The D-subminiature or D-sub is a common type of electrical connector used particularly in computers. An electrical connector is a conductive device for joining Electrical circuits together A computer is a Machine that manipulates data according to a list of instructions. Calling them "subminiature" was appropriate when they were first introduced, but today they are among the largest common connectors used in computers.
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Description and nomenclature
A D-sub contains two or more parallel rows of pins or sockets usually surrounded by a D-shaped metal shield that provides mechanical support and some screening against electromagnetic interference. DB13W3 (also known simply as 13W3) is a particular style of D-subminiature connector commonly used as an analog video interface connector that was DB13W3 (also known simply as 13W3) is a particular style of D-subminiature connector commonly used as an analog video interface connector that was The D shape guarantees correct orientation. The part containing pin contacts is called the male connector or plug, while that containing socket contacts is called the female connector or socket. The socket's shield fits tightly inside the plug's shield. The shields are connected to the overall screens of the cables (when screened cables are used), creating an electrically continuous screen covering the whole cable and connector system.
D-subminiature connectors were invented by ITT Cannon, part of ITT Corporation, in 1952. For other uses of " cannon " including other companies called " Cannon " see Cannon (disambiguation. ITT Corporation, is a global diversified manufacturing company with 2007 revenues of $9 Year 1952 ( MCMLII) was a Leap year starting on Tuesday (link will display full calendar of the Gregorian calendar. [1] Cannon's part-numbering system uses a D as the prefix for the whole series, followed by a letter denoting the shell size (A=15 pin, B=25 pin, C=37 pin, D=50 pin, E=9 pin), followed by the actual number of pins, followed by the gender (P=plug, S=socket). In Electrical and mechanical trades and manufacturing each of a pair of mating connectors or Fasteners is conventionally assigned the designation male [2] For example, DB25 denotes a D-sub with a 25-pin shell size and 25 contacts. The contacts in these connectors are spaced approximately 0. 108 inches (2. 74 mm) apart with the rows spaced 0. 112 inches (2. 84 mm) apart.
Cannon also produced D-subs with larger positions in place of some of the normal pin positions that could be used for either high-current, high-voltage, or co-axial inserts. The DB13W3 variant was commonly used for high-performance video connections; this variant provided 10 regular (#20) pins plus three coaxial contacts for the red, green, and blue video signals. DB13W3 (also known simply as 13W3) is a particular style of D-subminiature connector commonly used as an analog video interface connector that was
In the photograph below, the connector on the left is a 9-pin (DE-9) connector plug, and the one on the right is a 25-pin (DB25) socket. The hexagonal pillars at either end of each connector have a threaded stud (not visible) that passes through flanges on the connector, fastening it to the metal panel. They also have a threaded hole that receives the jackscrews on the cable shell, to hold the plug and socket together. Screwshavings2 smPNG|thumbnail|Damaged jackscrew recovered from Alaska Airlines Flight 261]] A jackscrew is a type of jack which is operated by turning a Leadscrew
Possibly because the original PC used DB25 connectors for the serial and parallel ports, many people, not knowing the significance of the letter "B" as the shell size, began to call all D-sub connectors "DB" connectors instead of specifying "DA," "DC" or "DE. In Computing, a serial port is a Serial communication physical interface through which information transfers in or out one Bit at a time (contrast A parallel port is a type of interface found on Computers ( personal and otherwise for connecting various peripherals " When the PC serial port began to use 9-pin connectors, they were often called "DB9" instead of DE9. It is now common to see DE9 connectors sold as "DB9" connectors. DB-9 is nearly always intended to be a 9 pin connector with an E size shell.
There are now D-sub connectors which have the original shell sizes, but more pins, and the names follow the same pattern. For example, the DE15, usually found in VGA cables, has 15 pins, in three rows, in an E size shell. A VGA connector as it is commonly known (other names include RGB connector D-sub 15 mini sub D15 and mini D15 is a three-row 15 pin DE-15. The full list of connectors with this pin spacing is: DE15, DA26, DB44, DC62, and DD78. Alternatively, following the same confusion mentioned above in which all D-sub connectors are called "DB", these connectors are often called DB15HD, DB26HD, DB44HD, DC62HD, and DD78HD, where the "HD" stands for "high density". They all have 3 rows of pins, except the DD78, which has 4.
