VLSI Design and Technology MCQ with Answers [21-40].
21. In two-stage op-amp, what is the purpose of compensation circuitry?
The purpose of compensation circuitry is to achieve stable closed-loop performance.
22. impurities are added to the wafer of the crystal.
Explanation: p impurities are introduced as the crystal is grown. This increases the hole concentration in the device.
23. In nMOS device, gate material could be.......
Explanation: In nMOS device, the gate material could be metal or polysilicon. This polysilicon layer has heavily doped polysilicon deposited by CVD.
24. In CMOS circuits, which type of power dissipation occurs due to switching of transient current and charging & discharging of load capacitance?
No Explanation.
25. In accordance to the scaling technology, the total delay of the logic circuit depends on
All of the above
26. The photoresist layer is exposed to .......
Explanation: The photoresist layer is exposed to ultraviolet light to mark the regions where diffusion is to take place.
27. In a chip, which type/s of pad design/s is/are adopted to solve the problem of pin count?
Three state pad design
28. Which level of routing resources are supposed to be the dedicated lines allowing output of each tile to connect directly to every input of eight surrounding tiles?
Ultra fast local resources
29. The power consumption of static CMOS gates varies with the ....... of power supply voltage.
Square
30. What kind of substrate is provided above the barrier to dopants?
Explanation: Above a layer of silicon dioxide which acts as a barrier, an insulating layer is provided upon which other layers may be deposited and patterned.
31. Which factor/s play/s a crucial role in determining the speed of CMOS logic gate?
All of the above
32. In high noise margin (NMH), the difference in magnitude between the maximum HIGH output voltage of driving gate and the maximum HIGH voltage is recognized by the ....... gate.
Receiving
33. Maze routing is used to determine the ........ path for a single wire between a set of points, if any path exists.
Maze routing is used to determine the shortest path for a single wire between a set of points, if any path exists.
34. Heavily doped polysilicon is deposited using ........
Explanation: The polysilicon layer consists of heavily doped polysilicon deposited by chemical vapour deposition.
35. Contact cuts are made in .......
Explanation: Contact cuts are made in the desired polysilicon area, source and gate. COntact cuts are those places where connection has to be made.
36. In diffusion process ...... impurity is desired.
Explanation: Diffusion is carried out by heating the wafer to high temperature and passing a gas containing the desired ntype impurity.
37. In spartan-3 family architecture, which programmable functional element accepts two 18 bit binary numbers as inputs and computes the product?
Multiplier Blocks
38. Which type of CPLD packaging comprises pins on all four sides that wrap around the edges of chip?
Plastic - Leaded cheap carrier
39. Which is used for the interconnection?
Explanation: Aluminium is the suitable material used for the circuit interconnection or connecting two layers.
40. An antifuse element initial provides ....... between two conductors in absence of the application of sufficient programming voltage.
Insulation