VLSI A2

1.     nMOS devices are formed in

• p-type substrate of high doping level

• n-type substrate of low doping level

• p-type substrate of moderate doping levell

• n-type substrate of high doping level

2.       what is the condition for non-saturated region

• Vds = Vgs – Vt

• Vgs lesser than Vt

• Vds lesser than Vgs – Vt

•  Vds greater than Vgs – Vt

3.       Inversion layer in enhancement mode consists of excess of

•  positive carriers

• Negative Carriers

• both in equal quantity

• neutral carriers

4.     What is the condition for linear region?

• Vgs lesser than Vt

• Vgs greater than Vt

• Vds lesser than Vgs

• Vds greater than Vgs

5.       As source drain voltage increases, channel length  

• Increases

• Decreases

• logarithmically increases

• exponentially increases

6.      CMOS inverter has ______ regions of operation

• Three

• Four

• Two

• five

7.       Mobility depends on

• Electric field

• Vg

• Vdd

• Channel length

What is the input resistance of CMOS inverter?

• High

• low

• very low

• none of the mentioned

  Fast gate can be built by keeping

• Low output capacitance

• high on resistance

• high output capacitance

•         input capacitance does not affect speed of the gate

    Source and drain in nMOS device are isolated by

• 1

• 2

• 3

• 4