Reconstruction and Filtering: Zero-Order Hold, Images, and Analog Smoothing: Inputs and Outputs

Inputs and outputs contract

Inputs and Outputs for Reconstruction and Filtering: Zero-Order Hold, Images, and Analog Smoothing is anchored on Passband ripple, image rejection at Fs multiples, group delay budget, and end-to-end in-band EVM/SNR after reconstruction filtering.. Convert observations into mechanism-backed and owner-bound actions.

INPUTS
  - operating context and aggressor profile
  - measurement setup and calibration state
  - model assumptions and validity bounds
  - boundary contracts and ownership map

OUTPUTS
  - evidence-backed mechanism classification
  - owner-signed bounded mitigation proposal
  - validation matrix and rollback trigger
  - release recommendation

Ownership split

OWNERSHIP LAYERS - Reconstruction and Filtering: Zero-Order Hold, Images, and Analog Smoothing

+----------------------+--------------------------------+--------------------------------+
| Team                 | Primary responsibility         | Closure artifact               |
+----------------------+--------------------------------+--------------------------------+
| signal-chain architect | mechanism and margin ownership  | design rationale + constraints |
| analog front-end designer | integration and runtime behavior | contract + telemetry evidence  |
| system modeling owner | bench closure and rollout gates | stress matrix + signoff memo   |
+----------------------+--------------------------------+--------------------------------+

Analog deep dive

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

Concept diagram

DAC OUTPUT CHAIN

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

Metric graph

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.

Interface contract detail

Inputs should include setup assumptions, operating point, and aggressor profile.

Outputs should include one proving artifact and one owner-signed action.