D-subminiature
Encyclopedia
Electrical connector
An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or...
. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smaller connectors used on computer systems.
Description, nomenclature, and variants
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
. 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 plug also may have screws on either side of the shield that fasten into holes in the socket (although sometimes the screws are on the socket: see the DE9 pictured to the left). When screened cables are used, the shields are connected to the overall screens of the cables. This creates an electrically continuous screen covering the whole cable and connector system.
The D-sub series of connectors was invented by ITT Cannon, part of ITT Corporation
ITT Corporation
ITT Corporation is a global diversified manufacturing company based in the United States. ITT participates in global markets including water and fluids management, defense and security, and motion and flow control...
, in 1952. Cannon's part-numbering system uses D as the prefix for the whole series, followed by one of A, B, C, D, or E denoting the shell size, followed by the number of pins or sockets, followed by either P (plug) or S (socket) denoting the gender
Gender of connectors and fasteners
In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female...
of the part. Each shell size usually (see below for exceptions) corresponds to a certain number of pins or sockets: A with 15, B with 25, C with 37, D with 50, and E with 9. For example, DB25 denotes a D-sub with a 25-position shell size and a 25-position contact configuration. The contacts in either row of these connectors are spaced 326/3000 of an inch apart, or approximately 0.109 inches (2.77 mm), and the rows are spaced 0.112 inches (2.84 mm) apart (the pins in the two rows are offset by half the distance between adjacent contacts in a row). The suffixes M and F (for male and female) are sometimes used instead of the original P and S.
This naming pattern is not always followed, however. Because personal computers first used DB25 connectors for their serial
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
and parallel
Parallel port
A parallel port is a type of interface found on computers for connecting various peripherals. In computing, a parallel port is a parallel communication physical interface. It is also known as a printer port or Centronics port...
ports, when the PC serial port began to use 9-pin connectors, they were often labeled as DB9 instead of DE9 connectors, due to an ignorance of the fact that B represented a shell size. It is now common to see DE9 connectors sold as DB9 connectors. DB9 nearly always refers to a 9-pin connector with an E size shell. The non-standard 23-pin D-sub connectors for external floppy drives and video output on most of the Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
computers are usually labeled DB23, even though their shell size is two pins smaller than ordinary DB sockets.
There are now D-sub connectors which have the original shell sizes, but more pins, and their names follow the same pattern. For example, the DE15, usually found in VGA
VGA connector
A Video Graphics Array connector is a three-row 15-pin DE-15 connector. The 15-pin VGA connector is found on many video cards, computer monitors, and some high definition television sets...
cables, has 15 pins in three rows, all surrounded by an E size shell. The pins are spaced at 0.09 inch (0.2286 cm) horizontally and 0.078 inch (0.19812 cm) vertically.) The other connectors with the same pin spacing are the DE15, DA26, DB44, DC62, and DD78. Reflecting the same confusion of the letters DB with just D as mentioned above, these connectors are also often called DB15HD (or even DB15 or HD15), DB26HD, DB44HD, DB62HD, and DB78HD connectors, respectively, where HD stands for "high density". They all have three rows of pins, except the DD78, which has four. The "double density" series of D-sub connectors features even denser arrangements and consists of the DE19, DA31, DB52, DC79, and DD100. These each have four rows of pins.
Cannon also produced "hybrid" D-subs with larger contacts in place of some of the normal contacts that could be used for high-current, high-voltage, or co-axial inserts. The DB13W3
DB13W3
DB13W3 is a particular style of D-subminiature connector commonly used as an analog video interface connector that was used primarily on Sun Microsystems, Silicon Graphics and IBM RISC workstations, as well as some displays from Apple Computer, NeXT Computer and Intergraph Corporation...
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. Hybrid D-subs are currently being manufactured in a broad range of configurations by other companies, including Amphenol
Amphenol
Amphenol Corporation is a major producer of electronic and fiber optic connectors, cable and interconnect systems such as Coaxial cables. Amphenol is a portmanteau from the corporation's original name, American Phenolic Corp....
, Conec, Teledyne Reynolds, Assmann Electronics, Norcomp, Cinch
Cinch
Cinch may refer to:*A girth *A belay device for sport climbing*RCA jack, which is sometimes known as a CINCH/AV connector*Cinch , an American card game in the All Fours family, related to Pitch / Setup and Pedro...
, 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
, and Tyco
Tyco
Tyco may refer to:* Tyco International, a diversified industrial conglomerate* Tyco Electronics, a former segment of Tyco International* Tyco Toys, a division of Mattel...
. Some variants have current ratings up to 40A or operating voltages as high as 13,500V; others are waterproof and meet IP67 standards.
