D Subminiature Connector
A D Subminiature Connector (there were many less-formal versions of the name, such as D-Sub) was a family of low-current signal connectors, much used in computer gear of the 1970's though 1990's. They were invented by Cannon in 1952; they were subsequently adopted by the US military, as Mil Standard 24308 (later 83513). An international standard, IEC 60807-3 / DIN 41652, is now also available for them.
They have two or three (and in a few rare cases, four) parallel rows of pins or sockets, surrounded by a trapezoidal sheet-metal shell with rounded corners. (The shell is reportedly the origin of the name; it is roughly 'D'-shaped.) The shell provides correct orientation and alignment (as it is being plugged in), mechanical support (once it is plugged in), and a certain amount of protection from electro-magnetic interference.
They have part numbers of the form 'Dsxxg', where 's' is the physical shell size (E, A, B, C, D, from smallest to largest), 'xx' is the number of pins, and 'g' is the gender ('P' = plug/male, 'S' = socket/female; occasionally 'M' = male, 'F' = female). (The gender of a connector is set by whether it has pins or sockets, not by the form of the outer shell; D-Subs have contacts of one gender but a shell of the other form; e.g. male pins with a female shell.)
When they first appeared, they were set up to allow individual wires to be soldered into the pins; later, ones were produced which could be crimped onto flat cables. Later still, variants appeared which had pins on the back, allowing them to be attached to printed circuit boards using through-holes. Wire-wrap versions are also to be found.
Uses
The first major use to which D-Sub connectors were put were EIA serial lines, using DB25 connectors. They were later used for serial lines on IBM PCs and IBM-compatible PCs, but with physically smaller DE9 connectors. They were also used for Ethernet, for the standard Attachment Unit Interface (AUI), using DA15 connectors.
External links
- D-Subminiature Connectors Explained
- ITT Cannon D Subminiature Connectors
- Connectors, Electrical, Rectangular, Microminiature, Polarized Shell, General Specification for - the Mil Spec standards
- MIL-DTL-83513/25D Detail Specification Sheet - Dx9 through Dx37
- MIL-DTL-83513H Detail Specification - information on included specifications
