Logic Families and Their Characteristics

MCQsQuestion.com has 31 Question/Answers about Topic Logic Families and Their Characteristics

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

How many 74LSTTL logic gates can be driven from a 74TTL gate?
  • A. 10
  • B. 20
  • C. 200
  • D. 400
  • Correct Answer: Option B

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

When is a level-shifter circuit needed in interfacing logic?
  • A. A level shifter is always needed.
  • B. A level shifter is never needed.
  • C. when the supply voltages are the same
  • D. when the supply voltages are different
  • Correct Answer: Option D

Why is a pull-up resistor needed when connecting TTL logic to CMOS logic?

Why is a pull-up resistor needed when connecting TTL logic to CMOS logic?
  • A. to increase the output LOW voltage
  • B. to decrease the output LOW voltage
  • C. to increase the output HIGH voltage
  • D. to decrease the output HIGH voltage
  • Correct Answer: Option C

The problem of interfacing IC logic families that have different supply voltages (VCC

The problem of interfacing IC logic families that have different supply voltages (VCC
  • A. level-shifter
  • B. tristate shifter
  • C. decoupling capacitor
  • D. pull-down resistor
  • Correct Answer: Option A

The word “interfacing” as applied to digital electronics usually means:

The word “interfacing” as applied to digital electronics usually means:
  • A. a conditioning circuit connected between a standard TTL NAND gate and a standard TTL OR gate
  • B. a circuit connected between the driver and load to condition a signal so that it is compatible with the load
  • C. any gate that is a TTL operational amplifier designed to condition signals between NMOS transistors
  • D. any TTL circuit that is an input buffer stage
  • Correct Answer: Option B

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

The problem of different current requirements when CMOS logic circuits are driving TTL logic circuits can usually be overcome by the addition of:
  • A. a CMOS inverting bilateral switch between the stages
  • B. a TTL tristate inverting buffer between the stages
  • C. a CMOS noninverting bilateral switch between the stages
  • D. a CMOS buffer or inverting buffer
  • Correct Answer: Option D

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:

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:
  • A. adding a fixed voltage-divider bias resistive network at the output of the TTL device
  • B. avoiding this condition and only using TTL to drive TTL
  • C. adding an external pull-down resistor to ground
  • D. adding an external pull-up resistor to VCC
  • Correct Answer: Option D

Why is the operating frequency for CMOS devices critical for determining power dissipation?

Why is the operating frequency for CMOS devices critical for determining power dissipation?
  • A. At low frequencies, power dissipation increases.
  • B. At high frequencies, the gate will only be able to deliver 70.7 % of rated power.
  • C. At high frequencies, charging and discharging the gate capacitance will draw a heavy current from the power supply and thus increase power dissipation.
  • D. At high frequencies, the gate will only be able to deliver 70.7 % of rated power and charging and discharging the gate capacitance will draw a heavy current from the power supply and thus increase power dissipation.
  • Correct Answer: Option C

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

How is the speed–power product of a logic family determined?
  • A. The propagation delay in s is multiplied by the power dissipation in mW.
  • B. The propagation delay in ms is multiplied by the power dissipation in W.
  • C. The propagation delay in ns is multiplied by the power dissipation in mW.
  • D. The propagation delay in ns is multiplied by the power dissipation in W.
  • Correct Answer: Option C

What is the major advantage of ECL logic?

What is the major advantage of ECL logic?
  • A. very high speed
  • B. wide range of operating voltage
  • C. very low cost
  • D. very high power
  • Correct Answer: Option A

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

Which logic family is characterized by a multiemitter transistor on the input?
  • A. ECL
  • B. CMOS
  • C. TTL
  • D. None of the above
  • Correct Answer: Option C

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

Which family of devices has the characteristic of preventing saturation during operation?
  • A. TTL
  • B. MOS
  • C. ECL
  • D. IIL
  • Correct Answer: Option C

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

What is the difference between the 74HC00 series and the 74HCT00 series of CMOS logic?
  • A. The HCT series is faster.
  • B. The HCT series is slower.
  • C. The HCT series is input and output voltage compatible with TTL.
  • D. The HCT series is not input and output voltage compatible with TTL.
  • Correct Answer: Option C

How does the 4000 series of CMOS logic compare in terms of speed and power dissipation to the standard family of TTL logic?

How does the 4000 series of CMOS logic compare in terms of speed and power dissipation to the standard family of TTL logic?
  • A. more power dissipation and slower speed
  • B. more power dissipation and faster speed
  • C. less power dissipation and faster speed
  • D. less power dissipation and slower speed
  • Correct Answer: Option D

Special handling precautions should be taken when working with MOS devices. Which of the following statements is not one of these precautions?

Special handling precautions should be taken when working with MOS devices. Which of the following statements is not one of these precautions?
  • A. All test equipment should be grounded.
  • B. MOS devices should have their leads shorted together for shipment and storage.
  • C. Never remove or insert MOS devices with the power on.
  • D. Workers handling MOS devices should not have grounding straps attached to their wrists.
  • Correct Answer: Option D
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