A smaller type of connector derived from the D-sub is called the microminiature D, or micro-D, which is a trademark of ITT Cannon. It is about half the length of a D-sub.
There is yet another similar family of connectors that is easy to confuse with the D-sub family. These connectors have names like HD50 and HD68, and have a D-shaped shell that is about half the width of a DB25. They are common in SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
attachments.
The original D-sub connectors are now defined by an international standard, IEC 60807-3 / DIN
Din
DIN or Din or din can have several meanings:* A din is a loud noise.* Dīn, an Arabic term meaning "religion" or "way of life".* Din is one of the ten aspects of the Ein Sof in Kabbalah ....
41652. The United States military also maintains another specification for D-subminiature connectors, the MIL-DTL-24308 standard.
Typical applications
Communications ports
The widest application of D-subs is for RS-232RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
serial communications, though the standard did not make this connector mandatory. RS-232 devices originally used the DB25, but for many applications the less common signals were omitted, allowing a DE9 to be used. The standard specifies a male connector for terminal equipment and a female connector for modems, but many variations exist. IBM PC-compatible computers tend to have male connectors at the device and female connectors at the modems. Early Apple Macintosh models used DE9 connectors for RS-422 serial interfaces (which can operate as RS-232). Later Macintosh models use 8-pin miniature DIN connectors instead.
On PCs, 25-pin and (beginning with the IBM-PC/AT) 9-pin plugs are used for the RS-232
RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
serial ports; 25-pin sockets are used for the parallel printer ports (instead of the Centronics
IEEE 1284
IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices.-History:In the 1970s, Centronics developed the now-familiar printer parallel port that soon became a de facto standard...
socket found on the printer itself).
Many uninterruptible power supply
Uninterruptible power supply
An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...
units have a DE9F connector on them in order to signal
Signal (computing)
A signal is a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. Essentially it is an asynchronous notification sent to a process in order to notify it of an event that occurred. When a signal is sent to a process, the operating system...
to the attached computer via an RS-232 interface. 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.
Network ports
DE9 connectors were used for some token ring networks as well as other computer networkComputer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
s.
The Attachment Unit Interface
Attachment Unit Interface
An Attachment Unit Interface is a 15 pin connection that provides a path between a node's Ethernet interface and the Medium Attachment Unit , sometimes known as a transceiver. It is the part of the IEEE Ethernet standard located between the Media Access Control , and the MAU...
s that were used with 10BASE5
10BASE5
10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding...
"thick net" in the 1980s and 1990s used DA15 connectors for connectivity between the Medium Attachment Unit
Medium Attachment Unit
A Medium Attachment Unit is a transceiver which converts signals on an Ethernet cable to and from Attachment Unit Interface signals.On original 10BASE5 Ethernet, the MAU was typically clamped to the Ethernet cable...
s and (Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
) network interface cards, albeit with a sliding latch to lock the connectors together instead of the usual hex studs with threaded holes. (The sliding latch was intended to be quicker to engage and disengage and to work in places where jack screws could not be used for reasons of component shape.
Computer video output
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
personal computer may be a video display output such as MDA
Monochrome Display Adapter
The Monochrome Display Adapter introduced in 1981 was IBM's standard video display card and computer display standard for the PC. The MDA did not have any pixel-addressable graphics modes...
, Hercules, CGA
Color Graphics Adapter
The Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....
, or EGA
Enhanced Graphics Adapter
The Enhanced Graphics Adapter is the IBM PC computer display standard specification which is between CGA and VGA in terms of color and space resolution. Introduced in October 1984 by IBM shortly after its new PC/AT, EGA produces a display of 16 simultaneous colors from a palette of 64 at a...
(rarely VGA or others). Even though these all use the same DE9 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
Video Graphics Array
Video Graphics Array refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987, but through its widespread adoption has also come to mean either an analog computer display standard, the 15-pin D-subminiature VGA connector or the 640×480 resolution...
and later) adapters generally replaced these connectors with DE15 high-density
VGA connector
A Video Graphics Array connector is a three-row 15-pin DE-15 connector. The 15-pin VGA connector is found on many video cards, computer monitors, and some high definition television sets...
sockets (though some early VGA devices still used DE9 connectors). DE15 connectors are similar to DE9 connectors (see above).
