Pogo pin

A Pogo pin is a device used in electronics to establish a (usually temporary) connection between two printed circuit boards. Named by analogy with the pogo stick toy, the pogo pin usually takes the form of a slender cylinder containing two sharp, spring-loaded pins. Pressed between two electronic circuits, the sharp points at each end of the pogo pin make secure contacts with the two circuits and thereby connect them together.

Although often used as a generic name, Pogo is a registered trademark of Everett Charles Technologies (ECT). ECT and its subsidiaries have been manufacturing Pogo pins for over forty years.

Pogo pins are usually arranged in a dense array, connecting together many individual nodes of the two circuit boards. They are very commonly found in automatic test equipment in the form of a bed of nails, where they facilitate the rapid, reliable connection of the devices under test (DUTs). In one extremely high-density configuration, the array takes the form of a ring containing hundreds or thousands of individual pogo pins; this device is sometimes referred to as a pogo tower.

They can also be used to establish more permanent connections, for example, in the Cray 2 computer.

When used in the highest-performance applications, pogo pins must be very carefully designed to allow not only high reliability across many mating/unmating cycles but also high-fidelity transmission of the electrical signals. The pins themselves must be hard, yet plated with a substance (such as gold) that provides for reliable contact. Within the body of the pogo pin, the pins must make good electrical contact with the body lest the spring carry the signal (along with the undesirable inductance that the spring represents). The design of pogo pins to be used in matched-impedance circuits is especially challenging; to maintain the correct characteristic impedance, pogo pins are sometimes arranged with one signal-carrying pin surrounded by four, five, or six grounded pins.

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