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