7.4. Basic Structure of BJT

Try these first

1. 1.

   What are the three layers of the BJT?

   Hint

   Think of the acronym 'EBC'.

2. 2.

   What is the purpose of the emitter?

   Hint

   What happens at the start of the current flow?

3. 3.

   What is the main function of the base in a BJT?

   • To inject carriers
   • To control the flow of current
   • To collect current

   Hint

   What is the layer's primary role?

4. 4.

   True or False: The emitter is reverse-biased in normal operation.

   • True
   • False

   Hint

   Recalling the biasing conditions can clarify this.

5. 5.

   If the base-emitter voltage is increased, describe how the collector current will be affected in a BJT and why.

   Hint

   Think about how the exponential relationship in the current equation relates to the applied voltage.

6. 6.

   Given a BJT with specific doping concentrations, calculate the expected multiplication factor for the carrier concentration in the base as the emitter junction is forward-biased.

   Hint

   Relate this to how the forward bias influences carrier flow through the base region.