7. Overview of Bipolar Junction Transistors (BJTs)

Try these first

1. 1.

   What is a BJT?

   Hint

   Think about its role in amplifying signals.

2. 2.

   Name the two types of BJTs.

   Hint

   Recall the majority carriers for each type.

3. 3.

   What type of transistor has holes as the majority carriers?

   • NPN
   • PNP
   • None of the above

   Hint

   Remember which type stands for 'Positive Negative Positive'.

4. 4.

   True or False: BJTs are voltage-controlled devices.

   • True
   • False

   Hint

   Think about the differences between BJTs and MOSFETs.

5. 5.

   Given a BJT with a β of 100 and a base current of 10 µA, determine the collector current.

   Hint

   Apply the current gain formula.

6. 6.

   Analyze how thermal runaway could affect a BJT in a high-power circuit. What preventative measures could be taken?

   Hint

   Think about the physical behaviors with increasing temperature effects.