The output impedance of an emitter follower can be reduced by using
A) a large load resistor.
B) negative feedback.
C) positive feedback.
D) a large input resistor.

Question

Quizplus · Accepted Answer

Negative feedback can be used to reduce the output impedance of an emitter follower. This can be achieved by connecting the output of the emitter follower to the inverting input of an operational amplifier and using a feedback resistor to connect the output to the input. This creates a closed loop system that stabilizes the output impedance and reduces the effect of variations in the load impedance. A large load resistor (choice A) can actually increase the output impedance, while positive feedback (choice C) and a large input resistor (choice D) do not have a significant effect on output impedance reduction.

The Output Impedance of an Emitter Follower Can Be Reduced