What are Micro-D connectors?

The tiny but mighty micro-D connector is half the size of a standard D-sub yet delivers rugged and reliable performance in commercial and military applications. 

Micro-D (and nano-D) connectors were derived from D-sub (D-subminiature) connectors in the 1970s. Their compact design led to their early popularity for use in computers. D-sub series connectors were introduced in 1952 by Cannon and these later variants are trademarks of ITT Cannon, though many manufacturers have their own versions.

“New chip technology demanding lower current and voltage made even the large connector companies understand the need for something smaller. At 50 mil, (1.37mm), military specification number 83513 was completed and most large connector manufacturers crowded into the market with their new micro-D standard connectors,” wrote Bob Stanton, director of technology for Omnetics Connector Corporation. “Simultaneously, wire sized at 26 AWG became standard for all circuits handling 3 amperes and lower and were stripped for attachment to the new micro-D. More portable equipment, more insert modules, and smaller instrument and medical electronics embraced this new family of connectors.”

Like D-sub connectors, micro-D connectors are so named because their shape resembles the letter D. Micro-D connectors, however, are about half the size of D-subs, while nano-D connectors are about half the size of micro-D connectors.

Micro-D connectors are also referred to as micro miniature D-Sub connectors. Micro-D connectors feature a minimum of two rows of parallel pins, providing high density in a miniature design. The D-shaped socket or plug fits snugly into the receptacle for a secure mechanical attachment and proper alignment and fit. It also provides EMI shielding. In PCB cable assemblies these connectors save wiring space.

Micro-Ds offer high dielectric strength, low contact resistance, and high current capabilities. The rectangular shield and screw design ensures tight mating and excellent resistance to shock and vibration. Space-grade micro-D backshells also provide strain relief, environmental protection, and grounding.