A series of D-sub connectors with even denser pins is called "double density", and consists of DE19, DA31, DB52, DC79, and DD100. They have 4 rows of pins.
There is yet another similar family of connectors that is easy to confuse with the D-sub family, but is not part of it. These connectors have names like "HD50" and "HD68", and have a D-shaped shell but the shell is about half the width of a DB25. They are common in SCSI attachments.
The suffixes M and F (male and female) are sometimes used instead of the original P and S (plug and socket).
The original D-subminiature connectors are now defined by an international standard, DIN 41652. Deutsches Institut für Normung eV ( DIN; in English, the German Institute for Standardization) is the German national organization for
Typical applications
Left: DE9M Right: DB25F.
The widest application of D-subs is for RS-232 serial communications, though the standard did not make this connector mandatory. In Telecommunications, RS-232 (Recommended Standard 232 is a standard for serial binary data signals connecting between a DTE ( Data Terminal Equipment RS-232 devices originally used the DB25 25-pin D-sub, but for many applications the less common signals were omitted, allowing a DE9 9-pin D-sub to be used.
On PCs, 9-pin and 25-pin plugs are used for the RS-232 (serial) ports and 25-pin sockets are used for the (parallel) printer ports (instead of the Centronics socket found on the printer itself). In Telecommunications, RS-232 (Recommended Standard 232 is a standard for serial binary data signals connecting between a DTE ( Data Terminal Equipment IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices
A male DE9 connector on the back of an IBM-PC-compatible computer is typically a serial port connector. A computer is a Machine that manipulates data according to a list of instructions. In Computing, a serial port is a Serial communication physical interface through which information transfers in or out one Bit at a time (contrast IBM introduced the DE9 connector for RS-232 on PCs with the Personal Computer AT in 1984. A female 9-pin connector on the same computer may be a video display output: monochrome, CGA, or EGA. The Monochrome Display Adapter ( MDA, also MDA card, Monochrome Display and Printer Adapter, MDPA) introduced in 1981 was IBM The Color Graphics Adapter ( CGA) originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter The Enhanced Graphics Adapter (EGA is the IBM PC Computer display standard specification located between CGA and VGA in terms of graphics Even though these all use the same connector, the displays cannot all be interchanged and monitors or video interfaces may even be damaged if connected to an incompatible device using the same connector. Later analog video (VGA and later) adapters replaced these connectors by DE15 15-pin high-density sockets, which have three rows of five contacts each in the space that was previously occupied by two rows of five and four contacts. The term Video Graphics Array ( VGA) refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987, but through its widespread A VGA connector as it is commonly known (other names include RGB connector D-sub 15 mini sub D15 and mini D15 is a three-row 15 pin DE-15. Other common names for DE15 connectors are HD15, where HD stands for High Density, and (less accurately) DB15 and DB15HD.
From the late 1970s and all through the '80s, DE9s without the pair of fastening screws were almost universal as game controller connectors on video game consoles and home computers, after being made a de facto standard by the use of such game ports in the Atari 2600 game console and the Atari 8-bit family of computers. A game controller is an Input device used to control a Video game. A home computer was a class of Personal computer entering the market in 1977 and becoming common during the 1980s The Atari 2600 is a Video game console released in October 1977 The Atari 8-bit family is a series of 8-bit Home computers manufactured from 1979 to 1992 Computer systems which use them include Atari, Commodore, Amiga, Amstrad, and SEGA systems, among others, but exclude Apple and PC systems and most newer game consoles. Atari is a corporate and brand name owned by several entities since its inception in 1972. Commodore, the commonly used name for Commodore International, was a US-American Electronics company based in West Chester Pennsylvania The Amiga is a family of Personal computers originally developed by Amiga Corporation. Amstrad is an electronics firm based in Brentwood in Essex, England and founded in 1968 by Sir Alan Michael Sugar in the is a multinational Video game Software and Hardware development company and a former Home computer Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Used in the standard way, they support one digital joystick and one pair of analog paddles; on many systems a computer mouse or a light pen is also supported through these sockets, however these mice are not usually exchangeable between different systems. A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling A paddle is a Game controller with a round wheel and one or more fire buttons, where the wheel is typically used to control movement of the player object In Computing, a mouse (plural mice, mouse devices, or mouses) A light pen is a Computer Input device in the form of a light-sensitive wand used in conjunction with a the computer's CRT TV set or monitor DE9 connectors are also used for some token ring and other computer networks. Token ring Local area network (LAN technology is a local area network protocol which resides at the Data link layer A computer network is a group of interconnected Computers. Networks may be classified according to a wide variety of characteristics DA15 is used for Ethernet Attachment Unit Interface. An Attachment Unit Interface ( AUI) is a 15 pin connection that provides a path between a node's Ethernet interface and the Medium Attachment Unit (MAU
Many uninterruptible power supply units have a DE9F connector on them, in order to signal to the attached computer. An uninterruptible power supply ( UPS) also known as a continuous power supply ( CPS) or a battery backup is a device which maintains a continuous A signal is a limited form of Inter-process communication used in Unix, Unix-like, and other POSIX -compliant operating systems Often these do not send data serially to the computer but instead use the handshaking control lines to indicate low battery, power failure or other conditions. Such usage is not standardized between manufacturers and may require special cables to be supplied.
