LED Component Datasheet - Lifecycle Phase Revision 3 - Technical Documentation

1. Document Overview

This technical document serves as a datasheet for an LED component, with a primary focus on its document lifecycle and revision control. The core information provided pertains to the formal release and versioning of the technical specifications. The document is identified as being in the "Revision" phase of its lifecycle, indicating it is an updated version of a previous document. The revision number is consistently noted as 3, signifying this is the third major iteration. The release date for this revision is standardized as October 13, 2015, at 16:57:38. A key characteristic is the "Expired Period" being set to "Forever," which implies this document version does not have a predefined expiration date and is intended to remain valid indefinitely unless superseded by a newer revision. This setup is typical for foundational technical specifications that form a permanent reference point.

2. Lifecycle and Revision Management

The document structure repeatedly emphasizes the lifecycle phase and revision details. This repetitive presentation likely serves to ensure this critical metadata is prominently visible and unambiguous, which is essential for quality control and traceability in manufacturing and engineering processes.

2.1 Lifecycle Phase: Revision

The designation "LifecyclePhase: Revision" clearly states that this document is not a draft or an obsolete version but an active, corrected, or updated set of specifications. Being in the Revision phase means it has passed through initial drafting and review stages and has been officially issued for use.

2.2 Revision Number: 3

The revision number "3" is crucial for version control. It allows engineers, procurement specialists, and production teams to precisely identify which set of specifications applies to a component. This prevents errors that could arise from using outdated parameters. Changes from Revision 2 to Revision 3 could include updates to technical tolerances, material specifications, test procedures, or recommended application notes.

2.3 Release Date and Time

The specific release timestamp "2015-10-13 16:57:38.0" provides an exact point of origin for this document version. This is vital for auditing, compliance, and in scenarios where the performance or specifications of components produced after this date must be traced back to this specific document revision.

2.4 Expired Period: Forever

The "Expired Period: Forever" attribute is significant. It indicates that this revision does not automatically become invalid after a certain date. Instead, it remains the governing specification until explicitly replaced by a newer revision (e.g., Revision 4). This is common for datasheets of mature, stable components where the core technology and design are not expected to change frequently.

3. Technical Parameters and Specifications

While the provided text snippet focuses on document metadata, a complete LED datasheet based on this revision would contain detailed technical parameters. The following sections outline the typical content expected in such a document, which would be defined by this Revision 3.

3.1 Photometric and Color Characteristics

A comprehensive datasheet would specify the photometric properties of the LED. This includes the dominant wavelength or correlated color temperature (CCT), which defines the color of light emitted (e.g., cool white, warm white, red, blue). The luminous flux, measured in lumens (lm), indicates the total perceived light output. Chromaticity coordinates (e.g., on the CIE 1931 chart) would be provided for precise color definition. The viewing angle, specifying the angular distribution of light (e.g., 120 degrees), is also a key parameter. These characteristics are fundamental for application design, ensuring the LED meets the required brightness and color quality.

3.2 Electrical and Thermal Parameters

Critical electrical specifications include the forward voltage (Vf) at a given test current, which is essential for driver circuit design. The forward current (If) rating, both continuous and peak, dictates the operating limits. Thermal resistance (from junction to ambient or solder point) is a vital parameter for managing heat dissipation, as LED performance and lifespan are highly temperature-dependent. Maximum junction temperature (Tj max) is the absolute limit that must not be exceeded.

3.3 Mechanical and Package Information

The physical dimensions of the LED package (length, width, height) would be detailed, often with a dimensioned drawing. The package type (e.g., 2835, 5050) is a standard industry identifier. Information on the solder pad layout, polarity marking (anode/cathode identification), and recommended land pattern for PCB design are included. Material specifications for the lens, substrate, and leads may also be provided.

4. Performance Analysis and Curves

Graphical data is essential for understanding component behavior under varying conditions.

4.1 Current vs. Voltage (I-V) Curve

The I-V curve illustrates the relationship between the forward voltage and the current flowing through the LED. It shows the turn-on voltage and how Vf increases with current. This curve is fundamental for designing constant-current drivers.

