Diodes, transistors (including BJT) and current mirrors
Show all logic/work/sources leading up to the conclusions drawn for each problem.
1. One simplified model of a forward conducting Silicon diode's behaviour is to consider the diode to be equivalent to a series combination of a low resistance, a 0.7V fixed voltage source, and an ideal diode. Explain how this model is a reasonable approximation in terms of the true I-V relationship for a practical diode. What impact does the operating environment have on the true I-V relationship, and how can we account for this effect in the model? Describe the practical application of this environmental effect.
2. What effect do internal capacitances in the transistor model have on practical performance of a real system? How would you use these model values to predict system performance?
3. How are mutual transconductance, β and α of a BJT transistor related to each other? What role do these parameters play in circuit design?
4. Describe the operation of a current mirror and illustrate how one might be used.