Mitigation options trade margin, power, area, and schedule confidence.
+------------------+----------------+----------------+----------------+
| Approach | Strength | Weakness | Best when |
+------------------+----------------+----------------+----------------+
| Conservative | robust | more overhead | new tapeout |
| Balanced | practical | needs rigor | mature flow |
| Aggressive | faster | high regressions | late stage |
| Architectural | durable | slow loop | recurring issue |
+------------------+----------------+----------------+----------------+Choose the smallest change that proves mechanism and preserves system margins.
Treating all AMS problems as analog-only
Skipping package and power evidence
AMS EVIDENCE MATRIX — Analog Supply Noise
+-------------------+------------------------+--------------------------+-------------------------+
| Evidence | Tells you | Does not prove | Next action |
+-------------------+------------------------+--------------------------+-------------------------+
| Waveform/log pair | sequence behavior | physical root cause | correlate with signoff |
| Signoff report | metric movement | contract correctness | audit assumptions |
| Floorplan view | physical proximity | dynamic mode behavior | run stress mode |
| Firmware trace | state progression | analog quality | combine with lab data |
| Dashboard summary | closure status | single-failure mechanism | inspect raw artifacts |
+-------------------+------------------------+--------------------------+-------------------------+AMS signoff is a combined noise, IR, timing, and package decision.
BOUNDARY SIGNOFF
noise + IR + package + timing -> release decisionRISK DASHBOARD
open blockers █████
waivers ███supply ripple spectrum
IR around analog islands
package PI summary
release dashboard
IR hotspot at analog island caused jitter spikes only under burst traffic.
Correlate droop and jitter
Check package return path
Validate mode-specific activity profile
Ask: what boundary condition proves this topic is actually closed?
State boundary, mode, and evidence tag with every claim.
Always align analog, digital, and physical owners before signoff decisions.
Fixing averages while tails still fail.
Skipping package/supply evidence in jitter or SerDes issues.
Shipping with waivers that lack owner and expiration criteria.
Switching current bursts from digital domains couple through shared impedance and package parasitics, modulating analog supply quality and phase noise.
Metric: supply ripple, spur coupling, analog performance degradation
This content block can't be displayed here.
Block type: unknown
This content block can't be displayed here.
Block type: unknown
This content block can't be displayed here.
Block type: unknown