The circuit in Fig. P4.23 utilizes three identical diodes having IS = 10−14 A. Find the value of the current I required to obtain an output voltage VO = 2.0 V. If a current of 1 mA is drawn away from the output terminal by a load, what is the change in output voltage?

Since we have identical diodes we can use the equation:

And replacing we have:

Since we know that 1 mA is drawn away from the output then the real value for I would be

And for this case the value for would be:

And the output votage on this case would be:

And the net change in the output voltage would be:

Explanation:

For this case we have the figure attached illustrating the problem

We know that the equation for the current in a diode id given by:

For this case the voltage across the 3 diode in series needs to be 2 V, and we can find the voltage on each diode and each voltage is the same v for each diode, so then:

Since we have identical diodes we can use the equation:

And replacing we have:

Since we know that 1 mA is drawn away from the output then the real value for I would be

And for this case the value for would be:

And the output votage on this case would be:

And the net change in the output voltage would be:

thermal energy is the answer