Chip Talk - Historical

  ACRONYMS and Vocabulary used and understood by the industry-at-large. This is a working list that was started in 1964.

Please send in your old words & acronyms with definitions to aid researchers in their quest for understanding.

A/D Converter or ADC

Analog-to-digital converter. A device to convert variable or analog signals to digital representation

Access Time

The time interval between the instant that data is called from or delivered to a storage device (memory) and the instant that requested retrieval or storage is complete


A prescribed set of well defined rules for the solution of a problem. Algorithms are implemented on a computer by a stored sequence of instructions.


The arranging of the mask and wafer in correct positions, one with respect to the other. Special alignment patterns are normally part of the mask.


Indicates continuous, non-digital representation of phenomena. An analog voltage, for example, may take any value.


A system of numbers using 2 as a base in contrast to the decimal system which uses 10 as a base. The binary system requires only two symbols...0 and 1.

Bipolar or BiPolar

refers to transistors formed with two (N- and P- type) semiconductor types. (N=negative; P=positive)


A binary digit. A bit is the smallest unit of storage in a digital computer and is used to represent one of two digits in the binary number system.

Buried Layer

A low-resistivity diffused region placed under the collector to reduce its series resistance.


A circuit or group of circuits which provide a communication path between two or more devices.


A set of contiguous binary bits, usually eight (8), which operate on as a unit. A byte can also be a sub-set of a computer word.


Construction Analysis


Consultative Committee for International Telephony and Telegraphy


A region of surface conduction opposite in type from that of the bulk doping of an FET transistor.


A single square or rectangular piece of semiconductor material into which a specific electrical circuit has been fabricated. Plural is dice. Also called a die.


Complementary Metal Oxide Semiconductor. A logic family made by combining N- channel and P- channel MOS transistors.


Also called a differential comparator. A circuit that compares two analog inputs and produces a 1 or 0 logic level output, depending on which voltage input is more positive.


Central Processing Unit. The part of the computer that fetches, decodes, and executes program instructions and maintains status of results.

D/A Converter or DAC

A device to convert digital representation into an analog voltage or current level.


A general term used to denote any or all facts, numbers, letters, and symbols. It connotes basic elements of information which can be processed or produced by a computer.

Depletion Device

A type of MOSFET which is "on"

Development System

Microcomputer system complete with peripherals, memory and software, used to write, compile, run and debug application programs for one or more target microprocessors.


A single square or rectangular piece of semiconductor material into which a specific electrical circuit has been fabricated. Plural is dice. Also called a chip.


A method of doping or modifying the characteristics of semiconductor material by "baking" wafers of the base semiconductor material in furnaces with controlled atmospheres of impurity materials.


Dual-In-line Package. The most common type of IC package, circuit leads or pins extend symmetrically outward and downward from opposite sides of the rectangular package body.


A semiconductor device containing only one active device, such as a transistor or a diode.


An impurity that can make a semiconductor N-type by donating extra "free" electrons to the conduction band. The free electrons are carriers of negative charge.


The introduction of an impurity into a semiconductor to modify its electrical properties by creating a concentration of N or P carriers.

Dynamic RAM

A type of semiconductor memory in which the presence or absence of a capacitive charge represents the state of a binary storage element. The charge must be periodically refreshed.


Electrically Alterable ROM, a read-only memory whose contents may be altered on rare occasions through electrical stimuli.


Emitter Coupled Logic. A form of current-mode logic in which the output is available from an emitter-follower output stage.


Electrically Erasable Read Only Memory

Enhancement Device

A type of MOSFET which requires a control signal input to turn on the device. This device is "off" when no input signal is present.

Epitaxial Layer

A deposited layer of material having the same crystallographic characteristics as the substrate material.


Erasable PROM, similar to ROM, but enables the user to erase stored information and replace it with new information, when necessary. Most EPROMs are erased through exposure to ultra-violet light.


Failure Analysis


Field Effect Transistor


Software in hardware form, referring specifically to microcode in ROM.

