Q.1

A current-sourcing transistor may also be referred to as a pull-down transistor.

  • True
  • False
Q.2

The data sheet for the 74 series of TTL ICs shows that Vcc has a range of 4.5 V to 5.5 V.

  • True
  • False
Q.3

Propagation delay is important because ________.

  • the logic gates must be given a short break during each clock cycle or else they will overheat
  • it limits the maximum operating frequency of a gate
  • it is a measure of how long the clock must be applied to the gate before it will make the required decision
  • all the gates in a system must have the same propagation times in order to be compatible
Q.4

The IEEE/ANSI notation of an internal underlined diamond denotes:

  • totem-pole outputs.
  • open-collector outputs.
  • quadrature amplifiers.
  • tristate buffers.
Q.5

What are the major differences between the 5400 and 7400 series of ICs?

  • The 5400 series are military grade and require tighter supply voltages and temperatures.
  • The 5400 series are military grade and allow for a wider range of supply voltages and temperatures.
  • The 7400 series are an improvement over the original 5400s.
  • The 7400 series was originally developed by Texas Instruments. The 5400 series was brought out by National Semiconductors after TI's patents expired, as a second supply source.
Q.6

What is the increase in switching speed between 74LS series TTL and 74HC/HCT (High-Speed CMOS)?

  • 5
  • 10
  • 50
  • 100
Q.7

Logic circuits that are designated as buffers, drivers, or buffer/drivers are designed to have:

  • a greater current/voltage capability than an ordinary logic circuit.
  • greater input current/voltage capability than an ordinary logic circuit.
  • a smaller output current/voltage capability than an ordinary logic.
  • greater input and output current/voltage capability than an ordinary logic circuit.
Q.8

Most TTL gates use the totem-pole output arrangement.

  • True
  • False
Q.9

What is the increase in switching speed between 74LS series TTL and 74HC/HCT (High-Speed CMOS)?

  • 5
  • 10
  • 50
  • 100
Q.10

The major advantage of CMOS logic circuits over TTL is very low power consumption.

  • True
  • False
Q.11

________ output levels would not be a valid LOW for a TTL gate.

  • 0.2 V
  • 0.3 V
  • 0.5 V
  • All of the above.
Q.12

The bipolar TTL logic family that was developed to increase switching speed by preventing transistor saturation is:

  • emitter-coupled logic (ECL).
  • current-mode logic (CML).
  • transistor-transistor logic (TTL).
  • emitter-coupled logic (ECL) and transistor-transistor logic (TTL).
Q.13

Which of the following statements apply to CMOS devices?

  • The devices should not be inserted into circuits with the power on.
  • All tools, test equipment, and metal workbenches should be tied to earth ground.
  • The devices should be stored and shipped in antistatic tubes or conductive foam.
  • All of the above.
Q.14

A logic signal experiences a delay in going through a circuit. The two propagation delay times are defined as:

  • tPLH and tPHL.
  • tDLH and tDHL.
  • tHPL and tlph.
  • tLDH and tHDL.
Q.15

Which of the following will not normally be found on a data sheet?

  • Minimum HIGH level output voltage
  • Maximum LOW level output voltage
  • Minimum LOW level output voltage
  • Maximum HIGH level input current
Q.16

The fan-out of CMOS gates is frequency dependent.

  • True
  • False
Q.17

Which of the following logic families has the highest noise margin?

  • TTL
  • LS TTL
  • CMOS
  • HCMOS
Q.18

The dc noise margins calculated using the proper values from a standard TTL data sheet are the worst-case margins. The typical dc noise margins are usually somewhat higher.

  • True
  • False
Q.19

The minimum input voltage recognized as HIGH by a TTL gate is ________.

  • 2.0 V
  • 2.4 V
  • 0.8 V
  • 5.0 V
Q.20

What does ECL stand for?

  • It stands for electron-coupled logic; all of the devices used within the gates are N-type transistors.
  • It stands for emitter-coupled logic; all of the inputs are coupled into the device through the emitters of the input transistors.
  • It stands for emitter-coupled logic; all of the emitters of the input transistors are connected together and each transistor functions as an emitter follower.
  • It stands for energy-coupled logic; the input energy is amplified by the input transistors and allows the device to deliver higher output currents.
0 h : 0 m : 1 s