Manufacturing (www.hammondmfg.com) added nine sizes to its 1550 family of die-cast aluminium enclosures. Designed to provide robust mechanical protection and good EMC attenuation, the enclosures use tapped holes and machine screws to secure the lid to suit applications where interior access is required on a regular basis. Available with a natural or black epoxy powder coated finish, the units are supplied in two versions, standard and watertight, in sizes ranging from 2.36 x 2.17 x 1.02 in. to 10.83 x 6.89 x 2.46 in..

Hammond Manufacturing’s 1550 series die-cast aluminium enclosures

To learn more about the technical aspects of choosing shielding for enclosures, see “Selecting EMP protection for enclosures” by Praveen Pothapragada, Chief Engineer, Equipto Electronics ( www2.electronicproducts.com/S-article-farc_equipto_apr2011-html.aspx). The article shows you how to calculate the correct level and materials you need.

Christina D’Airo and Richard Comerford