Many Apple Macintosh models (beginning with the Macintosh II) used DA15 sockets for analogue RGB video out. Just prior to this, the Apple IIgs
Apple IIGS
The Apple , the fifth and most powerful model in the Apple II series of personal computers produced by Apple Computer. The "GS" in the name stands for Graphics and Sound, referring to its enhanced graphics and sound capabilities, both of which greatly surpassed previous models of the line...
used the same connector for the same purpose, but in a non-compatible way. A digital (and thus also incompatible) RGB adapter for the Apple IIe also used a DA15F. And the Apple IIc
Apple IIc
The Apple IIc, the fourth model in the Apple II series of personal computers, was Apple Computer’s first endeavor to produce a portable computer. The end result was a notebook-sized version of the Apple II that could be transported from place to place...
used a DA15F for an auxiliary video port which was not RGB, but provided the necessary signals to derive RGB.
Game controller ports
Starting in the late 1970s the Atari 2600Atari 2600
The Atari 2600 is a video game console released in October 1977 by Atari, Inc. It is credited with popularizing the use of microprocessor-based hardware and cartridges containing game code, instead of having non-microprocessor dedicated hardware with all games built in...
game console used DE9 connectors without the pair of fastening screws (male on the system, female on the controller) for its game controller
Game controller
A game controller is a device used with games or entertainment systems used to control a playable character or object, or otherwise provide input in a computer game. A controller is typically connected to a game console or computer by means of a wire, cord or nowadays, by means of wireless connection...
connectors. In the years following, various video game consoles and home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
s adopted the connector for their own game ports, though they were not all interoperable. The common wirings supported digital connections for up, down, left, and right buttons along with one or two others. Some systems supported connecting a pair of analog potentiometers, or paddles
Paddle (game controller)
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 along one axis of the video screen...
, and on some computers a computer mouse or a light pen
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
was also supported via the game port. Like joystick
Joystick
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. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
s, these devices were not typically interchangeable between different systems.
Systems utilizing the DE9 connector for their game port included the Atari
Atari
Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
8-bit and ST lines; the Commodore
Commodore International
Commodore is the commonly used name for Commodore Business Machines , the U.S.-based home computer manufacturer and electronics manufacturer headquartered in West Chester, Pennsylvania, which also housed Commodore's corporate parent company, Commodore International Limited...
VIC-20, 64, 128, and Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
; the Amstrad CPC
Amstrad CPC
The Amstrad CPC is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Sinclair ZX Spectrum, where it successfully established itself primarily in the United Kingdom,...
(which employed daisy-chain
Daisy chain (electrical engineering)
In electrical and electronic engineering a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring...
ing when connecting two Amstrad-specific joysticks); the MSX
MSX
MSX was the name of a standardized home computer architecture in the 1980s conceived by Kazuhiko Nishi, then Vice-president at Microsoft Japan and Director at ASCII Corporation...
, Sharp X68000
Sharp X68000
The Sharp X68000, often referred to as the X68k, is a home computer released only in Japan by the Sharp Corporation. The first model was released in 1987, with a 10 MHz Motorola 68000 CPU, 1 MB of RAM and no hard drive; the last model was released in 1993 with a 25 MHz Motorola 68030...
, and FM-Towns, predominantly used in Japan; the Sega Master System
Sega Master System
The is a third-generation video game console that was manufactured and released by Sega in 1985 in Japan , 1986 in North America and 1987 in Europe....
and Sega Genesis; and the Panasonic 3DO. The Sinclair ZX Spectrum
ZX Spectrum
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...
lacked a built-in joystick connector of any kind but aftermarket interfaces provided the ability to connect DE9 joysticks.
Many Apple II computers also used DE9 connectors for joysticks, but they had a female port on the computer and a male on the controller, used analog rather than digital sticks, and the pin-out was completely unlike that used on the aforementioned systems. DE9 connectors were not used for game ports on the Apple Macintosh, Apple III
Apple III
The Apple III is a business-oriented personal computer produced and released by Apple Computer that was intended as the successor to the Apple II series, but largely considered a failure in the market. Development work on the Apple III started in late 1978 under the guidance of Dr. Wendell Sander...
, IBM PC
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
systems, or most newer game consoles.
DA15S connectors are used for PC joystick connectors, where each DA15 connector supports two joysticks each with two analog axes and two buttons. In other words, one DA15S "game adapter" connector has 4 analog potentiometer inputs and 4 digital switch inputs. This interface is strictly input-only, though it does provide +5V DC power. Some joysticks with more than two axes and/or more than two buttons use the signals designated for both joysticks. Conversely, Y-adapter cables are available that allow two separate joysticks to be connected to a single DA15 game adapter port; if a joystick connected to one of these Y-adapters has more than two axes or buttons, only the first two of each will work.