Flat Pack

An IC package which has leads extending from the package in the same plane as the package so that leads can be spot welded to terminals on a substrate or soldered to a printed circuit board.


An electrical circuit having two stable states, on or off. The basic component of a logic or memory circuit.


Field Programmable Logic Array, a PLA can be programmed by the user.


The basic digital logic element ... where the binary value of the output depends on the values of the inputs.

Gate Equivalent

The basic unit of measure for digital circuit complexity, based on the number of elementary logic gates that would have to be interconnected to form the same circuit function.


The protective coating placed on the entire die surface, usually silicon dioxide or silicon nitride. Also called passivation.


High-performance Metal Oxide Semiconductor


The absence of a valance electron in a semiconductor crystal. The movement of a hole is equivalent to the movement of a positive charge.

Hybrid Circuit

Any combination of two or more of the following in ONE package: active substrate integrated circuit; passive substrate integrated circuit; discrete component.


Input/Output relating to the equipment or method used for transmitting information into and out of a computer.


Integrated Circuit -- a semiconductor die containing multiple elements that act together to form the complete device circuit.


Institute of Electrical and Electronics Engineers


Integrated Injection Logic, a bipolar structure characterized by an integrated PNP load device and inverted operation of the NPN logic transistor.

Ion Implantation

Introduction into a semiconductor of selected impurities via high voltage ion bombardment to achieve desired electrical properties in selected regions.


The boundary between a P region and an N region in a semiconductor substrate.


Light Emitting Diode, a semiconductor device that emits light whenever current passes through it.

Linear IC

An analog integrated circuit, as opposed to a digital integrated circuit.


Low-power Schottky Transistor Transistor Logic, the power dissipation of LS TTL is typically 1/5th that of conventional TTL.


Large Scale Integration-- LSI devices contain 100 or more gate equivalents or other circuitry of similar complexity.

Majority Carrier

The mobile charge carrier (hole or electron) that predominates in a semiconductor material.


A patterned screen, usually of glass, used to expose selected areas of a semiconductor (that has been covered with a photoresist) to a light source that causes polymerization.


Metalic Schottky Field Effect Transistor, a field effect transistor whose gate structure consists of a metalic Schottky barrier.


A set of control functions performed by the instruction decoding and execution logic of a CPU or microprocessor which defines the instruction repertoire of that computer.


A microprocessor complete with stored program memory (read only memory ROM), random access memory (RAM), and Input/Output (I/O) logic. If all functions are on the same chip, this is sometimes called a microcontroller. Microcomputers are capable of performing useful work without additional supporting logic.


If all functions, ROM, RAM, I/O are on the same chip, this is sometimes called a microcontroller..


Microscopically small components or circuits made by means of photolithography techniques.


Synonymous with micrometer: one millionth of a meter.


The basic arithmetic of a computer’s, Central Processing Unit (CPU)


One thousandth of an inch, equal to 25.4 microns.

Monolithic Device

A device whose circuitry is completely contained on a single die or chip


Metal Oxide Semiconductor, devices using FETs in which current flow through a channel of N- or P- type semiconductor material is controlled by the electric field around a gate structure. MOSFETs are unipolar devices characterized by extremely high input resistance.


Metal Oxide Semiconductor Field Effect Transistor


Medium Scale Integration, ICs containing ten or more gate equivalents but less than 100.

N-Channel MOS

A type of MOSFET using electrons to conduct current in the semiconductor channel. The channel has a predominantly negative charge.

Op Amp

Operational Amplifier, a general purpose IC used as a basic building block for implementation of linear functions.

Optical Isolator

A circuit-isolation device consisting of an LED and a photodiode or photo transistor in close proximity. Current through the LED causes internal light emission, which current flow in the (isolated) photo transistor.

P-Channel MOS

A type of MOSFET using holes to conduct current in the semiconductor channel. The channel has a predominantly positive charge.


Purchase Order


Product Analysis


The protective coating placed on the entire die surface, usually silicon dioxide or silicon nitride. Also called glassivation.


