Table of Contents
- 1. Product Overview
- 2. Technical Parameter Deep Objective Interpretation
- 2.1 Lifecycle Phase Attribute
- 2.2 Temporal Attributes
- 3. Grading System Explanation This document itself represents a grade or tier within a version control system. The grading is sequential and integer-based (e.g., Revision 1, Revision 2, etc.). Higher revision numbers generally indicate later points in time and incorporate more recent updates, corrections, or enhancements. There is no sub-grading (like 2.1, 2.2) indicated here, suggesting a linear revision history. 4. Performance Curve Analysis Performance in this context refers to the document's role in the engineering lifecycle. A 'revision' curve would show stability and maturity increasing with each revision number, while the rate of change might decrease as the product definition solidifies. The 'Forever' expiration creates a flat line for validity, indicating no planned obsolescence for this specific document version. 5. Mechanical and Packaging Information
- 6. Soldering and Assembly Guidelines
- 7. Packaging and Ordering Information
- 8. Application Suggestions
- 9. Technical Comparison
- 10. Frequently Asked Questions
- 11. Practical Case Studies
- 12. Principle Introduction
- 13. Development Trends
1. Product Overview
This document pertains to a specific lifecycle phase of a technical component or product. The primary information conveyed is the establishment of a revision state, designated as 'Revision 2'. This indicates a formal update or modification from a previous version. The release of this revision is timestamped as December 11, 2014, at 18:38:19. A critical characteristic defined here is the 'Expired Period', which is set to 'Forever'. This signifies that this particular revision does not have a predefined end-of-life date and is intended to remain valid indefinitely, barring any future superseding revisions. This is common for foundational documentation or specifications that form a permanent reference point.
2. Technical Parameter Deep Objective Interpretation
While specific electrical, optical, or mechanical parameters are not detailed in the provided content, the core technical parameters of this document are its metadata attributes.
2.1 Lifecycle Phase Attribute
The 'LifecyclePhase: Revision' is a key parameter in product data management. 'Revision 2' specifies the version control status. It implies that the associated technical data has undergone at least one round of review and change, making it more mature and reliable than an initial draft (Revision 0 or 1). Engineers must ensure they are working with the correct revision to avoid discrepancies.
2.2 Temporal Attributes
The 'Release Date' (2014-12-11 18:38:19.0) is a precise timestamp for version control. The 'Expired Period: Forever' is a definitive statement on the document's validity. In technical contexts, 'Forever' typically means the document is valid for the lifetime of the product lineage it describes or until explicitly replaced by a new revision. It does not imply the underlying technology is static, but that this snapshot of its definition is permanently archived.
3. Grading System Explanation
This document itself represents a grade or tier within a version control system. The grading is sequential and integer-based (e.g., Revision 1, Revision 2, etc.). Higher revision numbers generally indicate later points in time and incorporate more recent updates, corrections, or enhancements. There is no sub-grading (like 2.1, 2.2) indicated here, suggesting a linear revision history.
4. Performance Curve Analysis
Performance in this context refers to the document's role in the engineering lifecycle. A 'revision' curve would show stability and maturity increasing with each revision number, while the rate of change might decrease as the product definition solidifies. The 'Forever' expiration creates a flat line for validity, indicating no planned obsolescence for this specific document version.
5. Mechanical and Packaging Information
This section is not applicable to the provided document content, which deals with metadata rather than physical product characteristics. For a component datasheet, this would include detailed dimensional drawings, package outlines, pad layouts, and polarity markings.
6. Soldering and Assembly Guidelines
This section is not applicable to the provided document content. For a hardware component, this would provide critical instructions on reflow soldering profiles (preheat, soak, reflow, cooling temperatures and times), handling precautions (ESD, moisture sensitivity level), and recommended storage conditions (temperature, humidity).
7. Packaging and Ordering Information
The 'packaging' of this document is its digital format and revision labeling. The ordering information is implied by the revision number; users must specify 'Revision 2' when referencing or requesting this document. A complete datasheet would detail reel/tube packaging specifications, quantity per package, labeling conventions including part number and revision code, and the full model number naming rule that includes all key parameters.
8. Application Suggestions
This document is applied in formal engineering and quality assurance processes. Its primary application scenarios include:
- Design Freeze: Serves as the definitive reference for all specifications agreed upon at a project milestone.
- Manufacturing Reference: Used on production lines to ensure the built product matches the approved design (Revision 2).