The IBM DA15 PC game connector has been modified to add a (usually MPU-401
MPU-401
The MPU-401, where MPU stands for MIDI Processing Unit, was an important but now obsolete interface for connecting MIDI-equipped electronic music hardware to Personal Computers...
compatible) MIDI interface, and this is often implemented in the game connectors on third-party sound cards, for example the Sound Blaster
Sound Blaster
The Sound Blaster family of sound cards was the de facto standard for consumer audio on the IBM PC compatible system platform, until the widespread transition to Microsoft Windows 95, which standardized the programming interface at application level , and the evolution in PC design led to onboard...
line from Creative Labs. The "standard" straight game adapter connector (introduced by IBM) has three ground pins and four +5V power pins, and the MIDI adaptation replaces one of the grounds and one of the +5V pins, both on the bottom row of pins, with MIDI In and MIDI Out signal pins. (There is no MIDI Thru provided.) Creative Labs introduced this adaptation.
Other
25-pin sockets on Macintosh computers are typically SCSISCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
connectors (again in contrast to the Centronics C50 connector typically found on the peripheral), while older Sun
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
hardware uses DD50 connectors for FastSCSI equipment.
The complete range of D-sub connectors also includes DA15s (one row of 7 and one of 8), DC37s (one row of 18 and one of 19), and DD50s (two rows of 17 and one of 16); these are often used in industrial products, the 15-way version being commonly used on rotary
Rotary encoder
A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analog or digital code. The output of incremental encoders provides information about the motion of the shaft which is typically further processed...
and linear encoders
Linear encoder
A linear encoder is a sensor, transducer or readhead paired with a scale that encodes position. The sensor reads the scale in order to convert the encoded position into an analog or digital signal, which can then be decoded into position by a digital readout or motion controller.The encoder can be...
.
The early Macintosh and late Apple II
Apple II
The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
computers used an obscure 19-pin D-sub for connecting to external floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
drives. The Commodore Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
used an equally unusual 23-pin version for both its video output and connection to an external floppy disk drive.
TASCAM
TASCAM
TASCAM is the professional audio division of TEAC Corporation, headquartered in Montebello, California. Tascam is credited as the inventor of the Portastudio, the first cassette-based multi-track home studio recorders. Tascam also introduced the first low-cost mass produced multitrack recorders...
used DB25 connectors
D-subminiature (Professional Audio)
D-subminiature connectors are used to carry balanced analog or digital audio on many multichannel professional audio equipment, where the use of XLR connectors is impractical, for example due to space constraints....
for their multi-track recording audio equipment (TDIF), and Logitek Audio later did the same for its broadcast consoles, though with different pinout
Pinout
In electronics, a pinout is a cross-reference between the contacts, or pins, of an electrical connector or electronic component, and their functions.- Purpose :...
s. Roland
Roland Corporation
is a Japanese manufacturer of electronic musical instruments, electronic equipment and software. It was founded by Ikutaro Kakehashi in Osaka on April 18, 1972, with ¥33 million in capital. In 2005 Roland's headquarters relocated to Hamamatsu in Shizuoka Prefecture. Today it has factories in Japan,...
used DB25 connectors
D-subminiature (Professional Audio)
D-subminiature connectors are used to carry balanced analog or digital audio on many multichannel professional audio equipment, where the use of XLR connectors is impractical, for example due to space constraints....
for their multi-track recording audio equipment (R-BUS). A few patch panel
Patch panel
A patch panel or patch bay is a panel, typically rackmounted, that houses cable connections. One typically shorter patch cable will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable...
s have been made which have the DB25 connectors on the back with phone jacks (or even TRS
TRS connector
A TRS connector is a common family of connector typically used for analog signals including audio. It is cylindrical in shape, typically with three contacts, although sometimes with two or four . It is also called an audio jack, phone jack, phone plug, and jack plug...
jacks) on the front, however these are normally wired for TASCAM, which is more common outside of broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
.
In broadcast and professional video, "parallel digital" is a digital video
Digital video
Digital video is a type of digital recording system that works by using a digital rather than an analog video signal.The terms camera, video camera, and camcorder are used interchangeably in this article.- History :...
interface that uses DB25 connectors, per the SMPTE 274M specification adopted in the late 1990s. The more common SMPTE 259M
SMPTE 259M
SMPTE 259M is a standard published by SMPTE which "... describes a 10-bit serial digital interface operating at 143/270/360 Mb/s." The goal of SMPTE 259M is to define a Serial Digital Interface , called SDI or SD-SDI....
"serial digital interface
Serial Digital Interface
Serial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...
" (SDI
Serial Digital Interface
Serial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...
