Logic Families and Their Characteristics MCQs

Question 1

The most common TTL series ICs are:

Accepted Answer

7400

Answer

E-MOSFET

Answer

quad

Answer

AC00

Question 2

Which family of devices has the characteristic of preventing saturation during operation?

Accepted Answer

ECL

Answer

TTL

Answer

MOS

Answer

IIL

Question 3

How many 74LSTTL logic gates can be driven from a 74TTL gate?

Accepted Answer

20

Answer

10

Answer

200

Answer

400

Question 4

What is the difference between the 74HC00 series and the 74HCT00 series of CMOS logic?

Accepted Answer

The HCT series is input and output voltage compatible with TTL.

Answer

The HCT series is faster.

Answer

The HCT series is slower.

Answer

The HCT series is not input and output voltage compatible with TTL.

Question 5

Why are the maximum value of VOL and the minimum value of VOH used to determine the noise margin rather than the typical values for these parameters?

Accepted Answer

These are worst-case conditions.

Answer

These are normal conditions.

Answer

These are best-case conditions.

Answer

It doesn't matter what values are used.

Question 6

What is the standard TTL noise margin?

Accepted Answer

0.4 V

Answer

5.0 V

Answer

0.0 V

Answer

0.8 V

Question 7

Which logic family is characterized by a multiemitter transistor on the input?

Accepted Answer

TTL

Answer

ECL

Answer

CMOS

Answer

None of the above

Question 8

How is the speed–power product of a logic family determined?

Accepted Answer

The propagation delay in ns is multiplied by the power dissipation in mW.

Answer

The propagation delay in s is multiplied by the power dissipation in mW.

Answer

The propagation delay in ms is multiplied by the power dissipation in W.

Answer

The propagation delay in ns is multiplied by the power dissipation in W.

Question 9

The problem of the VOH(min) of a TTL IC being too low to drive a CMOS circuit and meet the CMOS requirement of VIH(min) is usually easily overcome by:

Accepted Answer

adding an external pull-up resistor to VCC

Answer

adding a fixed voltage-divider bias resistive network at the output of the TTL device

Answer

avoiding this condition and only using TTL to drive TTL

Answer

adding an external pull-down resistor to ground