Digital Electronics Semester 1

Dual In-Line Package (DIP)

-A very common IC package with two parallel rows of pins intended to be inserted into a socket of through holes drilled in a printed circuit board. -One style of integrated circuit package which has two rows of lead.

DeMorgan's Theorems

1) Theorem stating that the complement of a sum (OR operation) equals the product (AND operation) of the complements, and 2) Theorem stating that the complement of a product (AND operation) equals the sum (OR operation) of the complements.

Breadboard

A circuit board for wiring temporary circuits, usually used for prototypes or laboratory work.

Logic Diagram

A diagram, similar to a schematic, showing the connection of logic gates.

Transistor-Transistor (TTL)

A family of digital logic devices whose basic element is the bipolar junction transistor.

Engineering Notation

A floating point system in which numbers are expressed as products consisting of a number greater than one multiplied by an appropriate power of ten that is some multiple of three.

Karnaugh Map

A graphical tool for finding the maximum SOP or POS simplification of a Boolean expression. A _____ works by arranging the terms of an expression so that variable scans are cancelled by grouping minterms or maxterms.

Truth Table

A list of all possible input values to a digital circuit, listed in ascending binary order, and the output response for each input combination.

Current

A movement of electrical charges around a closed path or circuit.

Digital Multi-Meter(DMM)

A piece of test equipment used to measure voltage, current, and resistance in an electronic circuit.

Oscilloscope

A piece of test equipment used to view and measure a variety of different waveforms.

Datasheet

A printed specification giving details of the pin configuration, electrical properties, and mechanical profile of an electronic device.

Minterm

A product term in a Boolean expression where all possible variables appear once in true or complement form.

Fuse

A protective device in the current path that melts or breaks when current exceeds a predetermined maximum value.

Flip-Flop

A sequential circuit based on a latch whose output changes when its CLOCK input receives a pulse.

Cycle

A series of events that are regularly repeated in the same order.

Digital Waveform

A series of logic 1s and 0s plotted as a function of time.

Plastic Leaded Chip Carrier (PLCC)

A square IC package with leads on all four sides designed for surface mounting on a circuit board.

Maxterm

A sum term in a Boolean expression where all possible variables appear once in true or complement form.

Schematic Entry

A technique of entering CPLD design information by using a CAD (computer aided design) tool to draw a logic circuit as a schematic. The schematic can then be interpreted by design software to generate programming information for the CPLD.

Product Term

A term in a Boolean expression where one or more true or complement variables are AND'ed.

Sum Term

A term in a Boolean expression where one or more true or complement variables are OR'ed.

Sum-of-Products (SOP)

A type of Boolean expression where several product terms are summed (OR'ed) together.

Product-of-Sums (POS)

A type of Boolean expression where several sum terms are multiplied (AND'ed) together.

Digital

A way of representing a physical quantity by a series of binary numbers. A ____ representation can have only specific discrete values.

Analog

A way of representing some physical quantity, such as temperature or velocity, by a proportional continuous voltage or current. An ___ voltage or current can have any value within a defined range.

SI Notation

Abbreviation of System International, a system of practical units based on the meter, kilogram, second, ampere, Kelvin, mole, and candela.

Inverter

Also called a NOT gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.

NOT Gate

Also called an INVERTER gate or an inverting buffer. A logic gate that changes its input logic level to the opposite state.

Small Outline IC (SOIC)

An IC package similar to a DIP, but smaller, which is designed for automatic placement and soldering on the surface of a circuit board.

Large Scale Integration (LSI)

An IC that contains circuitry equivalent to 100 gates or more.

Medium Scale Integration (MSI)

An IC that contains circuitry equivalent to more than 11 and less than 100 gates.

Boolean Expression

An algebraic expression made up of Boolean variables and operators, such as AND (-), OR (+), or NOT (-). Also referred to as Boolean function or a logic function.

Square Wave

An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value.

Seven-Segment Display

An array of seven independently controlled light-emitting diodes (LED) or liquid crystal display (LCD) elements, shaped like a figure-8, which can be used to display decimal digits and other characters by turning on the appropriate elements.

Capacitor

An electrical device used to store electrical charge.

Integrated Circuit (IC)

An electronic circuit having many components, such as transistors, diodes, resistors, and capacitors, in a single package.

Logic Gate

An electronic circuit that performs a Boolean algebraic function.

LED

An electronic device that conducts current in one direction only and illuminates when it is conducting. Light-emitting diode.

Small-Scale Integration (SSI)

An integrated circuit having 12 or fewer gates in one package.

Logic Circuit

Any circuit that behaves according to a set of logic rules.

Resistor Color Code

Coding system of colored stripes on a ___ to indicate the ___'s value and tolerance.

