Analog for Digital Engineers · All levels

Static and Dynamic DAC Metrics: INL/DNL, Glitch, and SFDR: Design Space

Design Space for Static and Dynamic DAC Metrics: INL/DNL, Glitch, and SFDR.

Design space exploration

For Static and Dynamic DAC Metrics: INL/DNL, Glitch, and SFDR, teams balance performance, robustness, and debug cost.

Option A - conservative

  • Conservative margins: helps predictable closure

  • Risk: higher area/power

  • Validate with: first-silicon risk reduction

Option B - balanced

  • Balanced optimization: helps good PPA and robustness

  • Risk: review-heavy

  • Validate with: production programs

Option C - aggressive

  • Aggressive performance: helps best headline metrics

  • Risk: narrow guard-bands

  • Validate with: mature modeling and calibration

Option D - observability-first

  • Observability-first: helps faster debug

  • Risk: more instrumentation cost

  • Validate with: complex bring-up environments

diagram
DESIGN SPACE - Static and Dynamic DAC Metrics: INL/DNL, Glitch, and SFDR
performance <-> robustness <-> implementation cost <-> debug observability

Design pitfalls

  • Optimizing one metric while hiding dominant secondary failure modes.

  • Mixing architecture and implementation changes in one debug iteration.

Analog deep dive

DAC closure needs both static transfer quality and dynamic glitch/spectral discipline.

Concept diagram

diagram
DAC OUTPUT CHAIN

code mapping -> switching network -> output path -> reconstruction filter

Metric graph

diagram
DAC RISK MIX

major-carry glitches     █████
settling residuals       ████
image leakage            ███

Metrics and artifacts to collect

  • INL/DNL sweep package

  • glitch energy and settling trend

  • SFDR/THD versus output frequency

  • reconstruction filter compliance

Mini case study

Good static linearity masked dynamic spur failures driven by switching asymmetry and insufficient reconstruction margin.

Debug branches

  • Tie static transfer plots to dynamic spectral outcomes.

  • Inspect major-carry behavior separately from small-step transitions.

  • Validate output path with realistic load and package parasitics.

Senior review question

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

Key takeaways

  • Tie every analog claim to one measurable metric and one proving artifact.

  • Prefer minimal reversible mitigations with explicit owner and rollback criteria.

Common pitfalls

  • Treating all noise as one scalar instead of path and frequency dependent behavior.

  • Changing multiple analog knobs at once and losing causality.

  • Declaring closure from nominal behavior without stress replay evidence.

Principal analog review addendum

Static and Dynamic DAC Metrics: INL/DNL, Glitch, and SFDR should be reviewed as an end-to-end execution problem spanning architecture, implementation, and integration.

Use DNL/INL limits, missing-code incidence, glitch impulse area at major carries, and SFDR/THD across output frequency sweep. as the trigger metric and Measurement plan connecting static sweep plots (INL/DNL) to dynamic FFT results (SFDR/THD/glitch-sensitive tones). as the proof contract.

DAC closure requires both static linearity discipline and dynamic switching-spectrum control. Durable closure comes from explicit assumptions and owner accountability.