The complete range of D-sub connectors also includes 15-pin DA15s (two rows of 7 and 8); 37-pin DC37s (two rows of 18 and 19); and 50-pin DD50s (two rows of 17 and one of 16), the last two being used in industrial products. A printed circuit board, or PCB, is used to mechanically support and electrically connect Electronic components using conductive pathways or traces The 15-pin DA15 has been notably used for color video output on early Macintosh computers and as the IBM-defined analogue joystick port on PCs (where it is female). Macintosh, commonly nicknamed Mac is a Brand name which covers several lines of Personal computers designed developed and marketed by Apple Inc A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling Many third-party PC sound cards, particularly the Sound Blaster line from Creative Labs, included a variation of the IBM joystick port using the same connector but taking two of the pins to add a (usually MPU-401 compatible) MIDI interface. The DA15F was also used for the AUI connectors included on Ethernet cards in the 1980s and 1990s, albeit with a sliding latch to lock the connectors together instead of the usual hex studs with threaded holes. An Attachment Unit Interface ( AUI) is a 15 pin connection that provides a path between a node's Ethernet interface and the Medium Attachment Unit (MAU Finally, the early Macintosh and Apple II line of computers used a very rare 19 pin D-sub for connecting to external floppy disk drives, and the Commodore Amiga used an unusual 23-pin version for both its video output and for connecting an external floppy drive. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased The Amiga is a family of Personal computers originally developed by Amiga Corporation.
TASCAM used DB25 connectors for their multi-track recording audio equipment (TDIF), and Logitek Audio later did the same for its broadcast consoles, though with different pinouts. TASCAM is the professional audio division of TEAC Corporation, headquartered in Tokyo Japan, and is credited as the inventor of the Portastudio, the first Multitrack recording ('multitracking' or just 'tracking' for short is a method of Sound recording that allows for the separate recording of multiple sound sources to create Pinout is a term used in Electronics to describe how an Electrical connector is wired [1] A few patch panels have been made which have the DB25 connectors on the back with phone jacks (or even TRS jacks) on the front, however these are normally wired for TASCAM, which is more common outside of broadcasting. A patch panel or patch bay or jackfield is a panel typically Rackmounted that houses Cable connections A TRS connector, also called an audio jack, phone plug, jack plug, stereo plug, mini-jack, or mini-stereo, is a common For the band see Broadcast (band Broadcasting is the distribution of audio and/or Video signals which transmit
In broadcast and professional video, "parallel digital" is a digital video interface that utilizes DB25 connectors, per the SMPTE 274M specification adopted in the late 1990s. Digital video is a type of Video recording system that works by using a Digital rather than an analog video signal The more common SMPTE 259M "serial digital interface" (SDI) utilizes BNC connectors for digital video signal transfer. SMPTE 259M is a standard published by SMPTE which " describes a 10-bit serial digital interface operating at 143/270/360 Mb/s Serial digital interface (SDI refers to a family of Video interfaces standardized by SMPTE. Serial digital interface (SDI refers to a family of Video interfaces standardized by SMPTE. The BNC ( Bayonet Neill Concelman) connector is a very common type of RF connector used for terminating Coaxial cable.
Types and variants
D-sub connectors exist in at least five types, differentiated by the method used to attach wires to the contacts. These are solder-cup or solder-bucket, insulation displacement, crimp, PCB pins, and wire wrap.
- Solder-bucket contacts have a cavity into which the stripped wire is inserted and hand-soldered (a somewhat tricky process especially to do alone as the wire can easily pop out of the bucket whilst soldering unless held there).