Propagation Delays (tPLH/tPHL)

Delay from the time a signal is applied to the time when the output makes its change.

OR Gate

Digital circuit that implements the ___ operation. The output of this circuit is HIGH (logic level 1) if any or all of its inputs are HIGH.

AND Gate

Digital circuit that implements the ____ operation. The output of this circuit is HIGH only if all of its inputs are HIGH.

Combinational Logic

Digital circuitry in which an output is derived from the combination of inputs, independent of the order in which they are applied.

Sequential Logic

Digital circuitry in which the output state of the circuit depends not only on the states of the inputs, but also on the sequence in which they reached their present states.

Clock

Digital signal in the form of a rectangular pulse train or a square wave.

Duty Cycle (DC)

Fraction of the total period that a digital waveform is in the HIGH state. __ = th/T (often expressed as a percentage: %__ = th/Tx100%).

Ohm's Law

In electric circuits, I=V/R.

Printed Circuit Board

Insulating board containing conductive tracks for circuit connections.

NAND Gate

Logic circuit that operates like an AND gate followed by an INVERTER. The output of a ___ gate is LOW (logic level 0) only if all inputs are HIGH (logic level 1).

NOR Gate

Logic circuit that operates like an OR gate followed by an INVERTER. The output of a ___ gate is LOW (logic level 0) when any or all inputs are HIGH (logic level 1).

Solder

Metallic alloy of tin and lead that is used to join two metal surfaces.

Scientific Notation

Numbers entered as a number from one to ten multiplied by a power of ten.

Sine Wave

One in which amplitude varies in proportion to the sine function of an angle.

Series Circuit

One that has only one path current.

Parallel Circuit

One that has two or more branches for separate current from one voltage source.

Resistance

Opposition to current. Unit is the ohm.

Soldering

Process of joining two metallic surfaces to make an electrical contact by melting solder (usually tin and lead) across them.

Don't Care Condition

Situation when a circuit's output level for a given set of input conditions can be assigned as either a 1 or 0.

Schottky TTL

TTL subfamily that uses the basic TTL standard circuit except that it uses a Schottky barrier code (SBD) connected between the base and the collector of each transistor for faster switching.

555 Timer

TTL-compatible IC that can be wired to operate in several different modes, such as a one-shot and an astable multivibrator.

Transistor

Term derived from "transfer resistor." Semiconductor device that can be used as an amplifier or as an electronic switch.

Simulation

Testing design function by specifying a set of inputs and observing the resultant outputs. ___ is generally shown as a series of input and output waveforms.

Kirchhoff's Current Law (KCL)

The algebraic sum of all currents into and out of any branch point in a circuit must equal zero.

Kirchhoff's Voltage Law (KVL)

The algebraic sum of all voltages around any closed path must equal zero.

Period

The amount of time required for one complete cycle of a periodic event or waveform.

Conventional Current

The direction of current flow associated with positive charge in motion. The current flow direction is from a positive to negative potential, which is in the opposite direction of electron flow.

Logic HIGH

The higher of two voltages in a digital system with two logic levels.

Amplitude

The instantaneous voltage of a waveform. Often used to mean maximum ___, or peak voltage, or a pulse.

Most Significant Bit (MSB)

The leftmost bit in a binary number. This bit has the number's largest positional multiplier.

Logic LOW

The lower of two voltages in a digital system with two logic levels.

Frequency

The number of cycles per unit time of a periodic waveform.

Falling Edge

The part of a pulse where the logic level is in transition from a HIGH to a LOW.

Tinning

The process of applying a thin coat of solder to materials prior to their being soldered; for example, application of a light coat of solder to the filaments of a conductor to hold the filaments in place prior to soldering the conductor.

Distributive Property

The property that allows us to distribute ("multiply through") an AND across several OR functions. For example, a(b+c)=ab+ac.

Least Significant Bit (LSB)

The rightmost bit of a binary number. This bit has the number's smallest positional multiplier.

Cell

The smallest unit of Karnaugh map, corresponding to one line of a truth table. The input variables are the ___'s coordinates and the output variable is the ___'s contents.

Solder Bridge

The unwanted formation of a conductive path of solder between conductors.

Toggle

To switch from one effect, feature, or state to another.

Soldering Iron

Tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten.

Adjacent Cell

Two cells in a K-map are adjacent if there is only one variable that is different between the coordinates of the two cells.

Clocked D Flip-Flop

Type of flip-flop in which the D (data) input is the synchronous input.

Hertz (Hz)

Unit of frequency. One ___ equals one cycle per second.

Ohm

Unit of resistance. Value of one ___ allow current of one ampere with potential difference of one volt.