) uses BNC connector
BNC connector
The BNC connector ' is a common type of RF connector used for coaxial cable. It is used with radio, television, and other radio-frequency electronic equipment, test instruments, video signals, and was once a popular computer network connector. BNC connectors are made to match the characteristic...
s for digital video signal transfer.
Wire-contact attachment types
- Solder-bucket (or solder-cup) contacts have a cavity into which the stripped wire is inserted and hand-soldered.
- Insulation displacementInsulation-displacement connectorAn Insulation-displacement connector, insulation-displacement technology/termination or insulation-piercing connector is an electrical connector designed to be connected to the conductor of an insulated wire or cable by a connection process which forces a selectively sharpened blade or blades...
contacts (IDCs) allow a ribbon cableRibbon cableA ribbon cable is a cable with many conducting wires running parallel to each other on the same flat plane. As a result the cable is wide and flat. Its name comes from the resemblance of the cable to a piece of ribbon.Ribbon cables are usually seen for internal peripherals in computers, such as...
to be forced onto sharp tines on the back of the contacts; this action pierces the insulation of all the wires simultaneously. This is a very quick means of assembly whether done by hand or automatically. - 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 the cavity 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 by inserting a special tool into the rear of the connector.
- PCB pins are soldered directly to a printed circuit boardPrinted circuit boardA printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
and not to a wire. 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. - Wire wrapWire wrapWire wrap is a technology used to assemble electronics. It is a method to construct circuit boards without having to make a printed circuit board. Wires can be wrapped by hand or by machine, and can be hand-modified afterwards. It was popular for large-scale manufacturing in the 60s and early 70s,...
connections are made by wrapping solid wire around a square post with a wire wrap tool. This type of connection is usually used in prototyping.
Usage
The 25-pin D-sub connector is occasionally used in recording studios for multi-channel analog audio and AES digital audio.The D-sub connector family is now in decline for general usage in the computer industry, due to size and cost. For portable devices such as PDA
PDA
A PDA is most commonly a Personal digital assistant, also known as a Personal data assistant, a mobile electronic device.PDA may also refer to:In science, medicine and technology:...
s, MP3 players or mobile phones, the D-sub connector is usually too large to fit. In the laptop computer sector, where weight and size are crucial, many models no longer include D-subs. Even small form factor desktop PCs may find D-sub connectors too large for their value.
Because of its relative complexity (the D-shaped metal shield, the screws and nuts), D-sub connectors are now quite expensive compared to other, mostly simpler, common connectors. In the retail PC world where margins are very thin, these connectors are a natural target for removal.
The physical design of D-sub connectors is ill-suited for consumer plug-and-play applications. Thin metal pins, especially in higher-density connectors, are easily bent or broken, particularly if frequently plugged in by touch behind equipment. The need to tighten screws for a secure connection is cumbersome. Although ESD
Electrostatic discharge
Electrostatic discharge is a serious issue in solid state electronics, such as integrated circuits. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide...
- and EMI
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
-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.
For video purposes, the DE15HD connector is in the process of being replaced by DVI
Digital Visual Interface
The Digital Visual Interface is a video interface standard covering the transmission of video between a source device and a display device. The DVI standard has achieved widespread acceptance in the PC industry, both in desktop PCs and monitors...
and HDMI
HDMI
HDMI is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA...
connectors. A notable exception to this replacement is on the many analog CRT monitors still in use: the analog version of the DVI connector is similar in price and more complex than the D-sub, so the shift away from D-subs is slow in this case. For the majority of other consumer applications, D-sub serial and parallel connectors have been replaced by the physically much simpler and cheaper IEEE 1394 (FireWire), SATA
Serial ATA
Serial ATA is a computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives...
, USB, or modular connector
Modular connector
Modular connector is the name given to a family of electrical connectors originally used in telephone wiring and now used for many other purposes. Many applications that originally used a bulkier, more expensive connector have now migrated to modular connectors...
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See also
- Gender of connectors and fastenersGender of connectors and fastenersIn electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female...
- RS-232 Technical Manual
- Micro ribbonMicro ribbonThe micro ribbon or miniature ribbon connector is a common type of electrical connector used particularly in computer and telecommunications applications. Popularly referred to as a Centronics connector due to the widely used Centronics parallel interface, it is also known as a Telco, Amphenol,...
- MMJModified Modular JackThe DECconnect Modified Modular Jack is a variation of the 6P6C modular connector and was developed by Digital Equipment Corporation. The main difference from the conventional modular connector is that the hook is toward the side instead of the center of the plug, making it impossible to insert a...
- Game portGame portThe game port is a device port found on IBM PC compatible systems throughout the 1980s and 1990s. It was the traditional connector for joystick input devices until superseded by USB in the 21st century....