Pulse Code Modulation, digital transmission of analog signals by sending periodic binary-coded samples of the signal value.


Product Evaluation


Light-sensitive material deposited as a uniform thin film on a wafer or substrate. Exposure of specific patterns is performed through masking operations.


(typically) the product being investigated


Programmable Logic Array, a general purpose logic circuit containing an array of logic gates which can be connected (programmed) to perform various functions.

PLL or PL2

Phase-Lock-Loop, a circuit that compares the phase difference between a reference frequency and a voltage-controlled oscillator, whereby the oscillator’s frequency is changed by an error voltage until its frequency coincides with the reference.


A term used to describe electrical testing that employs very finely-tipped probes applied sequentially to each of the finished dice on a wafer.


Programmable Read Only Memory, a read-only memory which can be programmed after manufacture by external equipment. Typically, PROMs utilize fusible links which may be burned open to produce a logic bit in a specific location.


A set of rules for the formatting and relative timing between communicating processes.


Rome Air Development Center


Random Access Memory, which stores digital information temporarily and can be changed by the user. It constitutes the basic storage element in a computer. Also called a read/write memory.


(chips which can replace money as the medium of exchange)


Read Only Memory, which permanently stores information used repeatedly such as microcode or characters for electronic display. Unlike RAM, ROM cannot be altered.


A form of TTL logic in which Schottky diodes are used to clamp the transistors out of saturation, effectively eliminating the storage of charge within the transistor ... allowing increased switching speeds.

Schottky TTL

A form of TTL logic in which Schottky diodes are used to clamp the transistors out of saturation, effectively eliminating the storage of charge within the transistor allowing increased switching speeds.


A material with properties of both a conductor and an insulator. Common semiconductors include silicon and (expensive) germanium.

Silicon Gate

A type of MOS in which the gate is made of silicon instead of metal. Faster and denser than metal-gate MOS.


A this disc (not disk) of semiconducting material (usually silicon) on which many separate chips can be fabricated and then cut into individual Ics. Also known as wafer.


Selective Oxidation Complementary Metal Oxide Semiconductor


Silicon-On-Sapphire, a faster MOS technology in which the silicon is grown on a sapphire wafer only where needed. Each device is thus isolated by air or oxide from other devices.


Small Scale Integration, Ics containing fewer than ten logic gates.

Static RAM

A type of Random Access Memory which does not require periodic referesh cycles, as does dynamic RAM.


A classified code name for Cold War-Military Contracts held within ICE which carry classified code numbers (0000 - 4390)


Time Division Multiplex, a method of transmitting several data signals over a single line by assigning each to different time slots.


The input voltage at which the output logic level changes state.


The basic solid-state device used to amplify or switch electrical current.

TTL or T2L

Transistor Transistor Logic


A commonly-used LSI circuit which serves as a universal (asynchronous) serial communication line controller and data interface for a microprocessor.


Transistors with majority current conduction (majority carrier) only, as observed in FETs.


Very Large Scale Integration, these devices are Ics that contain 1,000 or more gate equivalents.


A this disc (not disk) of semiconducting material (usually silicon) on which many separate chips can be fabricated and then cut into individual Ics. Also known as slice.


The arranging of a mask and wafer in correct positions with respect to each other. After alignment, radiation-sensitive photoresist on the wafer is exposed by radiation passing through the non-opaque areas of the mask.


An optical system used in transferring a mask or reticle image to a wafer.

Active Component

A (non-mechanical) circuit component that has gain or switches current flow, such as a diode, transistor, etc.


The property of radiant energy, especially in the visible and UV spectral regions, by which chemical changes are produced.


An impurity that can make a semiconductor P-type by causing the absence of electrons in the conduction band (called "holes"). These "holes" are carriers of positive charge.

Alignment Mark

A reference mark used in the alignment of the several photomask layers required for a single device or circuit.


Advanced Low-power Schottky Transistor Transistor Logic, A fast bipolar logic family with power dissipation about half that of LSTTL.


A set of binary bits processed by the computer as the primary unit of information.

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