LED Component Lifecycle Document - Revision 2 - Release Date 2014-12-02 - English Technical Specification

1. Product Overview

This technical document provides comprehensive information regarding the lifecycle management of a specific electronic component, identified as being in the "Revision" phase. The primary focus is on the formalization of Revision 2, which was officially released on December 2nd, 2014, at 15:01:29. The document establishes the component's status and its associated parameters for engineering and procurement purposes. The core advantage of this documentation is its clarity in defining the component's revision state and its indefinite validity, providing stability for long-term product designs and supply chain planning. It is targeted at engineers, procurement specialists, and quality assurance personnel involved in the selection and integration of this component into larger electronic assemblies.

2. Lifecycle and Revision Information

The document repeatedly and consistently specifies a single, critical set of metadata for the component.

2.1 Lifecycle Phase

The component is explicitly stated to be in the "Revision" phase. This indicates that the component design is not in its initial release (Prototype or Initial Production) nor is it obsolete. It is a stable, revised version of the product, implying that previous iterations existed and that this version incorporates updates, improvements, or corrections. Being in the Revision phase suggests maturity and reliability for volume production.

2.2 Revision Number

The revision number is clearly defined as 2. This numerical designation is crucial for version control, ensuring that all parties involved in the design, manufacturing, and testing processes are referencing the exact same specification. It allows for traceability and helps prevent errors that could arise from using outdated or incorrect documentation.

2.3 Release Date and Time

The official release timestamp for Revision 2 is 2014-12-02 15:01:29.0. This precise timestamp serves as an official milestone, marking when this specific revision of the documentation became active and authoritative. It is essential for historical tracking and for understanding the timeline of the product's development.

2.4 Expiration Period

The document states the expiration period as "Forever". This is a significant declaration meaning that this revision of the document does not have a planned obsolescence date within the document's own terms. The specifications contained within are intended to remain valid indefinitely, or until superseded by a new revision. This provides long-term certainty for design and manufacturing commitments.

3. Technical Parameters and Specifications

While the provided PDF snippet focuses on administrative metadata, a complete technical document for an electronic component would contain several detailed sections. Based on the context of a lifecycle document for a likely LED or similar component, the following sections would be critically analyzed.

3.1 Photometric and Color Characteristics

A detailed technical datasheet would include precise measurements of the component's light output. This involves Luminous Flux (measured in lumens), which indicates the total perceived power of light emitted. Color Temperature (measured in Kelvin, K) defines whether the light appears warm (e.g., 2700K), neutral (e.g., 4000K), or cool (e.g., 6500K). Color Rendering Index (CRI) is a measure of how accurately the light source reveals the true colors of objects compared to a natural light source, with higher values (closer to 100) being better. Chromaticity Coordinates (x, y on the CIE 1931 diagram) provide the exact color point of the emitted light. For colored LEDs, the Dominant Wavelength and Peak Wavelength would be specified.

3.2 Electrical Parameters

Key electrical specifications are fundamental for circuit design. The Forward Voltage (Vf) is the voltage drop across the LED when it is operating at a specified current. This parameter has a typical value and a range (e.g., 3.0V to 3.4V at 20mA). The Forward Current (If) is the recommended operating current, often given as a continuous DC value and an absolute maximum rating. Reverse Voltage (Vr) specifies the maximum voltage that can be applied in the reverse direction without damaging the device. Power Dissipation is calculated from Vf and If and is crucial for thermal management.

3.3 Thermal Characteristics

LED performance and lifespan are heavily dependent on temperature. The Junction Temperature (Tj) is the temperature at the semiconductor chip itself, and its maximum allowable value is a critical limit. The Thermal Resistance (Rth_j-a), measured in °C/W, indicates how effectively heat travels from the junction to the ambient air. A lower value means better heat dissipation. Understanding these parameters is essential for designing an adequate heatsink or thermal management system to ensure longevity and maintain light output.

4. Binning and Classification System

Manufacturing variations mean LEDs are sorted into bins to ensure consistency.

4.1 Wavelength and Color Temperature Binning

LEDs are binned based on their chromaticity coordinates to ensure a uniform appearance in an array. A datasheet will define the specific bins (e.g., 3-step, 5-step MacAdam ellipses) that guarantee all LEDs from the same bin will appear visually identical. For white LEDs, this is often expressed as bins within a certain range of the Duv (distance from the black body locus) and correlated color temperature (CCT).

4.2 Luminous Flux Binning

LEDs are also sorted by their light output. A flux binning system groups LEDs according to their measured luminous flux at a standard test current. This allows designers to select components that meet specific brightness requirements and ensures predictable performance in the final application.

4.3 Forward Voltage Binning

To aid in designing efficient driver circuits and ensuring consistent current distribution in parallel strings, LEDs may be binned by their forward voltage (Vf). This groups devices with similar Vf characteristics together.

5. Performance Curve Analysis

Graphical data provides deeper insight than tabular data alone.

5.1 Current vs. Voltage (I-V) Curve

The I-V curve shows the relationship between the current flowing through the LED and the voltage across it. It is non-linear, exhibiting a turn-on voltage below which very little current flows. The slope of the curve in the operating region relates to the dynamic resistance of the LED. This curve is essential for selecting an appropriate current-limiting driver.

5.2 Temperature Characteristics

Graphs typically show how key parameters degrade with increasing temperature. This includes the relative luminous flux vs. junction temperature, where output decreases as temperature rises. The forward voltage vs. temperature curve is also important, as Vf has a negative temperature coefficient (it decreases as temperature increases), which can affect constant-current drive stability.

