ECE 595 Assignment 3

Extend your matlab circuit analysis program to handle diodes. The diode characteristic equation is given by

where IS = 1e-14 and VT = 0.025 V.

Your program should plot the current through the diode and the norm of the solution step size as a function of iteration.

Solve the following problems:

  1. solve for diode voltage given diode current:
    D D1 1 0  0
    I I1 0 1 .01
    

  2. solve for diode voltage with series resistance, given current source:
    D D1 1 0  0
    R R1 2 1 100
    I I1 0 2 .01
    

  3. Solve for diode voltage and current given voltage source:
    D D1 1 0  0
    R R1 2 1 100
    V V1 2 0  3
    

  4. Solve for diode voltages and current (two diodes) forward biased:
    D D1 1 0  0
    D D2 2 1  0
    R R1 3 2 100
    V V1 3 0  3
    

  5. Solve for diode voltages (two diodes) reverse biased:
    D D1 1 0  0
    D D2 2 1  0
    V V1 2 0 -3
    
    Explain why the analysis is nearly singular.


Maintained by John Loomis, last updated 30 Aug 2002