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- Question
When is a level-shifter circuit needed in interfacing logic?
Options- 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
- when the supply voltages are different
- 1. Using the schematic diagram of a TTL NAND gate, determine the state of each transistor (ON or OFF) when all inputs are high.
Options- A. Q1-ON, Q2-OFF, Q3-ON, Q4-OFF
- B. Q1-ON, Q2-ON, Q3-OFF, Q4-OFF
- C. Q1-OFF, Q2-OFF, Q3-ON, Q4-ON
- D. Q1-OFF, Q2-ON, Q3-OFF, Q4-ON Discuss
- 2. The term buffer/driver signifies the ability to provide low output currents to drive light loads.
Options- A. True
- B. False Discuss
- 3. 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?
Options- A. These are worst-case conditions.
- B. These are normal conditions.
- C. These are best-case conditions.
- D. It doesn't matter what values are used. Discuss
- 4. The time needed for an output to change from the result of an input change is known as:
Options- A. noise immunity
- B. fan-out
- C. propagation delay
- D. rise time Discuss
- 5. What should be done to unused inputs on TTL gates?
Options- A. They should be left disconnected so as not to produce a load on any of the other circuits and to minimize power loading on the voltage source.
- B. All unused gates should be connected together and tied to V
- C. All unused inputs should be connected to an unused output; this will ensure compatible loading on both the unused inputs and unused outputs.
- D. Unused AND and NAND inputs should be tied to VCC through a 1 kΩ resistor; unused OR and NOR inputs should be grounded. Discuss
- 6. What is the advantage of using low-power Schottky (LS) over standard TTL logic?
Options- A. more power dissipation
- B. less power dissipation
- C. cost is less
- D. cost is more Discuss
- 7. How can ECL have both a NOR and an OR output?
Options- A. ECL does not have this feature.
- B. They are simply the inverse of each other. Discuss
- 8. How does the 4000 series of CMOS logic compare in terms of speed and power dissipation to the standard family of TTL logic?
Options- 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 Discuss
- 9. The high input impedance of MOSFETs:
Options- A. allows faster switching
- B. reduces input current and power dissipation
- C. prevents dense packing
- D. creates low-noise reactions Discuss
- 10. What is the difference between the 54XX and 74XX series of TTL logic gates?
Options- A. 54XX is faster.
- B. 54XX is slower.
- C. 54XX has a wider power supply and expanded temperature range.
- D. 54XX has a narrower power supply and contracted temperature range. Discuss
Logic Families and Their Characteristics problems
Search Results
Correct Answer: Q1-OFF, Q2-ON, Q3-OFF, Q4-ON
Correct Answer: False
Correct Answer: These are worst-case conditions.
Correct Answer: propagation delay
Correct Answer: Unused AND and NAND inputs should be tied to VCC through a 1 kΩ resistor; unused OR and NOR inputs should be grounded.
Correct Answer: less power dissipation
Correct Answer: They are simply the inverse of each other.
Correct Answer: less power dissipation and slower speed
Correct Answer: reduces input current and power dissipation
Correct Answer: 54XX has a wider power supply and expanded temperature range.
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