9.5.1. Equivalent Circuit Using BJT

Try these first

1. 1.

   What does BJT stand for?

   Hint

   Think about how the transistor operates with two types of charge carriers.

2. 2.

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

   Hint

   This current acts as an input to influence a larger output current.

3. 3.

   What is β in a BJT?

   • The collector current
   • Base current to collector current gain
   • Emitter current to collector current gain

   Hint

   It is a crucial parameter in understanding transistor amplification.

4. 4.

   True or False: The I-V characteristic of a BJT is a linear relationship.

   • True
   • False

   Hint

   Think about the curves of current versus voltage practically observed.

5. 5.

   A circuit contains a BJT with β = 200 and the base current is measured at 5 mA. Calculate the collector current and describe what happens when the transistor enters saturation.

   Hint

   Consider the relationship between how the base fosters the increase in collector current until a threshold.

6. 6.

   Design a simple BJT amplifier circuit with specified resistances and supply voltage. Calculate the expected output based on given parameters and check if it stays in the active region.

   Hint

   Reflect on what limits your output and how to keep the circuit functioning optimally.