Pogo pin
Encyclopedia
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
to establish a (usually temporary) connection between two printed circuit board
Printed circuit board
A 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...
s. Named by analogy with the pogo stick
Pogo stick
A pogo stick is a device for jumping off the ground in a standing position with the aid of a spring, used as a toy or exercise equipment. It consists of a pole with a handle at the top and footrests near the bottom, and a spring located somewhere along the pole...
toy, the pogo pin usually takes the form of a slender cylinder containing two sharp, spring-loaded
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...
pin
Pin
A pin is a device used for fastening objects or material together.Pin may also refer to:* Award pin, a small piece of metal or plastic with a pin attached given as an award for some achievement...
s. 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
Automatic test equipment
Automatic or Automated Test Equipment is any apparatus that performs tests on a device, known as the Device Under Test , using automation to quickly perform measurements and evaluate the test results...
in the form of a bed of nails, where they facilitate the rapid, reliable connection of the devices under test
Device under test
Device under test , also known as unit under test , is a term commonly used to refer to a manufactured product undergoing testing.-In semiconductor testing:...
(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
Signal (electrical engineering)
In the fields of communications, signal processing, and in electrical engineering more generally, a signal is any time-varying or spatial-varying quantity....
. The pins themselves must be hard, yet plated
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...
with a substance (such as gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
) 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
Inductance
In electromagnetism and electronics, inductance is the ability of an inductor to store energy in a magnetic field. Inductors generate an opposing voltage proportional to the rate of change in current in a circuit...
that the spring represents). The design of pogo pins to be used in matched-impedance
Electrical impedance
Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...
circuits is especially challenging; to maintain the correct characteristic impedance
Characteristic impedance
The characteristic impedance or surge impedance of a uniform transmission line, usually written Z_0, is the ratio of the amplitudes of a single pair of voltage and current waves propagating along the line in the absence of reflections. The SI unit of characteristic impedance is the ohm...
, pogo pins are sometimes arranged with one signal-carrying pin surrounded by four, five, or six grounded
Ground (electricity)
In electrical engineering, ground or earth may be the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth....
pins.
Pogo pins and Pogo pin cables are also widely used for in-circuit programming for Microcontrollers.
See also
- Jumper (computing)Jumper (computing)In electronics and particularly computing, a jumper is a short length of conductor used to close a break in or bypass part of an electrical circuit...
, performs similar function but bridges a circuit between two pins - FCT (test)FCT (test)FCT refers to functional test. The functional test is typically performed in the last phase of the production line of a product, as a final quality control. FCT are performed to ensure that the device under test fulfills its functional specifications....
, Functional test - In-circuit testIn-circuit testIn-circuit test is an example of white box testing where an electrical probe tests a populated printed circuit board , checking for shorts, opens, resistance, capacitance, and other basic quantities which will show whether the assembly was correctly fabricated...