1. A Si pn junction diode is described by its I-V equation, I?= Is exp (V?/V?) ,where V?=25mV, Is=10-14A . It is desired to derive constant drop and PWL models for the diode assuming an operating current between 1mA and 3mA.
a) Compute the constant drop model parameter, VDo.
b) Compute the piece wise linear (PWL) model parameters: VDo, rD.
c) Plot in the same graph the real diode I-V curve and the CD and PWL models.
2. The above described diode is included in a simple circuit in series with a DC power supply, VS=10V and a resistor, R=5k?
a) Use the numerical iterative procedure to compute the exact solution (ID, VD).
b) Use the CD model derived in problem 2 to find an approximate solution for (ID, VD).
c) Use the PWL model derived in problem 2 to find an approximate solution for (ID, VD).
d) Compare the three solutions and comment on the error.
3. Repeat problem 3 with VS=10V, and R=1k? (different diode operating region!)
a) Use the numerical iterative procedure to compute the exact solution (ID, VD).
b) Use the CD model derived in problem 2 to find an approximate solution for (ID, VD).
c) Use the PWL model derived in problem 2 to find an approximate solution for (ID, VD).
d) Compare the three solutions and comment on the error. Is it higher than in prob 3? Why?