Basics of electronic ...

Exercise 1:

Plot the characteristics of the 1N4148 silicon diode and the 1N34A germanium diode. To do this, create diode models in LTSpice by typing the following as Spice directives:

a) For a silicon diode:

.model 1N4148 D(Is=1n N=2 Rs=1 Ikf=150m Xti=3 Eg=1.11 Cjo=4p M=.3333 Vj=.8 Fc=.5 Bv=100 Ibv=100u Tt=10n)

b) For a germanium diode:

.model 1N34A D(bv=75 cjo=0.5e-12 eg=0.67 ibv=18e-3 is=2e-7 rs=7 n=1.3 vj=0.1 m=0.27)

Then create the following diagram:

and perform DC Sweep simulations with voltages from 0V to 21V in 0.1 steps. Compare the results obtained for the two types of diodes. When you're done, compare the results with the video below.

Exercise 2:

Using the simulation from the previous exercise, extend the voltage range from -120V to 21V in steps of 0.01. Observe the phenomenon of diode breakdown in the reverse bias of the diode. Determine the breakdown voltage for both diodes. When you're done, compare the results with the video below.