LED Component Lifecycle Document - Revision 2 - Release Date 2014-12-05 - English Technical Specification

1. Product Overview

This document provides the official lifecycle and revision management information for a specific electronic component, identified here as an LED for contextual purposes. The core focus is on the formal status and version control of the product's technical specifications. The document establishes that the component is in a stable "Revision" phase, indicating that its core design and parameters are finalized and subject to controlled changes. The primary advantage conveyed is the assurance of a fixed, well-defined specification set for engineering and procurement purposes, targeting markets requiring stable, long-term component supply for product design and manufacturing.

2. Lifecycle and Revision Management

The provided content exclusively details the administrative and procedural status of the component's documentation.

2.1 Lifecycle Phase

The LifecyclePhase is explicitly stated as Revision. This denotes a specific stage in the product's documentation and release cycle. A "Revision" phase typically follows initial release and indicates that the product is actively maintained. Updates are made through formal revision processes, resulting in new version numbers (e.g., Revision 2). This phase assures users that the product is not in a prototype, pre-release, or end-of-life state, but is a mature and supported component.

2.2 Revision Number

The document specifies Revision: 2. This is a critical identifier for version control. Engineers and procurement specialists must reference this exact revision number to ensure they are using the correct set of specifications. Any change in electrical, optical, or mechanical parameters would be reflected in an increment of this revision number, necessitating a review of the complete updated datasheet.

2.3 Release and Validity Information

The Release Date is recorded as 2014-12-05 12:05:40.0. This timestamp marks the official publication of Revision 2 of this document. The Expired Period is listed as Forever. This is an unusual but significant designation in technical documentation. It implies that this specific revision of the document does not have a planned obsolescence date and remains valid indefinitely as a reference for the specified product revision. However, it does not mean the product itself is in production forever; a separate "End-of-Life" notice would typically govern the product's manufacturability.

3. Technical Parameters and Specifications

While the provided text snippet does not contain explicit technical parameters, a component in "Revision 2" status would have a fully defined set of specifications. Based on standard LED component documentation, the following sections detail the typical parameters that would be contained in the full datasheet referenced by this lifecycle document.

3.1 Photometric and Color Characteristics

The full specification would define key optical properties. Dominant Wavelength or Correlated Color Temperature (CCT) would be specified, typically with binning codes to manage manufacturing variance (e.g., 6000K-6500K for cool white). Luminous Flux (in lumens) at a given test current would be a primary performance metric, also often binned. Color Rendering Index (CRI) might be specified for white LEDs. Chromaticity coordinates (e.g., CIE x, y) would be provided within defined tolerances on a chromaticity diagram.

3.2 Electrical Characteristics

Absolute maximum ratings and typical operating conditions would be specified. The Forward Voltage (Vf) at a specific test current (e.g., 60mA) is a critical parameter for circuit design, often provided as a typical value and a maximum. A Reverse Voltage (Vr) rating would be given. The Continuous Forward Current (If) rating defines the maximum safe operating current. Pulse Current ratings might also be included.

3.3 Thermal Characteristics

Thermal management is crucial for LED performance and longevity. The Thermal Resistance, Junction to Ambient (RθJA) would be specified, indicating how effectively heat is dissipated from the semiconductor junction to the environment. The Maximum Junction Temperature (Tj) is the highest allowable temperature at the LED chip itself. These parameters directly inform heatsink design and system thermal management.

3.4 Binning System Explanation

To ensure consistency, manufacturers implement binning. Wavelength/CCT Binning groups LEDs based on their precise color output. Luminous Flux Binning groups them based on light output efficiency. Forward Voltage Binning groups them based on electrical characteristics. The full datasheet would include detailed binning code tables, allowing designers to select the precise performance grade required for their application, balancing cost and performance.

4. Performance Curve Analysis

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 non-linear relationship between forward current and forward voltage. It shows the turn-on voltage and how Vf increases with current. This curve is fundamental for designing the driver circuit, whether it's a constant current or constant voltage type.

4.2 Relative Luminous Flux vs. Forward Current

This graph shows how light output scales with input current. It is typically non-linear, with efficiency (lumens per watt) often peaking at a current lower than the absolute maximum rating. Operating above this peak efficiency point increases output but reduces efficacy and generates more heat.

4.3 Relative Luminous Flux vs. Junction Temperature

This critical graph demonstrates the thermal dependency of light output. As the LED junction temperature (Tj) increases, luminous flux generally decreases. The curve allows designers to predict the light output loss at their system's operating temperature, which is vital for ensuring the application meets its brightness requirements over its lifetime.

4.4 Spectral Power Distribution

For colored or white LEDs, an SPD graph plots the intensity of light emitted at each wavelength. It provides a visual representation of color purity for monochromatic LEDs or the phosphor-converted spectrum for white LEDs, informing applications sensitive to specific spectral content.

5. Mechanical and Packaging Information

Precise physical specifications are necessary for PCB design and assembly.