4.2 Temperature Dependence

Graphs typically show how luminous flux and forward voltage change with the junction temperature. Luminous output generally decreases as temperature rises, while forward voltage typically decreases. Understanding these relationships is critical for thermal management in the final application.

4.3 Spectral Power Distribution

A spectral distribution graph plots the relative intensity of light emitted at each wavelength. For white LEDs, this shows the blue pump peak and the broader phosphor emission. It is key for assessing color rendering properties.

5. Application Guidelines and Design Considerations

This section translates technical parameters into practical design rules.

5.1 Soldering and Assembly

Recommended reflow soldering profiles (preheat, soak, reflow, cooling times and temperatures) would be specified to prevent thermal damage to the LED package. Hand-soldering guidelines, if applicable, and warnings about electrostatic discharge (ESD) sensitivity are also common.

5.2 Thermal Management

Based on the thermal resistance and maximum junction temperature, guidance is provided on PCB layout for heat sinking. This may include recommendations for thermal via patterns, copper pad area, and the potential use of metal-core PCBs (MCPCBs) for high-power applications.

5.3 Electrical Drive Circuit

Design notes emphasize the importance of using a constant-current driver rather than a constant-voltage source to ensure stable light output and long life. Calculations for series/parallel configurations and considerations for dimming (PWM or analog) might be included.

6. Reliability and Quality Assurance

While not in the snippet, a full datasheet under this revision would define reliability metrics. This includes rated lifetime (often L70 or L50, indicating hours until lumen output degrades to 70% or 50% of initial), test conditions for lifetime estimation, and environmental stress tests performed (such as temperature cycling, humidity testing, and solder heat resistance).

7. Packaging and Ordering Information

The datasheet would conclude with logistics information. This covers the packaging format (e.g., tape and reel specifications, reel size, quantity per reel). The part number or ordering code structure is explained, showing how to specify different bins for color, flux, and voltage. Labels for lot traceability and date codes are also described.

8. Technical Comparison and Trends

In a broader context, the existence of a Revision 3 datasheet reflects the evolution of LED technology. Revisions often incorporate improvements in efficiency (higher lumens per watt), color consistency (tighter binning), and reliability. Compared to earlier revisions or competing products, advancements might be seen in thermal performance, allowing for higher drive currents, or in the quality of light (higher Color Rendering Index - CRI). The trend in the industry continues toward higher efficacy, better color rendering, and increased integration (e.g., Chip-on-Board - COB, or integrated driver LEDs).

9. Frequently Asked Questions (FAQ)

Q: What does "LifecyclePhase: Revision" mean for my design?
A: It means you are using the most current, officially released set of specifications. Always ensure your BOM (Bill of Materials) and production files reference this specific revision (Rev. 3) to guarantee consistency.

Q: The Expired Period is "Forever." Does this mean the component will never be updated?
A: No. "Forever" means this document version has no auto-expiry. The component or its datasheet can still be updated, resulting in a new revision (e.g., Rev. 4). You should periodically check for updates from the source.

Q: How do I use the release date information?
A: It is used for traceability. If a quality issue arises, you can confirm whether produced units were built according to the specifications valid at the time of manufacture by cross-referencing this date.

Q: What is typically updated in a datasheet revision?
A: Revisions can correct typographical errors, clarify ambiguous text, update test methods, add new application notes, or, most importantly, reflect changes in the component's guaranteed performance specifications based on improved manufacturing processes.

10. Conclusion

This datasheet, governed by the metadata of Lifecycle Phase: Revision 3, released on October 13, 2015, and with an indefinite validity period, forms a stable technical foundation for the application of the specified LED component. While the provided excerpt highlights the importance of document control, the full technical content it represents encompasses detailed photometric, electrical, thermal, and mechanical specifications. Successful implementation requires careful attention to all parameters, adherence to application guidelines—especially concerning thermal management and electrical driving—and strict referencing of this revision to ensure design integrity and product reliability. The principles of constant-current operation, effective heat sinking, and ESD protection remain universally critical for LED-based designs.