a. An ideal diode blocks the flow of current in the direction opposite that of the diode’s arrow symbol. It can be used to make a half-wave rectifier as shown in Figure P27a. For the ideal diode, the voltage υ_L across the load R_L is given by

 

Suppose the supply voltage is

υs(t) = 3e^-t/3 sin(πt) V

where time t is in seconds. Write a MATLAB program to plot the voltage υ_L versus t for 0 ≤ t ≤ 10..

b. A more accurate model of the diode’s behavior is given by the offset diode model, which accounts for the offset voltage inherent in semiconductor diodes. The offset model contains an ideal diode and a battery whose voltage equals the offset voltage (which is approximately 0.6 V for silicon diodes) [Rizzoni, 2007]. The half-wave rectifier using this model is shown in Figure P27b. For this circuit,

Using the same supply voltage given in part a, plot the voltage υ_L versus t for 0 ≤ t ≤ 10; then compare the results with the plot obtained in part a.

Figure P27.

Transcribed Image Text:

Jus Vs if vs > 0 UL if vs < 0