Package Effects on AMS: Review Checklist

Review checklist

Review Checklist for Package Effects on AMS focuses on package-induced jitter, return-path discontinuity flags, board bring-up instability. The goal is to connect observed symptom to boundary mechanism, ownership, and signoff risk.

• Boundary assumptions are versioned and signed.

• Mode matrix (power/clock/reset/stress) is explicit.

• Physical context (floorplan/package/power) is included where relevant.

• Metric and artifact references are reproducible.

• Waivers have owner, expiry, and mitigation.

• Owners signed: package engineer, board SI owner, SerDes/PLL owner.

Sign-off ownership

OWNERSHIP MAP — Package Effects on AMS

artifact                  owner
----------------------    -----------------------------
integration artifact    package engineer
implementation artifact board SI owner
signoff artifact        SerDes/PLL owner

Every boundary issue needs a named owner before fixes start.

AMS deep dive

AMS signoff is a combined noise, IR, timing, and package decision.

Concept diagram

BOUNDARY SIGNOFF

noise + IR + package + timing -> release decision

Metric graph

RISK DASHBOARD

open blockers █████
waivers       ███

Reports and artifacts

• supply ripple spectrum

• IR around analog islands

• package PI summary

• release dashboard

Mini case study

IR hotspot at analog island caused jitter spikes only under burst traffic.

Debug branches

• Correlate droop and jitter

• Check package return path

• Validate mode-specific activity profile

Senior review question

Ask: what boundary condition proves this topic is actually closed?

Key takeaways

• State boundary, mode, and evidence tag with every claim.

• Always align analog, digital, and physical owners before signoff decisions.

Common pitfalls

• Fixing averages while tails still fail.

• Skipping package/supply evidence in jitter or SerDes issues.

• Shipping with waivers that lack owner and expiration criteria.

Principal AMS review addendum

Bump assignments, return-current loops, and package resonances alter reference quality and high-speed channel behavior seen by mixed-signal interfaces.

Metric: package-induced jitter, return-path discontinuity flags, board bring-up instability