Noise & Signal Integrity

Section goal

Thermal and 1/f noise origins, supply coupling and PSRR limits, sampling alias mechanisms, and jitter/phase-noise impacts that bound analog front-end and mixed-signal link performance.

How to study this section

1. Start with each topic hub and restate the mechanism in your own words.

2. Use reports and debug pages to classify first failing boundaries.

3. Practice worked examples and interview drills under fixed setup metadata.

4. Close with checklist and execution impact before signoff claims.

Topics

1. thermal-and-flicker-noise/ - Thermal and Flicker Noise Sources in Real Circuits

2. power-supply-noise-and-psrr/ - Supply Noise Coupling Paths and PSRR Across Frequency

3. sampling-and-aliasing/ - Sampling, Spectral Folding, and Anti-Alias Filter Strategy

4. jitter-and-phase-noise/ - Jitter vs Phase Noise and Link/Converter Sensitivity

Related topics

• Analog for Digital course hub

Analog deep dive

Noise and SI closure is achieved by frequency-aware path analysis, not one-number guard-bands.

Concept diagram

NOISE PATH VIEW

source -> transfer function -> victim sensitivity -> system margin

Metric graph

NOISE CLOSURE

path unknown             ██████
path classified          █████████
validated mitigations    ███████

Metrics and artifacts to collect

• white/1-f noise decomposition

• PSRR versus frequency profile

• alias-folding sensitivity map

• phase-noise to jitter integration summary

Mini case study

A broadband spur issue persisted until teams modeled package and return-path coupling instead of relying on low-frequency PSRR numbers.

Debug branches

• Classify deterministic versus random contributors first.

• Map dominant transfer path before adding generic filtering.

• Use operating-mode-specific aggressor profiles in validation.

Senior review question

Ask: which source-path-victim boundary failed first, and which artifact proves it reproducibly?