ERC/DRC Fix Execution Plan
Goal
Resolve all ERC and DRC violations in the Pulse Induction metal detector PCB project, with emphasis on grounding strategy, high-current path robustness, analog/power isolation, placement improvements, and power integrity. Only export manufacturing outputs after validation shows zero critical or high-severity issues.
Priorities
- Ground segregation with a single star-ground point at the 12 V input.
- Minimum 3 mm trace widths for coil-current and power-switching paths.
- Clear analog-to-power clearance and isolation.
- Arduino Nano placed centrally as a functional boundary/buffer between analog and power sections.
- Verify and place local 100 nF decoupling at active devices plus per-domain bulk capacitors.
- Rerun ERC/DRC and do not export until zero critical/high-severity issues remain.
High-Level Execution Phases
1. Baseline review and issue triage
- Run the full ERC/DRC review and collect all current violations.
- Group findings by category: connectivity/ERC, placement/layout, routing/clearance, missing decoupling, width/rules, and manufacturability.
- Rank issues by criticality, fixing blocking electrical and safety/power issues first.
2. Grounding architecture cleanup
- Identify all analog, digital/control, and power-return current paths.
- Rework the grounding scheme so analog and switching/high-current grounds remain segregated.
- Define one intentional star-ground tie point at the 12 V input return.
- Remove accidental alternate return connections or copper paths that defeat the star-ground strategy.
- Verify sensitive analog reference/sense paths do not share noisy switching return current loops.
3. High-current path rule enforcement
- Identify the coil-drive loop and all power-switching nets/components.
- Apply or tighten layout rules so these paths use a minimum 3 mm trace width wherever physically possible.
- Inspect bottlenecks at pads, vias, connectors, and neck-down regions.
- Re-route or reposition parts as needed to preserve current capacity and reduce loop resistance/inductance.
4. Analog vs. power section isolation
- Define a clear physical and routing boundary between the analog front end and the power-switching section.
- Increase spacing/clearance between noisy switching nodes and analog nets/components.
- Keep switching loops compact and away from amplifier, comparator, ADC, and reference circuitry.
- Review copper pours and return paths so analog areas are not contaminated by switching-current coupling.
5. Functional placement refinement
- Reposition the Arduino Nano to a central location so it acts as a practical buffer/interface between analog and power sections.
- Cluster analog components close to the analog signal chain.
- Cluster high-current/power-switching parts close to the input/power side and coil path.
- Reposition connectors and support passives as needed to reduce crossing nets and long noisy runs.
6. Decoupling and bulk capacitance verification
- Check every IC/module for a local 100 nF decoupling capacitor placed close to its supply pins.
- Add or move missing/local decoupling capacitors as required.
- Verify each power domain has appropriate bulk capacitance near its entry/load concentration.
- Distinguish domains such as raw 12 V input, switched power/coil driver supply, Arduino/digital rail, and analog rail.
- Confirm decoupling and bulk caps have short return paths into the intended ground domain.
7. Rule cleanup and violation closure
- Resolve remaining ERC items such as floating pins, mislabeled nets, missing power intent, or unconnected passive support parts.
- Resolve remaining DRC items such as airwires, clearance violations, width violations, overlaps, invalid layer usage, and missing footprints/models if relevant.
- Re-run checks iteratively after each major correction batch instead of waiting until the end.
8. Final validation gate
- Run ERC and DRC again after all corrective actions.
- Confirm there are zero critical or high-severity violations.
- If any critical/high issues remain, return to corrective steps and do not export.
- Optionally review medium/low severity items for manufacturability and robustness before release.
9. Release outputs
- Only after the validation gate passes:
- Export Gerber
- Export BOM
- Export Pick-and-Place
- Perform a final sanity review of outputs before handoff/fabrication.
Suggested Working Order
- Full review snapshot
- Ground/star-point restructuring
- 3 mm power/coil rule setup and routing fixes
- Analog/power separation improvements
- Arduino Nano placement refinement
- Decoupling and bulk capacitor verification
- Remaining ERC/DRC cleanup
- Final validation
- Manufacturing exports
Success Criteria
- Single intentional star-ground connection at 12 V input.
- Coil/power-switching paths meet 3 mm minimum width target.
- Analog circuitry is physically and electrically isolated from noisy power switching.
- Arduino Nano is centrally placed to buffer analog and power sections.
- Local 100 nF decoupling exists at each active device, with per-domain bulk capacitance verified.
- ERC/DRC report shows zero critical and zero high-severity violations before export.