Noise Analysis

Understanding and minimizing electronic noise for high-performance analog circuits.

Electronic noise limits the minimum signal level a circuit can process. Understanding noise sources and how to minimize them is critical for sensitive analog designs like audio preamps and sensor interfaces.

Objectives

  • Identify thermal, shot, and flicker noise sources
  • Calculate noise voltage and current densities
  • Determine signal-to-noise ratio and noise figure
  • Design low-noise amplifier input stages
  • Apply noise reduction techniques

Key Takeaways

  • Thermal noise is proportional to √(resistance × bandwidth)
  • Shot noise depends on DC current
  • 1/f noise dominates at low frequencies
  • Input stage noise contribution is most critical