Welcome to the electronics glossary in our library!

The following glossary entries were abstracted from the book, Bebop to the Boolean Boogie (An Unconventional Guide to Electronics), with the kind permission of LLH Technology Publishing, Eagle Rock, VA, USA                          ( to return to the main glossary.)

The process of converting an analog signal into a series of digital values.

A notation in which each signal is assigned a unique name; for example, a3, a2, a1, and a0.

A technique for making transistors switch faster by reducing their size. This strategy is known as scaling, because all of the transistors features are typically reduced by the same proportion.

Common name for a circuit diagram.

The process of vibrating two pieces of metal, or metal coated materials, at ultrasonic frequencies to create a friction weld.

Popular name for a channel-less gate array.

Popular name for a channel-less gate array.

An initial value loaded into a linear feedback shift register or random number generator.

A special class of material that can exhibit both conducting and insulating properties.

A transducer that detects a physical quantity and converts it into a form suitable for processing. For example, a microphone is a sensor which detects sound and converts it into a corresponding voltage or current.

A function whose output value depends not only on its current input values, but also on previous input values. That is, the output value depends on a sequence of input values.

Refers to a shift register in which the data is loaded in serially and read out in parallel.

Refers to a shift register in which the data is both loaded in and read out serially.

Base-60 numbering system.

A laser diode constricted at the edge of an integrated circuit's substrate such that, when power is applied, the resulting laser beam is emitted horizontally; that is, parallel to the surface of the substrate.

Amplifying, filtering, or otherwise processing a signal.

A layer carrying tracks in a circuit board, hybrid, or multichip module. See also wiring layer.

Refers to the checksum value from a cyclic-redundancy-check when used in the guided-probe form of functional test.

A guided-probe functional-test technique based on signatures.

The most significant binary digit, or bit, of a signed binary number. If set to a logic 1, this bit represents a negative quantity.

A binary number in which the most-significant bit is used to represent a negative quantity. Thus, a signed binary number can be used to represent both positive and negative values.

Negative numbers in standard arithmetic are typically represented in sign-magnitude form by prefixing the value with a minus sign; for example, ?27. For reasons of efficiency, computers rarely employ the sign-magnitude form. Instead, they use signed binary numbers to represent negative values.

The process of depositing additional metalization on a die's pads to raise them fractionally above the level of the Barrier Layer.

Although a variety of semiconductor materials are available, the most commonly used is silicon and integrated circuits are popularly known as silicon chips, or simply chips.

The program used in compiled cell technology to generate the masks used to create components and interconnections. May also be used to create data-path functions and memory functions.

A printed circuit board with tracks on only one side.

A process in which ultra-fine metal powders weld together at temperatures much lower than those required for larger pieces of the same materials.

Refers to a shift register in which the data is loaded in serially and read out in parallel.

Refers to a shift register in which the data is both loaded in and read out serially.

In the case of high frequency signals, electrons are only conducted on the outer surface, or skin, of a conductor. This phenomenon is known as the skin effect.

Refers to the number of logic gates in a device. By one convention, small-scale integration represents a device containing 1 to 12 gates.

A component whose packaging is designed for use with surface mount technology.

A technique for populating hybrids, multichip modules, and circuit boards, in which packaged components are mounted directly onto the surface of the substrate. A layer of solder paste is screen printed onto the pads and the components are attached by pushing their leads into the paste. When all of the components have been attached, the solder paste is melted using either reflow soldering or vapor-phase soldering.

A technique in which the solder mask is applied in advance of the tin-lead plating. This results in lighter circuit boards because the tin-lead alloy is only used to plate the pads.

A logic function defined by the manufacturer of an application-specific integrated circuit. The function is described in terms of the simple functions provided in the cell library and connections between them. The assignment of cells to basic cells and the routing of the tracks is determined at the same time, and using the same tools, as for the other cells specified by the designer.

Refers to intangible programs, or sequences of instructions, that are executed by hardware.

