# /docs/design-notes

Design decisions and technical documentation for your KiCad project.

## Purpose
This directory contains technical documentation that explains the design decisions, trade-offs, and engineering rationale behind your KiCad project.

## Document Types
- **Design Requirements**: Project specifications and constraints
- **Architecture Overview**: High-level system design
- **Circuit Analysis**: Detailed circuit explanations
- **Component Selection**: Why specific components were chosen
- **Design Trade-offs**: Alternative approaches considered
- **Simulation Results**: SPICE analysis and verification
- **Design Reviews**: Peer review notes and feedback

## Recommended Files
```
design-notes/
├── requirements.md              # Project requirements and specifications
├── architecture.md              # System architecture overview
├── power-design.md              # Power supply design notes
├── signal-integrity.md          # High-speed design considerations
├── component-selection.md       # Component choice rationale
├── thermal-analysis.md          # Thermal design considerations
├── emc-considerations.md        # EMC/EMI design notes
├── design-reviews/              # Review meeting notes
│   ├── review-001-schematic.md
│   ├── review-002-layout.md
│   └── review-003-final.md
└── simulations/                 # Simulation results and analysis
    ├── power-analysis.md
    ├── signal-timing.md
    └── thermal-simulation.md
```

## Design Requirements Template
Document your project requirements:
- **Functional Requirements**: What the system must do
- **Performance Requirements**: Speed, accuracy, efficiency
- **Environmental Requirements**: Temperature, humidity, vibration
- **Regulatory Requirements**: Safety, EMC, certifications
- **Cost Constraints**: Target BOM cost and volumes
- **Size Constraints**: Physical dimensions and weight
- **Interface Requirements**: Connectors, protocols, voltages

## Architecture Documentation
Describe your system architecture:
- **Block Diagram**: High-level system overview
- **Signal Flow**: How data/signals move through system
- **Power Distribution**: Power supply architecture
- **Interface Definitions**: External connections
- **Key Components**: Major ICs and their roles
- **Design Partitioning**: How functionality is divided

## Component Selection Notes
Document why components were chosen:
- **Requirements**: What the component needs to do
- **Alternatives Considered**: Other options evaluated
- **Selection Criteria**: Performance, cost, availability
- **Trade-offs**: Compromises made
- **Supplier Information**: Primary and alternate sources
- **Lifecycle Considerations**: Obsolescence risk

## Design Review Process
Document design reviews:
- **Review Objectives**: What was being reviewed
- **Participants**: Who attended the review
- **Findings**: Issues and concerns identified
- **Action Items**: Required changes and improvements
- **Sign-off**: Approval status and next steps

## Simulation and Analysis
Document analysis work:
- **Simulation Setup**: Tools and models used
- **Test Conditions**: Operating conditions simulated
- **Results**: Key findings and measurements
- **Interpretation**: What the results mean
- **Design Impact**: How results influenced design
- **Verification**: How simulation was validated

## Best Practices
- Write for future maintainers (including yourself)
- Include diagrams and schematics where helpful
- Reference specific component datasheets
- Document assumptions and limitations
- Update notes when design changes
- Use consistent formatting and terminology
- Include revision history for major changes
