Question 1:
By plotting the NMOS/PMOS data measured for ID vs VGS, find and report values of VTH and K (W/L). How do the VTH and K (W/L) values for the NMOS and PMOS compare?
Answer 1:
NMOS:
Consider Scopy plot obtained the in the lab activity:
The threshold voltage can be obtained by observing the data on the plot, where the transistor starts conducting (turns on). In our case the measured threshold voltage is around VTH=1.8V.
The VGS value is obtained by taking the largest voltage value on the x-axis. In this case, VGS=2.4V
In the saturation region, the current flowing through the transistor can be measured by dividing the maximum voltage obtained on the Y axis by the resistor value used in the setup (100Ω).
IDSAT = 4.8V/100Ω = 48mA
K(W/L) is obtained using the formula for drain current in the saturation region.
IDSAT = K(W/L) * (VGS-VTH)2
K(W/L) = 0.13
PMOS:
Follow the same steps as for the NMOS, but using the appropriate Scopy plot
We obtain: VTH=2.9V, VGS=4.1V, IDSAT=3.8V/100Ω=38mA
K(W/L) = 0.026