7.6. Current Expressions

Try these first

1. 1.

   What are the three regions of a BJT?

   Hint

   Think of the parts involved in BJT operation.

2. 2.

   What is the purpose of the base region in a BJT?

   Hint

   Consider the controlling aspect of the BJT.

3. 3.

   What does a BJT utilize for its operation?

   • Only electrons
   • Only holes
   • Both electrons and holes

   Hint

   Think about the type of charge carriers mentioned.

4. 4.

   True or False: The base-emitter junction is typically reverse-biased in normal operations.

   • True
   • False

   Hint

   Recall the biasing conditions of the junctions.

5. 5.

   Consider a BJT with a forward-biased base-emitter junction of 0.7V, derive the current using the diode equation.

   Hint

   Remember the thermal voltage at room temperature is approximately 25mV.

6. 6.

   You have a BJT with a known collector current of 5mA and a beta (current gain) of 100. Calculate the base current.

   Hint

   Focus on relationships between different currents in the BJT.