Glossary

P

p: (abbreviation) See pico-.
P-cable: A 68-wire cable used for 16-bit SCSI-3 buses. P-cables can be used with Q-cables for 32-bit SCSI-3 buses.
panel mount: (connector) A method of fixing a connector to a board, panel, or frame. The mounted connector is usually the receptacle or female connector. The plug or male connector is usually the removable portion.
parallel circuit: (circuit) A circuit in which two or more loads are connected to a single voltage source, at a common point.
parallel splice: (electrical) A splice wherein two wires are joined together side-by-side, either from the same end of the splice, or from opposite ends of the splice.
parts density: (general) The number of parts per unit volume.
passivation: (process) The stabilization and protection of component surfaces from environments which might induce changes in characteristics. In monolithic integrated circuits this function is achieved by silicon dioxide grown onto the surface of the silicon, or by the deposition of a glass coating.
passive components: (circuit) Components which have no gain characteristics, such as capacitors and resistors.
passive element: (component/electrical) A circuit component with no source of energy (eg, resistor, capacitor, inductor, etc).
passive substrate: (material/component) A support made of insulating material used as a base for the deposition of film components.
Patch Cord: The connecting cord between the terminal device and the drop.
path: (circuit) That portion of a printed circuit pattern which carries current between two pads or between a pad and the terminal area (printed contact, edge pad). See also pad, and terminal area.
pcb: (abbreviation) See printed circuit board.
pcm: (abbreviation/circuit) Pulse code modulation. A scheme by which an analog signal is sampled and converted to a digital signal for transmission.
peaks: (circuit) Momentary high amplitude levels occurring in electronic equipment.
Percent Conductivity: Conductivity of a material expressed as a percentage of that of copper.
peripheral seal: (connector) A design feature which provides an environmental seal between the forward end of plug and forward end of the receptacle even though they are not fully engaged. It generally consists of a piece of rubber fastened around the inner sidewall of the receptacle front opening skirt or around the outer sidewall of the plug engagement section.
permeability: (chemical) – The passage or diffusion (or rate of passage) of a gas, vapor, liquid, or solid through a barrier without physically or chemically affecting it.; (magnetic) – The measure of how much better a given material is than air as a path for magnetic lines of force. Air is assumed to have a permeability of 1.
PGA: (abbreviation) See pin grid array.
phase control: (circuit) A circuit technique for proportional control of an output signal by conduction only during certain phases of an ac line voltage.
phase locked loop: (circuit) In communications, a circuit technique by which a local oscillator is synchronized in phase and frequency with a signal being received.
phase modulation: (circuit) A method of transmission in which the angle of the phase of the carrier wave is varied in accordance with the signal.
phase splitter: (circuit) A circuit which generates – out of an ac input signal – two equal-amplitude outputs, one of which is 180 out of phase with the other (ie one is the other inverted). The dc levels may not be identical.
phenolic: (material) A thermosetting plastic material available in many combinations of phenol and formaldehyde. Often there are fillers added to provide a broad range of physical, electrical, chemical, and molding properties. Commonly used for housings, inserts, and programming system panels.
photodetector: (fiber optic) A device that is sensitive to light and will produce an electric current in its presence.
photoresist: (process) A lightsensitive organic coating that can be selectively deposited to resist the action of the etchant (etching solution) and produce the desired circuit pattern.
pickup value: (voltage, current, or power) (device/circuit) The minimum value which will energize the contacts of a relay.
pico: (prefix) A prefix meaning 10-12, or one trillionth.
pi: (p) filter (component/electrical) A lumped-element filter using, for low pass, two parallel capacitive elements and a series inductive element between them.
pigments: (material) Coloring matter, often in powder form, having a wide range of colors and physical properties.
pigtail: (fiber optic) A source or detector that is permanently joined to a short length of fiber in manufacturing with epoxy enabling the fiber to be brought very close to the semiconductor chip for maximum efficiency.
pin contact: (component) A male type contact, usually designed to mate with a socket or female contact. It is normally connected to the “dead” side of a circuit.
pin grid array: (IC) A ceramic substrate with rows of short round pins extending out the bottom in an x-y or fence array.
planar: (general) – Existing essentially in a single plane.
plastic: (material) High polymeric substances, including both natural and synthetic products, but excluding the rubbers, that are capable of flowing under heat and pressure at one time or another.
plasticizers: (material) Chemical materials incorporated in a plastic to increase its workability during processing, and to impart flexibility and other desirable properties, such as flame retardance and increased electrical insulating properties, to the finished product.
plug: (connector) In coaxial rf connectors the plug is normally the movable portion and is usually attached to a cable or removable subassembly. In shell type multiple-contact connectors the plug usually contains the socket contacts and is mounted on the “hot” (rack) side of the system. Plugs mate with receptacles, jacks, outlets, etc.
polarization: (product feature) That feature of a housing, shell, or insert that permits the mating of plug and receptacle in only one specified alignment. Under certain circumstances, polarization and keying may be combined in a connector design. Mechanical features on mating components to prevent incorrect mating.
polarizing pin: (product feature) A device incorporated in a connector to accomplish polarization.
pole: (device/circuit) Elements of a device that control one path of the circuit; an output terminal of a switching device (eg switch or relay); a combination of mating contacts – normally open, normally closed, or both.
poly: (prefix/general) A prefix meaning many. Thus, polymer means many mers, signifying a repeated structural unit.
polyamide: (material) A compound characterized by more than one amide group. See nylon.
polybutadiene: (material) A family of thermosetting molding compounds offering good physical properties, excellent electrical properties, and outstanding resistance to aqueous interfaces.