5.1 Dimensional Outline Drawing

A detailed mechanical drawing would show the component's exact dimensions: length, width, height, and any curvature or chamfer. Critical tolerances would be indicated. This drawing ensures the component fits the intended footprint on the PCB and within the final product assembly.

5.2 Pad Layout and Footprint Design

The recommended PCB land pattern (footprint) would be provided, including pad size, shape, and spacing. Adhering to this design is crucial for reliable soldering, proper thermal dissipation through the pads, and preventing tombstoning or other assembly defects.

5.3 Polarity Identification

A clear method for identifying the anode and cathode would be specified. This is often a visual marker on the LED package itself, such as a notch, a cut corner, a green dot, or a longer lead (in through-hole types). The datasheet would explicitly illustrate this marking.

6. Soldering and Assembly Guidelines

Proper handling ensures reliability and prevents damage during manufacturing.

6.1 Reflow Soldering Profile

A detailed temperature vs. time graph would define the acceptable reflow profile. Key parameters include: preheat ramp rate, soak temperature and time, peak temperature (which must not exceed the component's maximum soldering temperature), and cooling rate. Following this profile prevents thermal shock and solder joint defects.

6.2 Handling and Storage Precautions

Instructions would include protection from electrostatic discharge (ESD), which can damage the LED chip. Recommendations for storage conditions (temperature and humidity) to prevent moisture absorption (which can cause "popcorning" during reflow) would be provided, along with shelf life information for moisture-sensitive devices.

7. Application Notes and Design Considerations

7.1 Typical Application Circuits

Basic circuit diagrams would be shown, such as a simple series resistor circuit for low-current applications or a constant-current driver circuit for optimal performance and stability. Design equations for calculating the current-limiting resistor would be provided.

7.2 Thermal Management Design

Detailed guidance on heatsinking would be emphasized. This includes calculating the required heatsink thermal resistance based on the LED's RθJA, input power, ambient temperature, and desired junction temperature. Proper PCB layout with thermal vias and copper pours to act as a heatsink would be discussed.

7.3 Optical Design Considerations

Notes might include viewing angle characteristics and recommendations for secondary optics (lenses, diffusers) to shape the light output for the intended application. The importance of considering the LED's spatial radiation pattern in the overall optical system would be highlighted.

8. Frequently Asked Questions (FAQ)

Q: What does "LifecyclePhase: Revision" mean for my design?

A: It means the component's specifications are stable and controlled. You can design this part into your product with confidence that its key parameters are fixed for this revision. Any future changes would result in a new revision number, giving you clear notice to re-evaluate.

Q: The Expired Period is "Forever." Does this mean the product will be available forever?

A: No. "Forever" applies to the validity of this Revision 2 document as a reference. The product's manufacturing availability is governed by separate production and End-of-Life (EOL) notices from the manufacturer. Always check for active product status notifications.

Q: How do I ensure I am using the correct revision?

A: Always download the datasheet directly from a reliable source and verify the revision number on each page. The revision noted in your Bill of Materials (BOM) should match the document revision number. The release date (2014-12-05) is a secondary identifier.

Q: Why is the forward voltage (Vf) given as a range or with binned codes?

A: Due to minor variations in semiconductor manufacturing, Vf is not a single value but falls within a statistical distribution. Binning sorts LEDs into groups with similar Vf, allowing for more predictable circuit behavior and enabling designers to select bins for tighter performance or lower cost.

Q: Can I operate the LED at its absolute maximum forward current continuously?

A: It is not recommended for optimal lifetime and efficiency. Operating at or near the absolute maximum rating increases junction temperature, accelerates lumen depreciation, and can shorten lifespan. Design for a lower typical operating current, referencing the performance curves for optimal efficacy.

9. Technical Comparison and Trends

9.1 Comparison with Preceding Technologies

While this document does not specify the exact LED type, a component in revision in 2014 would likely represent a mature mid-power LED (e.g., in a 2835 or 5630 package). Compared to earlier low-power LEDs, these offer significantly higher luminous efficacy (lumens per watt), better thermal performance due to improved package design, and higher maximum drive currents, enabling brighter outputs from a smaller footprint.

9.2 Industry Trends at Time of Release

Around the 2014-2015 timeframe, the LED industry was focused on several key trends: driving efficacy ever higher to reduce energy consumption, improving color quality (higher CRI and more consistent CCT bins), and reducing cost per lumen. Packaging technology was evolving to allow for higher power density and better light extraction. The move from traditional blue chip + yellow phosphor to multi-phosphor or violet chip + RGB phosphor mixes for better color rendering was gaining momentum.

9.3 Principle of Operation

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, releasing energy in the form of photons. The wavelength (color) of the light is determined by the energy bandgap of the semiconductor material used (e.g., InGaN for blue/green, AlInGaP for red/amber). White LEDs are typically created by coating a blue LED chip with a yellow phosphor, which converts some blue light to yellow; the mixture of blue and yellow light is perceived as white.