5.3 Spectral Power Distribution

This graph plots the relative intensity of light emitted at each wavelength. For white LEDs (often blue chip + phosphor), it shows the blue peak from the chip and the broader yellow/red emission from the phosphor. The shape of this curve directly determines the color temperature and CRI of the LED.

6. Mechanical and Package Information

Physical dimensions and construction details are vital for PCB design and assembly.

6.1 Outline Dimensions and Tolerances

A detailed dimensional drawing provides all critical measurements: length, width, height, lead spacing, and any tolerances. This ensures the component will fit the designated footprint on the printed circuit board (PCB).

6.2 Pad Layout and Solder Pad Design

The recommended PCB land pattern (solder pad geometry) is provided to ensure a reliable solder joint during reflow or wave soldering. This includes pad size, shape, and spacing relative to the component terminals.

6.3 Polarity Identification

The method for identifying the anode and cathode is clearly indicated, usually through a marking on the component body (e.g., a notch, a dot, a green line, or a longer lead). Correct polarity is essential for proper operation.

7. Soldering and Assembly Guidelines

Proper handling ensures reliability.

7.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow peak temperature, and cooling rates. Maximum temperature and time-at-temperature limits are specified to prevent thermal damage to the LED package and internal die.

7.2 Handling and Storage Precautions

Instructions typically include protection from electrostatic discharge (ESD), as LEDs are sensitive semiconductor devices. Recommendations for storage conditions (temperature and humidity) are given to prevent moisture absorption, which can cause "popcorning" during reflow.

8. Packaging and Ordering Information

Logistics for procurement and production.

8.1 Packaging Specifications

Details on how the components are supplied: reel type (e.g., 7-inch or 13-inch), tape width, pocket spacing, and orientation. Quantity per reel is also specified.

8.2 Labeling and Part Numbering

Explanation of the part number code, which typically encodes key attributes like color, flux bin, voltage bin, and package type. This allows precise ordering of the required specification.

9. Application Notes and Design Considerations

Guidance for successful implementation.

9.1 Typical Application Circuits

Schematics for basic drive circuits, such as series resistor calculation for low-current applications or constant-current driver IC recommendations for higher-power or precision applications.

9.2 Thermal Management Design

Critical guidance on designing the PCB and system to manage heat. This includes recommendations for thermal vias, copper pour area, and the potential need for an external heatsink to keep the junction temperature within safe limits for long-term reliability.

9.3 Optical Design Considerations

Notes on the viewing angle, beam pattern, and the potential need for secondary optics (lenses, diffusers) to achieve the desired illumination profile in the final application.

10. Technical Comparison and Differentiation

While this specific document is administrative, a full datasheet might highlight advantages over previous revisions or competing products. For Revision 2, improvements could include higher luminous efficacy (more lumens per watt), improved color consistency (tighter binning), enhanced reliability data (longer L70 lifetime), or a more robust package design. These differentiators would be key for engineers evaluating the component.

11. Frequently Asked Questions (FAQ)

Based on common technical queries:

Q: What does "Lifecycle Phase: Revision" mean for sourcing?
A: It indicates the component is in active, stable production. It is not a new prototype (which may have supply issues) nor is it obsolete (which would trigger a last-time-buy notice). Long-term supply is expected.

Q: The expiration is "Forever." Does this mean the component will never be obsolete?
A: No. "Forever" in this context means the document for Revision 2 does not expire. The component itself may eventually reach an "Obsolete" lifecycle phase in the future, which would be communicated via a separate Product Change Notice (PCN) or discontinuance notice.

Q: How do I ensure I am using the correct revision in my design?
A: Always reference the specific revision number (in this case, 2) and release date in your Bill of Materials (BOM) and design files. Verify the marking on received components if possible.

12. Practical Use Case Examples

Case Study 1: Architectural Lighting Fixture
A designer selects this component, noting its Revision 2 status for supply stability. They use the flux and color bins to ensure uniform white light across a large linear fixture. The thermal resistance data is used to calculate the required aluminum heatsink size to maintain junction temperature below 85°C, ensuring the advertised 50,000-hour lifetime.

Case Study 2: Consumer Electronics Indicator
An engineer designs a status indicator for a home appliance. The low power consumption and stable forward voltage parameters from the datasheet allow for a simple series resistor drive circuit. The precise mechanical dimensions ensure the LED fits perfectly into the molded lens of the product housing.

13. Operational Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons recombine with holes within the device, releasing energy in the form of photons. The color of the emitted light is determined by the energy band gap of the semiconductor material used (e.g., Gallium Nitride for blue/UV, Aluminum Gallium Indium Phosphide for red/yellow/green). White LEDs are typically created by coating a blue or ultraviolet LED chip with a phosphor material that down-converts some of the light to longer wavelengths, producing a broad spectrum perceived as white.

14. Industry Trends and Developments

The LED industry continues to evolve rapidly. Key trends include:
Increased Efficacy: Ongoing improvements in chip design, phosphor technology, and package efficiency are pushing luminous efficacy higher, reducing energy consumption for the same light output.
Improved Color Quality: There is a strong focus on achieving high CRI values (90+ and even 95+) and tunable white light (adjustable CCT) for applications demanding superior color rendering, such as retail and museum lighting.
Miniaturization and Integration: The development of Chip-Scale Package (CSP) LEDs and Micro-LEDs enables smaller, denser arrays for applications like fine-pitch displays and compact lighting modules.
Smart and Connected Lighting: Integration of control electronics and communication protocols (like DALI, Zigbee) directly into LED modules is becoming more common, facilitating the growth of the Internet of Things (IoT) in lighting systems.
Reliability and Lifetime: Research continues to extend operational lifetime and understand failure mechanisms, especially under high-temperature and high-current stress conditions common in high-power applications.