An alloy of tin and lead with a comparatively low melting point used to join less fusible metals. Typical solder contains 60% tin and 40% lead - increasing the proportion of lead results in a softer solder with a lower melting point, while decreasing the proportion of lead results in a harder solder with a higher melting point. Note that the solder used in a brazing process is of a different type, being a hard solder with a comparatively high melting point composed of an alloy of copper and zinc (brass).

A flipped chip technique in which spheres of solder are formed on the die's pads. The die is flipped and the solder bumps are brought into contact with corresponding pads on the substrate. When all the chips have been mounted on the substrate, the solder bumps are melted using reflow soldering or vapor-phase soldering.

A layer applied to the surface of the substrate that prevents solder from sticking to any metalization except where holes are patterned into the mask.

A technique in which the solder mask is applied in advance of the tin-lead plating. This results in lighter circuit boards because the tin-lead alloy is only used to plate the pads.

Used to refer to the width of the gap between adjacent tracks.

A memory device in which each cell is formed from four or six transistors configured as a latch or a flip-flop. The term static is used because, once a value has been loaded into an SRAM cell, it will remain unchanged until it is explicitly altered or until power is removed from the device.

Refers to the number of logic gates in a device. By one convention, small-scale integration represents a device containing 1 to 12 gates.

An application-specific integrated circuit which, unlike a gate array, does not use the concept of a basic cell and does not have any pre-fabricated components. The manufacturer creates custom masks for every stage of the device's fabrication allowing each logic function to be created using the minimum number of transistors.

The process by which the states in a state machine are assigned to the binary patterns that are to be stored in the state variables.

A graphical representation of the operation of a state machine.

The actual implementation (in hardware or software) of a function that can be considered to consist of a set of states through which it sequences.

A sentence that asserts or denies an attribute about an object or group of objects. For example, "Your face resembles a cabbage."

A tabular representation of the operation of a state machine. Similar to a truth table, but also includes the current state as an input and the next state as an output.

An arc connecting two states in a state diagram.

One of a set of registers whose values represent the current state occupied by a state Static Flex

A memory device in which each cell is formed from four or six transistors configured as a latch or a flip-flop. The term static is used because, once a value has been loaded into an SRAM cell, it will remain unchanged until it is explicitly altered or until power is removed from the device.

A condition in which nothing is changing or happening.

A type of flexible printed circuit which can be manipulated into permanent three-dimensional shapes for applications such as calculators and high-tech cameras which require efficient use of volume and not just area.

A process in which structures on an integrated circuit's substrate are eroded by the flow of electrons in much the same way as land is eroded by a river (also known as electromigration)

Generic name for the base layer of an integrated circuit, hybrid, multichip module, or circuit board. Substrates may be formed from a wide variety of materials, including semiconductors, ceramics, FR4 (fiberglass), glass, sapphire, or diamond depending on the application. Note that the term substrate has traditionally not been widely used in the circuit board world, at least not by the people who manufacture the boards. However, there is an increasing tendency to refer to a circuit board as a substrate by the people who populate the boards. The main reason for this is that circuit boards are often used as substrates in hybrids and multichip modules, and there is a trend towards a standard terminology across all forms of interconnection technology.

A process in which a substrate is first covered with conducting material, then any unwanted material is subsequently removed, or subtracted.

A Boolean equation in which all the minterms corresponding to the lines in the truth table for which the output is a logic 1 are combined using OR operators.

A material with zero resistance to the flow of electric current.

A laser diode constricted on an integrated circuit's substrate such that, when power is applied, the resulting laser beam is emitted directly away from the surface of the substrate.

A component whose packaging is designed for use with surface mount technology.

A technique for populating hybrids, multichip modules, and circuit boards, in which packaged components are mounted directly onto the surface of the substrate. A layer of solder paste is screen printed onto the pads and the components are attached by pushing their leads into the paste. When all of the components have been attached, the solder paste is melted using either reflow soldering or vapor-phase soldering.

A mathematical form in which propositions and their relationships may be represented symbolically using Boolean equations, truth tables, Karnaugh maps, or similar techniques.

(1)A signal whose data is not acknowledged or acted upon until the next active edge of a clock signal. (2)A system whose operation is synchronized by a clock signal.

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