EDA Research Skill

Source and select components for electronics projects.

Auto-Activation Triggers

This skill activates when:

• User asks to "find a component", "search for", "source"
• User asks about component specifications or comparisons
• User mentions LCSC, datasheets, or part numbers
• User asks "what MCU/regulator/sensor should I use"
• Project has

  design-constraints.json

  but missing component selections

Context Requirements

Requires:

• docs/design-constraints.json

  (or prompt user for requirements)

• docs/project-spec.md

  (optional, for context)

Produces:

• docs/component-selections.md

  - Human-readable selection log

• docs/bom-draft.json

  - Machine-readable BOM

• datasheets/*.pdf

  - Downloaded datasheets for selected components

Workflow

1. Load Context

Read existing project constraints:

@docs/design-constraints.json
@docs/project-spec.md
@docs/component-selections.md (if exists)

If constraints missing, ask user for minimum requirements:

• What does this component need to do?
• Key specifications (voltage, current, package)?
• Budget constraints?

2. Understand Requirements

For the target component role, identify:

• Critical specifications (must-have)
• Preferred specifications (nice-to-have)
• Package preferences (SMD size, through-hole)
• Any specific brands or series to consider/avoid

2.5 Check Architecture Constraints

Before searching, review

design-constraints.json

• Power topology: LDO vs buck decision already made in architect phase
• Thermal budget: Max watts for this role (check

  thermal.hotComponents

  )
• DFM targets: Assembly method affects package choice
• Board layers: May affect component density

For power components, see

reference/REGULATOR-SELECTION.md

reference/PASSIVE-SELECTION.md

reference/DECOUPLING-STRATEGY.md

3. Research Options

Use web search to understand:

• Common solutions for this application
• Recommended parts from reference designs
• Known issues or considerations
• Alternative approaches

4. Search JLC

Use

mcp__jlc__component_search

• Search with specific parameters
• Filter by stock availability
• Note pricing at target quantity
• Check for "Basic" parts (lower assembly fee at JLCPCB)

5. Analyze Candidates

For top 3-5 options:

• Download/fetch datasheets
• Extract key specifications
• Check application circuits
• Note layout requirements
• Identify any gotchas

5.5 Validate Against Constraints

Before presenting options, verify each candidate:

Thermal validation:

P_dissipation = (calculated from datasheet)
Thermal budget = (from design-constraints.json)
✓ P_dissipation < Thermal budget

Assembly compatibility:

• Hand assembly → 0603/0805 minimum, no fine-pitch
• Reflow → 0402+ OK
• Turnkey → Check JLCPCB availability

Architecture compliance:

• Meets LDO/buck decision from architect phase
• Noise specs OK for rail type (analog vs digital)
• Efficiency acceptable for battery applications

Flag any candidates that fail validation with specific concerns.

6. Present Comparison

Create a comparison table:

Include recommendation with rationale.

7. Confirm Selection

• Get user confirmation
• Document selection with rationale
• Update constraint file
• Save datasheet

8. Validate Symbol (After library_fetch)

When fetching online components with

mcp__jlc__library_fetch

validation_data

Quick checks:

pin_pad_count_match

true

has_power_pins

true

has_ground_pins

true

Common issues:

• QFN/BGA packages often have exposed thermal pads (EP) not included in symbol
• Pin electrical types may be incorrect (power pins marked as passive)
• Pin names may not match datasheet

Fixing with library_fix:

Use

mcp__jlc__library_fix

mcp__jlc__library_fix lcsc_id="C#####" corrections='{
  "pins": [
    { "action": "add", "number": "EP", "name": "GND", "type": "passive" },
    { "action": "modify", "number": "1", "set_type": "power_in" }
  ]
}'

Correction actions:

• add

  - Add missing pin (number, name, type required)

• modify

  - Rename and/or change electrical type

• swap

  - Swap positions of two pins

• remove

  - Remove incorrect pin

Output Format

component-selections.md Entry

### [Role]: [Part Name] ([LCSC Number])

**Selected:** [Date]
**MPN:** [Manufacturer Part Number]
**Manufacturer:** [Name]
**Price:** $X.XX @ [quantity]

**Specifications:**
- Key spec 1: value
- Key spec 2: value

**Rationale:**
[Why this part was chosen over alternatives]

**Alternatives Considered:**
- [Part 2] - rejected because [reason]
- [Part 3] - rejected because [reason]

**Design Notes:**
- [Any layout or application notes from datasheet]

**Datasheet:** `datasheets/[filename].pdf`

bom-draft.json Entry

{
  "role": "regulator-3v3",
  "lcsc": "C6186",
  "mpn": "AMS1117-3.3",
  "manufacturer": "AMS",
  "description": "3.3V 1A LDO Regulator",
  "value": "3.3V",
  "footprint": "SOT-223",
  "quantity": 1,
  "unitPrice": 0.04,
  "extendedPrice": 0.04,
  "category": "power",
  "basic": true
}

Component Role Categories

See

reference/COMPONENT-CATEGORIES.md

Common roles:

• mcu

  - Main microcontroller

• regulator-Xv

  - Voltage regulators

• crystal

  - Oscillators/crystals

• connector-*

  - Various connectors

• esd-*

  - ESD protection

• decoupling-*

  - Bypass/bulk capacitors

• led-*

  - Indicator LEDs

• sensor-*

  - Various sensors

Guidelines

• Prefer JLCPCB "Basic" parts when suitable (lower assembly cost)
• Check stock levels - avoid parts with < 100 in stock
• Consider package size vs hand soldering capability
• Note lead times for non-stock items
• Always document why a part was chosen
• Download datasheets for all selected components
• Identify 1-2 alternatives for critical components (see

  reference/COMPONENT-ALTERNATIVES.md

  )
• Validate thermal before confirming power components
• Check architecture decisions from design-constraints.json before selecting

Reference Documents

REGULATOR-SELECTION.md

DECOUPLING-STRATEGY.md

PASSIVE-SELECTION.md

COMPONENT-ALTERNATIVES.md

DATASHEET-ANALYSIS.md

COMPONENT-CATEGORIES.md

JLC-SEARCH-TIPS.md

Next Steps

After component selection is complete:

1. Run

   /eda-source

   for remaining components
2. When all components selected, run

   /eda-schematic

3. Update

   design-constraints.json

   stage to "schematic"