polyethylene: (material) A thermoplastic material composed of polymers of ethylene. A variety of types of polyethylene are used in wires and cables in very large amounts. Polyethylene has excellent electrical properties for wire and cable insulation plus superior abrasion and solvent resistance, moisture resistance, lightweight, low brittle point, and durability.
polyimide: (material) A polymer made of imide monomers. Available both for wire insulation in both film form and as a magnet wire enamel. It offers high heat-resistance as well as a strong chemical resistance.
polymer: (material) A compound formed by polymerization which results in the chemical union of monomers or the continued reaction between lower molecular weight polymers.
polymerize: (process) To unite chemically two or more monomers or polymers of the same kind to form a molecule with higher molecular weight.
polypropylene: (material) A plastic similar to polyethylene but is lighter and offers even better heat resistance, tensile strength, abrasion resistance, and lower dielectric constant.
polyurethane: (material) A thermosetting polymer made of a series of organic urethane links. It is primarily of interest as a magnet wire enamel for wires which can be soldered without prior removal of the insulation.
polyvinyl butyral: (material) A thermoplastic material derived from butyraldehyde. Tough, colorless, flexible solid, used in laminates, adhesives, coatings, and crosslinked with ureas, phenolics, and other materials.
polyvinyl chloride: (pvc) (material) Thermoplastic compound composed of vinyl chloride polymers. Blended with other polymers or copolymerized with monomers to give abrasion resistance, heat stability, short molding cycles, and low shrinkage.
positive lock: (product feature) A type of latch or locking mechanism that engages in such a way that the parts cannot be unlocked accidentally. Used to hold die sets in tools, inserts in shells, connectors in mated position, contacts in certain pc board disconnects, etc.
pot: (process) To embed a component in a material within a casing that becomes part of the product, primarily for protection.
potentiometer: (component) A popular term for a variable resistor.
(instrument) A precision instrument used for measuring dc potential (and thereby current or resistance). A null method is used so that no power is transferred to or from the unit under test.
potting: (process) The sealing of a component (eg, the cable end of a multiple-contact connector) with a plastic compound or material – to exclude moisture, prevent short circuits, provide strain relief, etc.
pressure differential: (connector) The difference in pressure between one side of a connector and the other, as in a bulkhead mounting. Or the pressure difference between the inside and outside of a sealed connector.
Primary Insulation: The first layer of non-conductive material applied over a conductor, whose prime function is to act as electrical insulation.
printed circuit edge connector: (connector) A connector designed specifically for making removable and reliable interconnections between the terminal area (edge pads) of a printed circuit board and the external wiring.
printed components: (components) See printed element.
printed element: (component) An element in printed form, such as a printed inductor, resistor, capacitor, or transmission line. Printed elements are formed on printed circuit boards along with connections. Also called printed components.
printing: (process/circuit) The act or art of reproducing a pattern on a surface by any of various processes, such as vapor deposition, photo etching, embossing, diffusion, or screening.
production model: (product) A model in its final mechanical and electrical design form, and manufactured using production tooling and methods.
Propagation Delay: Time required for an electronic digital device, or transmission network to transfer information from its input to its output.
Propagation Delay Time: The time between the application of a digital input waveform and the corresponding change in input waveform. It is measured between reference points on the waveforms. The time is generally different for positive-going and negative-going waveforms.
Propagation, Velocity of: A ratio comparing the speed of a wave (transmission, signal, etc.) with the speed of light in a vacuum. It varies as follows:; Medium Speed, miles per second; Light through space 186,284; Radio through air 142,000; Coaxial cable 133,000
protocol: (computer) A formal set of conventions or rules governing the format, timing, and error control to facilitate message exchanges among electronic equipment.
Prototype: A model suitable for use in the complete evaluation of form, design, and performance.
psi: (abbreviation) Pounds per square inch, normally used for measuring air pressure.
p-type conductivity: (semiconductor) The conductivity associated with holes in a semiconductor, which is equivalent to a positive charge.
p-type semiconductor: (component) An extrinsic semiconductor in which the hole density exceeds the conduction electron density, therefore the majority carriers are holes. The net ionized impurity concentration is the acceptor type.
pull out: (connector) Force required to separate a cable from a connector by pulling them apart. See also contact retention.
pull strength: (property) See bond strength.
pull test: (general) The application of longitudinal stress for the purpose of testing. See also tensile strength.
pulse: (electrical/electronic) A change in the level, over a relatively short period of time, of a signal whose value is normally constant. Example: The voltage level of a point shifts from 0 to +12 volts, with respect to ground, for a period of 2 microseconds. Pulses represent the 1’s and 0’s of digital logic.
pulse broadening: (fiber optic) The spreading or lengthening of a light pulse due to modal or spectral dispersion.
pulse-forming network: (circuit/system) A device to store electricity and release it in pulses at specified time intervals (frequency).
pulse width: (electrical/electronic) The length of time that the pulse voltage is at the transient level. Electronic pulse widths normally are in the millisecond (10-3), microsecond (10-6), or nanosecond (10-9) range. See also pulse.
purple plague: (IC) A gold-to-aluminum combination – at high temperatures – forms a gold-aluminum intermetallic compound. This compound, called purple plague because of its purple color, weakens the bond. On the chip, pads are normally aluminum and when the wire to be bonded is gold, this condition may occur. Plague can be prevented by avoiding processes involving high heat, or by using aluminum-to-aluminum (or even gold-to-gold) junctions.
Put-Up: Packaging of finished wire or cable.
PVC: Polyvinyl Chloride. The material most commonly used for the insulation and jacketing of cable.
pwb: (abbreviation) See printed wiring board and printed wiring.

Glossary

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