Noise types in transistors: Which of the following types of noise does not occur in transistors?
Correct Answer: Resistance noise
Introduction / Context:Electronic devices generate different kinds of noise based on their operating principles. Transistors in particular exhibit characteristic noise types important in amplifier design.
Given Data / Assumptions:
- We focus specifically on transistor noise sources.
- Common transistor noise types: shot noise, flicker (1/f) noise, partition noise.
Concept / Approach:
Transistors generate noise associated with random carrier movements across junctions and bias regions. Resistance noise (thermal noise) is associated with passive resistors, not active semiconductor devices like transistors.
Step-by-Step Solution:
Shot noise: due to random carrier arrivals at junction.Flicker noise: increases at low frequencies, common in transistors.Partition noise: occurs when current divides between transistor junctions.Resistance noise: belongs to resistors, not transistors.Verification / Alternative check:
Device noise analysis confirms resistors produce Johnson noise, while transistors exhibit shot, flicker, and partition noise.
Why Other Options Are Wrong:
- Shot, flicker, and partition noise are intrinsic to transistor operation.
- Avalanche noise also appears in breakdown conditions of semiconductors.
Common Pitfalls:
- Confusing thermal noise of resistors with transistor-specific noise.
Final Answer:
Resistance noise