The thermal voltage, Vt, is given by kT/q where:
What is the thermal voltage at Room Temperature (25oC)?
At what temperature is the thermal voltage actually equal to the 25mV that we generally use when working problems.
How much does the thermal voltage change per 1oC change in temperature?
What is the basic functional relationship between the collector current in a BJT transistor and the base-emitter voltage?
There is a Rule of Thumb that states that the collector current of a BJT will increase by an order of magnitude for every 60mV increase in the base-emitter voltage. Derive this relationship. At what temperature is this Rule of Thumb actually true? What is the actual change in voltage needed to obtain an order of magnitude increase in current?
Using the Rule of Thumb that states that the collector current of a BJT will increase by an order of magnitude for every 60mV increase in the base-emitter voltage, by how much will the base emitter voltage drop if the collector current drops from 123mA to 45mA?
The saturation voltage, IS, for a p-n junction is a strong function of temperature. As a useful Rule of Thumb, it doubles for every 5oC increase in the junction temperature. Using this relationship, how much does the temperature need to increase by in order to get an order of magnitude increase in the collector current of a BJT if everything else is held fixed?
The transconductance of a BJT transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the transconductance of a transistor in terms of its DC operating point values.
The input resistance of a BJT transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the input resistance of a transistor in terms of its DC operating point values.
The emitter resistance of a BJT transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the emitter resistance of a transistor in terms of its DC operating point values.
Describe the Early Effect. In particular, how does the Early Effect manifest itself on the plot of collector current versus collector-emitter voltage for a particular BJT transistor? How is the Early Voltage determined on such a plot? How can the basic BJT transistor equation be augmented to incorporate the Early Effect?
The output resistance of a BJT transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the output resistance of a transistor in terms of its Early Voltage.
What is the basic functional relationship between the drain current in an enhancement mode FET and the gate-source voltage?
The transconductance of a FET transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the transconductance of a transistor in terms of its DC operating point values.
Describe the Early Effect. In particular, how does the Early Effect manifest itself on the plot of drain current versus gate-source voltage for a particular FET transistor? How is the Early Voltage determined on such a plot? How can the basic FET transistor equation be augmented to incorporate the Early Effect?
The output resistance of a FET transistor is the ratio of the changes in what two parameters? Derive the equation which expresses the output resistance of a transistor in terms of its Early Voltage.