7.3.1. Components and Device Characteristics

Try these first

1. 1.

   Describe the three regions of a BJT.

   Hint

   Think about the structure of the BJT.

2. 2.

   What does it mean for a junction to be forward biased?

   Hint

   Consider how voltage affects current flow.

3. 3.

   What should the biasing condition be for junction-1 in a BJT?

   • Reverse biased
   • Forward biased
   • Neither

   Hint

   Think about how current flows through a junction.

4. 4.

   True or False: In a reverse-biased BJT, there is no current flow at all.

   • True
   • False

   Hint

   Consider from the perspective of thermal energy and minority carrier dynamics.

5. 5.

   Given a BJT with a forward voltage of 0.7V and a reverse saturation current of 1μA, calculate the current flowing through the base-emitter junction.

   Hint

   Use the exponential relation to calculate.

6. 6.

   If the doping concentrations of the emitter, base, and collector are 10^20 cm^-3, 10^15 cm^-3, and 10^18 cm^-3 respectively, analyze how these concentrations will affect current flow in different bias conditions.

   Hint

   Think critically about how carrier concentration affects mobility.