Logic Families and Their Characteristics MCQs

Question 1

The problem of different current requirements when CMOS logic circuits are driving TTL logic circuits can usually be overcome by the addition of:

Accepted Answer

a CMOS buffer or inverting buffer

Answer

a CMOS inverting bilateral switch between the stages

Answer

a TTL tristate inverting buffer between the stages

Answer

a CMOS noninverting bilateral switch between the stages

Question 2

Totem-pole outputs ________ be connected ________ because ________.

Accepted Answer

cannot, together, if the outputs are in opposite states excessively high currents can damage one or both devices

Answer

can, in parallel, sometimes higher current is required

Answer

should, in series, certain applications may require higher output voltage

Answer

can, together, together they can handle larger load currents and higher output voltages

Question 3

The high input impedance of MOSFETs:

Accepted Answer

reduces input current and power dissipation

Answer

allows faster switching

Answer

prevents dense packing

Answer

creates low-noise reactions

Question 4

The output current capability of a single 7400 NAND gate when HIGH is called ________.

Accepted Answer

source current

Answer

sink current

Answer

IOH

Answer

source current of IOH

Question 5

The time needed for an output to change from the result of an input change is known as:

Accepted Answer

propagation delay

Answer

noise immunity

Answer

fan-out

Answer

rise time

Question 6

The problem of interfacing IC logic families that have different supply voltages (VCC's) can be solved by using a:

Accepted Answer

level-shifter

Answer

tristate shifter

Answer

decoupling capacitor

Answer

pull-down resistor

Question 7

What is the advantage of using low-power Schottky (LS) over standard TTL logic?

Accepted Answer

less power dissipation

Answer

more power dissipation

Answer

cost is less

Answer

cost is more

Question 8

When is a level-shifter circuit needed in interfacing logic?

Accepted Answer

when the supply voltages are different

Answer

A level shifter is always needed.

Answer

A level shifter is never needed.

Answer

when the supply voltages are the same

Question 9

A TTL totem-pole circuit is designed so that the output transistors:

Accepted Answer

are never on together

Answer

are always on together

Answer

provide linear phase splitting

Answer

provide voltage regulation