1. The Maximum and minimum output of the Differential amplifiers is defined as:
a) Vmax = VDD, Vmin = -VDD
b) Vmax = VDD, Vmin = Rd.Iss
c) Vmax = VDD, Vmin = VDD – Rd.Iss
d) None of the mentioned
Explanation: Vmax = VDD, Vmin = VDD – Rd.Iss
2. In Common Mode Differential Amplifier, the outputs Vout1 and Vout2 are related as:
a) Vout2 is in out of phase with Vout1 with same amplitude
b) Vout2 and Vout1 have same amplitude but the phase difference is 90 degrees
c) Vout1 and Vout2 have same amplitude and are in phase with each other and their respective inputs
d) Vout1 and Vout2 have same amplitude and are in phase with each other but out of phase with their respective inputs
Explanation: Vout1 and Vout2 have same amplitude and are in phase with each other but out of phase with their respective inputs
3. In a small signal differential gain vs input CM level graph, the gain decreases after V2 due to:
a) As the input voltage increases, the output will be clipped
b) When the input voltage to the transistors are high, the transistor enters saturation region and increases the current, which inturn decreases the output voltage = VDD – Rd.Iss
c) When Common Mode voltage is greater than or equal to V2, the input transistors enter triode region, the gain begins to fall
d) Increasing the input voltage beyond V2 causes the gate oxide to conduct and the gain is reduced
Explanation: When Common Mode voltage is greater than or equal to V2, the input transistors enter triode region, the gain begins to fall
4. Microelectronic technology cannot be characterized by
a) minimum feature size
b) power dissipation
c) production cost
d) designing cost
Explanation: Microelectronic technology cannot be characterized by designing cost
5. Which model is used for scaling?
a) constant electric scaling
b) constant voltage scaling
c) costant electric and voltage scaling
d) costant current model
Explanation: Constant electric scaling model and constant voltage scaling model is used for scaling.
6. α is used for scaling
a) linear dimensions
b) vdd
c) oxide thickness
d) non linear
Explanation: α is used as the scaling factor for linear dimensions where as β is used for supply voltage Vdd, gate oxide thickness etc.
7. For constant voltage model,
a) α = β
b) α = 1
c) α = 1/β
d) β = 1
Explanation: For constant voltage model, β = 1 and 1/β is chosen for the scaling for all voltages.
8. For constant electric field model,
a) β = α
b) α = 1
c) α = 1/β
d) β = 1
Explanation: For constant voltage model, β = α.
9. Gate area can be given as
a) L/W
b) L * W
c) 2L/W
d) L/2W
Explanation: Gate area Ag can be given as the product of length and the width of the channel.
10.Gate area is scaled by
a) α
b) 1/α
c) 1/α2
d) α2
Explanation: Gate area is given as the product of length and width of the channel and it can be scaled by 1/α2.