Military Embedded Systems

PRODUCT OF THE WEEK: Omnetics' rugged, miniature connectors for high-reliability military and space applications

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February 07, 2022

PRODUCT OF THE WEEK: Omnetics' rugged, miniature connectors for high-reliability military and space applications

This week’s product, the Omnetics’ Nano-D Series of rugged connectors, brings users flexibility in defense applications that require rugged interconnectivity in small form factors. This family of connectors meets or exceeds MIL-DTL-32139 requirements for high-reliability applications such as cube sats, LiDAR, phased array radar, and soldier-worn communications devices.

Demand for Smaller Connectors

There is a demand for miniaturization at lower voltages and current levels. As such, nanominiature D-Sub or nano-D connectors serve design engineers well in this new era.

Nano-D connectors are designed to perform at military specification levels for high reliability and to remain working in both portable applications and extreme environments. Most nano-D connectors evolved rather directly from the older micro-D connectors and follow similar specifications. Smaller and better nano-D connector designs often use a 17,200ksi beryllium copper spring-pin-to-solid-socket design to ensure signal integrity during use. As speeds go up, the wavelength of each signal is shorter, and at lower voltages, vibration and circuit noise could confuse the signal. Nano-D connector resistance is kept as low as 12 to 15 milliohms with a capacitance of 2.0pf to 2.4pf, which is ideal for most circuits with low current flow and low voltage.

With increasing speeds, capacitive coupling is also controlled by adjusting the connector insulator spacing to match the specific needs of the application. Low-skew cable technology is evolving to match cable performance to the needs of higher switching and signal speed interconnects.

Family Members 

Included in the Nano D family are Single-Row connectors, Latching connectors, Dual Row connectors, and Panel Mount connectors.

Omnetics' Single Row Nano-D connectors offer an extremely rugged low profile connector which meets or exceeds MIL-DTL-32139 requirements. The ultra-miniature nano connectors are available in a range from SMT for printed circuit board surface mounting to straight tails and wired cable.  Designers use these nano connectors for rugged portable applications in the miniaturization of space satellites and robots to aerospace, military, geophysical, and medical markets.

The Latching Nano-D connectors offer the same rugged high-reliability performance as a standard Nano-D connector while eliminating the threaded hardware (jackscrews) and tools with the Quick Latching connector system. These Latching Nano-D connectors are targeted at applications requiring secure ultra-miniature connectors.

Omnetics' Dual Row Nano-D connectors also meet or exceed the requirements for Mil-DTL-32139.  These rugged high-reliability connectors occupy less space and reduce the weight of the interconnect system for critical miniaturized electronic modules.

The Panel Mount Nano-D connectors are available in a variety of configurations to mount to a board and panel.  These miniature connectors are frequently used in aerospace, military, geophysical, and medical applications.

Within the Nano-D family, Omnetics also offers Bi-Lobe Dust Capas & Metal Covers, and Backshells.

DSP Applications

Portable high-speed digital signal processing (DSP) devices are also expanding the demand for small, lightweight cable and connectors. Nano-D connectors are especially well suited for these ruggedized, environmentally sensitive applications. When specified, cable, signal-speed capability, and formats are designed to match the ultra-small nano-D connectors. Designs include IEEE 1394 fire-wire cable and extend to USB 3.1 formats and CAT 6a wiring. Many of these formats support a wide range of new designs, ranging from circuitry used in small military unmanned vehicles to soldier-worn equipment.

Cyber Security Features 

Metal-shell-to-cable-shield connections will provide additional cyber protection and signal interruptions from devices like jammers, and specially designed insulators, including combinations of power and signal or RF within the connector, will continue to evolve. In addition, high-speed fiber ports will be added to nano-D connectors for special applications and will work especially well in the next phases of photon energy systems. Keep watching the chip and high-speed industry and you will see the applications for nano-D connectors continue to grow.

Other Key Features

•    A 25-position Nano-D connector weighs only 12 grams compared to Omnetics 25-position Micro-D, which weighs more than 47 Grams.   
•    The volume of a 25-position Nano-D connector is 1/8th of that of a Micro-D.   
•    Micro-D connectors are built with a pin to pin spacing, (pitch), for .050”,(1.28mm), that demands similar board layout space.  
•    The nano-d pitch is set at .025”, (.64mm), pin to pin spacing and board layout required is half that of the micro-d.   
•    The maximum Nano-D wire size is 30 and 32 awg, (gauge), based on the cable fitting into the back of the pins and sockets. Current flow will then be limited to 1 ampere maximum, depending on percent of time the current is flowing.  
•    Contact resistance from pin to socket will be at about 15 milliohms and require 2 to 3 oz of mating force per pin.    
•    Back-shells protect EMI and crosstalk from cable to cable or within the instrumentation.  Slip on shielding offer 60 db of shielding and special over braid machines can offer tighter shield windings giving up to 90 db of shielding.   
•    Mating and de-mating ratings in the nano-d military specification only requires 200 mates before the plating fails and resistance of the connection increases.  Watch for nano-d connector suppliers that offer over 2000 mates before plating fails giving more useful life of connectors in frequent use.
•    Plating should be specified to meet ASTBM B488 Type II which includes 50 micro-inches of Gold over 50 micro-inches of nickel.  
•    Nano-D connectors have been tested and used in high shock above 10,000 Gs when fired from military ballistic devices, such as THAAD missile interceptor systems.   Extreme temperature ranges are similar to Omnetics Micro-D connectors and easily pass operating temperatures from -55°C to +200°C.   

For more information, visit the Nano-D page here, or visit the company’s website, or follow the links below.

Resources: 
•    Download Omnetics Nano-D Catalog, click here.
•    Read Omnetics Newsletter, click here.
•    For sales information, click here.
 

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