Logic Gates

How many two-input NAND gates are required to produce a two-input exclusive OR gate?

4

The truth table for three variables has how many possible combinations?

8

Which of the following could be a Boolean expression for a three-input or gate?

A+B+C=Y

Which of the following is sometimes referred to as the "all or nothing" gate?

AND

If a National Semiconductor digital DIP IC had the number 74HC08N printed on the top, what type of component would it be?

CMOS

Which family of digital ICs uses parts comparable to IGFETs?

CMOS

It is uncommon for logic functions to be programmed using software

FALSE

Which type gate is generally more widely available than any other gate?

NAND

The truth table for four variables has 16 possible combinations.

True

This is the logic symbol for what type of gate?

XOR

Which logic gate provides a low output only when an odd number of inputs are high?

exclusive NOR

A logic _____ is a circuit that can decide to say yes or no at the output based upon inputs.

gate

The NOT circuit is another name for a(n) _____.

inverter

The unique characteristic of the XOR gate is that it produces a high output only when an odd number of high inputs are present

TRUE

The unique output of the AND function is a high output only when all inputs are high

TRUE

NAND gates are not as widely use as are other logic gates

FALSE

The AND gate is sometimes called the "any or all" gate

FALSE

The Boolean expression is a universal language used by engineers and technician in analog electronics

FALSE

The basic building block of any digital circuit is a flip-flop

FALSE

The bubble at the input of in inverter indicates that the active state is high

FALSE

The exclusive NOR gate is sometimes referred to as the "off but not even" gate

FALSE

The unique output of the NAND function is a low output only when all inputs are low.

FALSE

The basic operation of which of the following is sometimes compared to a mechanical single-pole 8-position rotary switch?

1-of-8 data selector

A data converter is often a one-package solution to a complicated logic problem.

False

A typical programmable array of logic gates may have 16 inputs and 8 outputs.

False

AND gates are often used to wire combinational logic circuits because they are easy to use and readily available.

False

The fuse map is a graphic method of describing the programming of a programmable logic device.

False

The product-of-sums form of Boolean expressions is called the minterm form by engineers, technicians, and scientists.

False

The truth table is a precise method of describing how an analog circuit works.

False

When using PBASIC, remark statements are used to clarify the program and are not executed by the microcontroller.

False

A pull-down resistor is often attached to the input of a gate in order to pull the input to the gate low when input switch is open

TRUE

Floating inputs on CMOS ICs can harm the IC

TRUE

Invert bubbles at the input of the AND gate convert it into a NOR function.

TRUE

Manufacturers' data manuals include traditional logic symbols and are recently including the newer IEEE functional logic symbols.

TRUE

Positive logic is most often used in digital electronics

TRUE

The CMOS family is a very low power and widely used family of digital ICs

TRUE

The NOR gate is not the same as the OR gate in operation

TRUE

The NOT circuit has one input and one output

TRUE

The terms negated, complemented, and inverted mean the same thing

TRUE

Which logic circuit law allows for the back and forth conversion from minterm to maxterm forms of Boolean expressions?

De Morgan

In lab programming of PAL and GAL ICs can be achieved using development software, a PC with an output cable, and a(n)

IC burner

This is an alternative logic symbol for what type of gate?

NOR

This is the logic symbol for a(n)

NOT gate (inverter)

Which of the following is a high-level language often used to solve combinational logic problems?

PBASIC

For more complex problems when there are more variables or when the logic circuit has several outputs, designers use a

Programmable array of logic gates

Very complex logic problems involving many inputs and outputs would be best solved using

Programmable-array logic

ICs that are much smaller and have shorter pins bent to be soldered to the traces on the top of a PC board are commonly called _____ packages.

SMT

A useful computer simulation instrument called a logic converter will invert back and forth between truth table, Boolean expressions and combinational logic diagrams.

True

Boolean expressions can be simplified by using Veitch diagrams, Venn diagrams, or the tabular method of simplification.

True

Combinational logic is an interconnection of logic gates to generate a specified logic function where the inputs result in an immediate output.

True

De Morgan's theorems allow the back and forth conversion from minterm to maxterm forms of Boolean expressions.

True

Digital circuits that have a memory or storage capability are called sequential logic circuits.

True

Karnaugh mapping is an easy-to-use graphic method of simplifying Boolean expressions.

True

The three methods used to describe a combinational logic circuit are by its truth table, Boolean expression, or logic symbol diagram.

True

When using 4000 series CMOS, what is the pin labeled that is connected to the positive of the power supply?

VDD

A useful computer simulation instrument that will convert back and forth between truth table, Boolean expressions, and combinational logic diagrams is called

a logic converter

With a keyboard version of a Boolean expression, the apostrophe outside the parenthesis means

a long overbar

In practical electronic equipment most digital ICs are mounted on

a printed circuit board

An IC that can be programmed by the user to execute a complex logic function is called

a programmable logic device

Boolean algebra is the algebra of _____.

logic

The unique output from the NOR gate is _____ only when all inputs are _____.

low, high

The letters LS in the core part number of a 7400 series IC stand for

low-power Schottky

The Boolean expression A ∙ B + C ∙ D = Y is called the sum-of-products or what form?

minterm

Manufacturers' data manuals generally refer to data selectors as ________.

multiplexors

Minterm Boolean expressions are used to create which logic circuits?

and-or

The noninverting _____ serves no logical purpose, but is used to supply greater drive current at its output.

buffer

The little invert bubble on the right end of a logic symbol means to invert the _____.

output

On a logic probe, the _____ lead is connected to the positive (+) of the power supply.

red

The data _______________ transfers data from a given data input to the output.

selector

Digital circuits that have a memory or storage capability are called

sequential

If caution is not exercised, CMOS ICs can be damaged by

static charges

Which of the following is a form of Boolean expressions?

sum-of-products

The _____ for a gate gives all the possible input combinations and the resulting outputs.

truth table

The first step in troubleshooting should be to

use your senses