- Audit and Compliance: Provides evidence of a controlled and documented design state for regulatory or customer audits.
- Change Management: Acts as the baseline against which future proposed changes (Revision 3) are evaluated.
Design Considerations: When integrating a component defined by a 'Revision 2, Forever' document, designers must verify if any subsequent revisions exist that might offer improved performance or corrected errata. The 'Forever' status provides long-term stability for legacy or long-lifecycle products.
9. Technical Comparison
The key differentiation lies in the revision history. Compared to 'Revision 1', this version (Revision 2) offers increased accuracy, incorporates feedback, and resolves known issues from the prior version. Its 'Forever' expiration period is an advantage over documents with a fixed expiry, as it guarantees permanent availability for reference, supporting products with extended service lives. The disadvantage could be potential stagnation if it is not updated to reflect new industry standards or safety regulations.
10. Frequently Asked Questions
Q: What does 'LifecyclePhase: Revision' mean?
A: It indicates the document is in a state of being a formally released and version-controlled update. It is not a draft, prototype, or obsolete document.
Q: Does 'Expired Period: Forever' mean the product never becomes obsolete?
A: No. It means this specific document revision does not have an automatic expiration date. The physical product it describes may still be discontinued, but this record of its specification remains valid as a historical reference.
Q: The release date is 2014. Is this information still relevant?
A> The relevance depends on the context. For maintaining or repairing systems built around that time, it is absolutely critical. For new designs, a newer revision or product should be sought. The date itself is a vital parameter for traceability.
Q: How do I know if a newer revision (e.g., Revision 3) exists?
A: You must consult the official document repository or product change notices (PCNs) from the source. Always use the latest revision unless explicitly required by a project's design freeze.
11. Practical Case Studies
Case Study 1: Legacy System Maintenance
A manufacturing plant operates machinery from 2015. A critical sensor fails. The replacement part must match the original specifications. The technician consults the 'Revision 2, Released 2014' datasheet to identify the correct component, ensuring compatibility and avoiding downtime from using an incompatible newer revision.
Case Study 2: Design Documentation for Safety Certification
A company seeks safety certification for a medical device. The certifying body requires all design documents to be revision-controlled and archived. The 'Revision 2, Forever' document provides the immutable evidence needed for the audit, demonstrating controlled design processes.
12. Principle Introduction
The principle behind this document is formal configuration management and version control in engineering. It is an objective record of a product's or component's defined state at a specific point in time. The 'Revision' number enables tracking of changes. The 'Release Date' provides temporal context. The 'Expired Period' governs the document's validity within the management system. This structured approach is fundamental to ensuring consistency, quality, and traceability in complex technical projects, preventing errors caused by using incorrect or outdated information.
13. Development Trends
Objectively, the trend in technical documentation is towards digital, linked, and dynamic data. While PDFs with revision metadata remain common, there is a move to cloud-based platforms where documents are 'living' and changes are tracked automatically (like software version control with Git). The concept of a 'Forever' static PDF may evolve towards 'permanent URIs' for specific document states within a dynamic database. Furthermore, integration with Product Lifecycle Management (PLM) and Enterprise Resource Planning (ERP) systems is deepening, where document revision status directly gates manufacturing and procurement workflows. The core need for unambiguous version identification, as exemplified by this simple 'Revision 2' label, will remain constant even as the delivery mechanisms advance.
