Edge connector

Anedge connectoris the portion of aprinted circuit board(PCB) consisting oftracesleading to the edge of the board that are intended to plug into a matchingsocket.The edge connector is a money-saving device because it only requires a single discretefemale connector(the male connector is formed out of the edge of the PCB), and they also tend to be fairly robust and durable. They are commonly used in computers forexpansion slotsfor peripheral cards, such asPCI,PCI Express,andAGPcards.

Two 44-pin edge connector sockets (blue objects) and matching circuit board. The Edge connector is 3.5 in (89 mm) long, with 22 contacts on each side

Edge connector forPCIex4

Socket design

Edge connector sockets consist of a plastic "box" open on one side, with pins on one or both sides of the longer edges, sprung to push into the middle of the open center. Connectors are oftenkeyedto ensure the correctpolarity,and may contain bumps or notches both for polarity and to ensure that the wrong type of device is not inserted. The socket's width is chosen to fit to the thickness of the connecting PCB.

The opposite side of the socket is often aninsulation-piercing connectorwhich is clamped onto aribbon cable.Alternatively, the other side may besolderedto amotherboardordaughtercard.

Uses

An openedGame Boycartridge with edge connector on bottom

Edge connectors are commonly used inpersonal computersfor connectingexpansion cardsandcomputer memoryto thesystem bus.Example expansion peripheral technologies which use edge connectors includePCI,PCI Express,andAGP.Slot 1andSlot Aalso used edge connectors; theprocessorbeing mounted on a card with an edge connector, instead of directly to the motherboard as before and since.

IBM PCsused edge connector sockets attached to ribbon cables to connect 5.25 "floppy disk drives.3.5 "drives use a pin connector instead.

Video game cartridgestypically take the form of a PCB with an edge connector: the socket is located within the console itself. TheNintendo Entertainment Systemwas unusual in that it was designed to use azero insertion forceedge connector:instead of the user forcing the cartridge into the socket directly, the cartridge was first placed in a bay and then mechanically lowered into position.

Starting with theAmiga 1000in 1985, various Amiga models used the 86-pin Zorro I edge connector, which was later reshaped into the internal 100-pinZorro IIslot on theAmiga 2000and later upmarket models.

See also

• Pin headerconnector
• Insulation-displacement connector