Electrical Engineering Answers

A 61300 V concentric cable with two inter-sheaths has a core diameter of 2.3 cm;

dielectric material of 3.3 mm thickness constitutes three zones of insulation.

Determine the maximum stress in each of the three layers, if 21300 V is maintained

across each of the inner two layers.

Draw an Energy Material Signal Flow for a simple Submarine

(1) The minimum subthreshold swing of a MOSFET at T = 350 K is ( ). 

A. 30 mV/decade B. 60 mV/decade C. 70 mV/decade D. 90 mV/decade 

(2) Which of the following causes the drain current to increase with VDS in the 

saturation region? ( ). 

A. channel length modulation B. inversion charge in the channel 

C. the body effect D. mobility degradation 

(3) A MOSFET is biased in the saturation region with a transconductance of gm = 10 

mS in the absence of channel length modulation effects. What would the gm be if 

the CLM parameter was λ = 0.02 V-1 for ΔVDS = 3V? ( ). 

A. 9.94 mS B. 10 mS C. 10.6 mS D. 0.6 mS 

(4) At room temperature, a possible value for the mobility of electrons in the inversion 

layer of a silicon n-channel MOSFET is ( ). 

A. 450 cm2/Vꞏs B. 1350 cm2/Vꞏs C. 1800 cm2/Vꞏs D. 3600 cm2/Vꞏs 

Consider a short n-channel MOSFET with Toxe = 2 nm and WT = 35 nm. Suppose 

the threshold voltage (VT) for this device is simply defined to be the value of VGS at 

which the normalized drain current IDS/(W/L) reaches 100 nA for VDS = 100 mV. 

(1) Determine the subthreshold swing, S. 

(2) If the normalized leakage current must be less than or equal to 10 pA when VGS

= 0 V and VDS = 100 mV, what is the minimum threshold voltage this device can 

have? 

(3) Why is a small value of S desirable?

What is the aspect ratio of channel width to length of n-MOS transistor for the 

following parameters: gm = 1.2 mA/V, VT = 0.5 V, VGS = 2 V, VDS = 1 V, kn = 120 

μA/V2.