LED Specification Terminology
Complete explanation of LED technical terms
Photoelectric Performance
| Term | Unit/Representation | Simple Explanation | Why Important |
|---|---|---|---|
| Luminous Efficacy | lm/W (lumens per watt) | Light output per watt of electricity, higher means more energy efficient. | Directly determines energy efficiency grade and electricity cost. |
| Luminous Flux | lm (lumens) | Total light emitted by source, commonly called "brightness". | Determines if the light is bright enough. |
| Viewing Angle | ° (degrees), e.g., 120° | Angle where light intensity drops to half, determines beam width. | Affects illumination range and uniformity. |
| CCT (Color Temperature) | K (Kelvin), e.g., 2700K/6500K | Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool. | Determines lighting atmosphere and suitable scenarios. |
| CRI / Ra | Unitless, 0–100 | Ability to render object colors accurately, Ra≥80 is good. | Affects color authenticity, used in high-demand places like malls, museums. |
| SDCM | MacAdam ellipse steps, e.g., "5-step" | Color consistency metric, smaller steps mean more consistent color. | Ensures uniform color across same batch of LEDs. |
| Dominant Wavelength | nm (nanometers), e.g., 620nm (red) | Wavelength corresponding to color of colored LEDs. | Determines hue of red, yellow, green monochrome LEDs. |
| Spectral Distribution | Wavelength vs intensity curve | Shows intensity distribution across wavelengths. | Affects color rendering and quality. |
Electrical Parameters
| Term | Symbol | Simple Explanation | Design Considerations |
|---|---|---|---|
| Forward Voltage | Vf | Minimum voltage to turn on LED, like "starting threshold". | Driver voltage must be ≥Vf, voltages add up for series LEDs. |
| Forward Current | If | Current value for normal LED operation. | Usually constant current drive, current determines brightness & lifespan. |
| Max Pulse Current | Ifp | Peak current tolerable for short periods, used for dimming or flashing. | Pulse width & duty cycle must be strictly controlled to avoid damage. |
| Reverse Voltage | Vr | Max reverse voltage LED can withstand, beyond may cause breakdown. | Circuit must prevent reverse connection or voltage spikes. |
| Thermal Resistance | Rth (°C/W) | Resistance to heat transfer from chip to solder, lower is better. | High thermal resistance requires stronger heat dissipation. |
| ESD Immunity | V (HBM), e.g., 1000V | Ability to withstand electrostatic discharge, higher means less vulnerable. | Anti-static measures needed in production, especially for sensitive LEDs. |
Thermal Management & Reliability
| Term | Key Metric | Simple Explanation | Impact |
|---|---|---|---|
| Junction Temperature | Tj (°C) | Actual operating temperature inside LED chip. | Every 10°C reduction may double lifespan; too high causes light decay, color shift. |
| Lumen Depreciation | L70 / L80 (hours) | Time for brightness to drop to 70% or 80% of initial. | Directly defines LED "service life". |
| Lumen Maintenance | % (e.g., 70%) | Percentage of brightness retained after time. | Indicates brightness retention over long-term use. |
| Color Shift | Δu′v′ or MacAdam ellipse | Degree of color change during use. | Affects color consistency in lighting scenes. |
| Thermal Aging | Material degradation | Deterioration due to long-term high temperature. | May cause brightness drop, color change, or open-circuit failure. |
Packaging & Materials
| Term | Common Types | Simple Explanation | Features & Applications |
|---|---|---|---|
| Package Type | EMC, PPA, Ceramic | Housing material protecting chip, providing optical/thermal interface. | EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life. |
| Chip Structure | Front, Flip Chip | Chip electrode arrangement. | Flip chip: better heat dissipation, higher efficacy, for high-power. |
| Phosphor Coating | YAG, Silicate, Nitride | Covers blue chip, converts some to yellow/red, mixes to white. | Different phosphors affect efficacy, CCT, and CRI. |
| Lens/Optics | Flat, Microlens, TIR | Optical structure on surface controlling light distribution. | Determines viewing angle and light distribution curve. |
Quality Control & Binning
| Term | Binning Content | Simple Explanation | Purpose |
|---|---|---|---|
| Luminous Flux Bin | Code e.g., 2G, 2H | Grouped by brightness, each group has min/max lumen values. | Ensures uniform brightness in same batch. |
| Voltage Bin | Code e.g., 6W, 6X | Grouped by forward voltage range. | Facilitates driver matching, improves system efficiency. |
| Color Bin | 5-step MacAdam ellipse | Grouped by color coordinates, ensuring tight range. | Guarantees color consistency, avoids uneven color within fixture. |
| CCT Bin | 2700K, 3000K etc. | Grouped by CCT, each has corresponding coordinate range. | Meets different scene CCT requirements. |
Testing & Certification
| Term | Standard/Test | Simple Explanation | Significance |
|---|---|---|---|
| LM-80 | Lumen maintenance test | Long-term lighting at constant temperature, recording brightness decay. | Used to estimate LED life (with TM-21). |
| TM-21 | Life estimation standard | Estimates life under actual conditions based on LM-80 data. | Provides scientific life prediction. |
| IESNA | Illuminating Engineering Society | Covers optical, electrical, thermal test methods. | Industry-recognized test basis. |
| RoHS / REACH | Environmental certification | Ensures no harmful substances (lead, mercury). | Market access requirement internationally. |
| ENERGY STAR / DLC | Energy efficiency certification | Energy efficiency and performance certification for lighting. | Used in government procurement, subsidy programs, enhances competitiveness. |