- Insulation displacement contacts (IDC) allow a ribbon cable to be forced onto sharp tines on the back of the contacts; this action pierces the insulation of all the wires simultaneously. An insulation displacement connector or Insulation piercing connector is a connector that pierces the insulation on a Wire to make the connection removing the need A ribbon cable (also known as multi-wire planar cable is a cable with many conducting wires running parallel to each other on the same flat plane This is a very quick means of assembly whether done by hand or automatically but requires use of flat ribbon cable which can be awkward to handle and makes it difficult to make cables with different connections at each end.
- Crimp contacts are assembled by inserting a stripped wire end into a cavity in the rear of the contact, then crushing the cavity using a crimp tool causing it to grip the wire tightly at many points. The crimped contact is then inserted into the connector where it locks into place. Individual crimped pins can be removed later with a tool inserted into the rear of the connector. This "rear release" feature is valuable when pins are damaged or modifications must be made to the circuits.
- PCB pins as the name suggests are intended to be soldered directly to a printed circuit board and not to a wire. A printed circuit board, or PCB, is used to mechanically support and electrically connect Electronic components using conductive pathways or traces These connectors are frequently mounted at a right-angle to the PCB allowing a cable to be plugged into the edge of the PCB assembly. Blocks containing multiple stacked D connectors (and sometimes other connectors too) are nearly always seen on ATX (or variants thereof) PC motherboards but aren't generally seen elsewhere. The ATX (for Advanced Technology Extended) form factor was created by Intel in 1995.
- Wire wrap connections are made by wrapping solid wire around a square post with a wire wrap tool. This article deals with electronics manufacturing and prototyping techniques see Wire wrap jewellery for the Jewellery related topic Abisolierwerkzeug This type of connection is usually used in prototyping.
A smaller type of connector derived from the D-subminiature, and about half the linear size, is called the microminiature D, or micro-D, which is a trademark of ITT Cannon. This connector is used in industrial instrumentation products. A few manufacturers make nano-D connectors, which are about half the size again.
Usage
The 25 pin D-Sub connector has become the standard in the recording studio industry, by companies such as Digidesign, for multi-channel analog audio and AES Digital audio. Digidesign is an American Digital audio technology company It was founded in 1984 by Peter Gotcher and Evan Brooks
The D-sub connector family is now in decline for general usage in the computer industry, for several reasons: cost, size, and lack of flexibility. For portable devices such as PDAs, MP3 players or mobile phones, the D-sub connector is usually too large to fit. Many laptop computers, where weight and size are crucial, no longer include D-subs. Even small form factor desktop PCs may find D-sub connectors too large for their value.
Because of the relatively complex shapes and assembly, especially the shaped metal D shield, and screws and nuts for physical securing, D-sub connectors are now quite expensive compared to other common connectors, which are mostly simpler. In the retail PC world where margins are very thin, these connectors are a natural target for removal.
The physical design is not friendly to plug-and-play applications. Thin metal pins, especially in higher-density connectors, are easily bent or broken, especially when frequently plugged in "blind" behind equipment. Although ESD and EMI resistant D-sub connectors exist, the fundamental design was never intended to protect from electrostatic discharge or electromagnetic interference or facilitate very high frequency interconnections. Electrostatic discharge ( ESD) is the sudden and momentary Electric current that flows between two objects at different Electrical potentials The term is
For video purposes, the DE15HD connector is being slowly replaced by DVI and HDMI connectors, although this transition is proceeding more slowly, since many analog CRT monitors are still in use and the digital DVI connector is not useful for those. The High-Definition Multimedia Interface ( HDMI) is a compact audio/video connector interface for transmitting uncompressed digital streams
For the majority of other consumer applications, D-sub serial and parallel connectors have been replaced by IEEE 1394 (FireWire), SATA, USB or Ethernet connections. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently The 8 Position 8 Contact (8P8C modular plugs and sockets are communications connectors
See also
Notes and references
- ^ Are D Subs from all manufactures compatible? — reply in the FAQ section of the Cannon company web
- ^ ITT Cannon 90° PCB Selection Guide, accessed at RS Components website on 2007-09-10
External links
- Ishmael Stefanov-Wagner's web page on D-Subminiature Nomenclature
- A list of common computer connectors, including most D-sub
- Devices with DE-9 connectors
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