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

1. Product Overview

This technical document provides comprehensive specifications and guidelines for a specific LED component. The primary focus is on the established lifecycle phase of the product, which is currently in Revision 2. This revision indicates a mature and stable product design, having undergone necessary updates and improvements since its initial release. The product is designed for long-term availability, as indicated by its "Forever" expired period, making it suitable for projects requiring consistent supply and design stability over extended periods. The core advantage lies in its reliability and the assurance of a fixed specification set, which is critical for manufacturing consistency and product performance predictability.

The target market for this component includes general lighting applications, consumer electronics, indicator lights, and various embedded systems where a dependable, standardized light source is required. Its design prioritizes consistent performance parameters to ensure uniform light output and electrical characteristics across large production batches.

2. In-Depth Technical Parameter Analysis

While the provided PDF excerpt focuses on lifecycle metadata, a complete datasheet for an LED component would typically include the following detailed technical parameters. This analysis is based on standard industry specifications for such components.

2.1 Photometric and Color Characteristics

The photometric properties define the light output and quality. Key parameters include luminous flux, measured in lumens (lm), which indicates the total perceived power of light emitted. The correlated color temperature (CCT), measured in Kelvin (K), specifies whether the light appears warm, neutral, or cool white. For colored LEDs, the dominant wavelength is provided, measured in nanometers (nm). Color rendering index (CRI) is another critical parameter, especially for white LEDs, indicating how accurately the light source reveals the true colors of objects compared to a natural light source. Typical values for general-purpose white LEDs range from 70 to 90+ CRI. The viewing angle, specified in degrees, describes the angular distribution of the light intensity.

2.2 Electrical Parameters

Electrical specifications are fundamental for circuit design. The forward voltage (Vf) is the voltage drop across the LED when it is operating at its specified current. It is typically provided at a standard test current (e.g., 20mA, 150mA) and can have a range (e.g., 2.8V to 3.4V). The forward current (If) is the recommended operating current for achieving the rated luminous flux and longevity. Exceeding the maximum forward current can drastically reduce the LED's lifespan. The reverse voltage (Vr) is the maximum voltage the LED can withstand when connected in reverse bias without being damaged. Power dissipation is calculated as Vf * If and must be managed to prevent overheating.

2.3 Thermal Characteristics

LED performance and lifespan are highly dependent on temperature management. The junction temperature (Tj) is the temperature at the semiconductor chip itself. Maintaining Tj below its maximum rated value (often 125°C) is crucial. The thermal resistance from junction to solder point (Rth j-sp) or to ambient (Rth j-a) quantifies how effectively heat is transferred away from the chip. A lower thermal resistance value indicates better heat dissipation capability. Proper heatsinking and PCB design are essential to manage thermal performance, especially for high-power LEDs.

3. Binning System Explanation

To ensure consistency, LEDs are sorted into bins based on key parameters measured during production.

3.1 Wavelength/Color Temperature Binning

LEDs are binned according to their dominant wavelength (for monochromatic LEDs) or correlated color temperature (for white LEDs). This ensures that LEDs from the same bin will have nearly identical color appearance. Bins are defined by specific wavelength or CCT ranges (e.g., 450-455nm, 6000-6500K). Using LEDs from the same bin within a single product is critical to avoid visible color differences.

3.2 Luminous Flux Binning

Luminous flux output is also binned. LEDs are sorted into groups based on their measured light output at a standard test current. This allows designers to select components that meet specific brightness requirements and ensures uniformity in multi-LED assemblies.

3.3 Forward Voltage Binning

Forward voltage is binned to group LEDs with similar Vf characteristics. This is important for designs using multiple LEDs in series, as it helps maintain uniform current distribution and simplifies driver design by reducing the voltage range the driver must accommodate.

4. Performance Curve Analysis

Graphical data provides deeper insight into LED behavior under varying conditions.

4.1 Current-Voltage (I-V) Characteristic Curve

The I-V curve shows the relationship between the forward voltage and the current flowing through the LED. It is non-linear. Below the threshold voltage, very little current flows. Once the threshold is exceeded, current increases rapidly with a small increase in voltage. This curve is essential for designing constant-current drivers, which are preferred over constant-voltage drivers for LEDs to ensure stable light output and prevent thermal runaway.

4.2 Temperature Dependency

Graphs typically show how luminous flux and forward voltage change with junction temperature. Luminous flux generally decreases as temperature increases. Forward voltage typically decreases with increasing temperature. Understanding these relationships is vital for designing systems that maintain performance across their operating temperature range.

3.3 Spectral Power Distribution (SPD)

The SPD graph plots the relative intensity of light emitted at each wavelength. For white LEDs, it shows the broad spectrum created by the phosphor coating over a blue LED chip. This graph is key for understanding color quality, CRI, and the specific spectral peaks of the LED.

5. Mechanical and Package Information

The physical package ensures reliable mounting and electrical connection.

5.1 Dimensional Outline Drawing

A detailed drawing provides all critical dimensions: length, width, height, lens shape, and lead spacing. Tolerances are specified for each dimension. This drawing is necessary for creating accurate PCB footprints and ensuring proper fit within the final assembly.

5.2 Pad Layout Design

The recommended PCB land pattern (footprint) is provided, including pad size, shape, and spacing. Following this recommendation ensures good solder joint formation during reflow and provides adequate mechanical strength and thermal conduction.

5.3 Polarity Identification

Clear markings indicate the anode and cathode. Common indicators include a notch on the package, a green dot on the cathode side, or different lead lengths. Correct polarity is essential for the LED to function.

6. Soldering and Assembly Guidelines

Proper handling and soldering are critical to reliability.

6.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow, and cooling stages. Key parameters are peak temperature (typically not exceeding 260°C for a few seconds), time above liquidus (TAL), and ramp rates. Adhering to this profile prevents thermal shock and damage to the LED package and internal die.

6.2 Precautions and Handling

LEDs are sensitive to electrostatic discharge (ESD). Handling should be done at ESD-protected workstations using grounded tools. Avoid mechanical stress on the lens. Do not clean with solvents that may damage the silicone lens or epoxy package.

6.3 Storage Conditions

LEDs should be stored in a dry, dark environment at controlled temperature and humidity, typically as per the Moisture Sensitivity Level (MSL) rating on the packaging. This prevents moisture absorption which can cause "popcorning" (package cracking) during reflow soldering.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The component is supplied on tape and reel for automated assembly. The reel dimensions, tape width, pocket size, and component orientation on the tape are specified. The quantity per reel is also provided (e.g., 2000 pieces per reel).

7.2 Labeling and Part Numbering

The part number is structured to encode key attributes. A typical structure might include: Series Code, Color/Color Temperature, Flux Bin, Voltage Bin, and Package Code. Understanding this structure allows for precise ordering of the required specification.

8. Application Recommendations

8.1 Typical Application Circuits

Basic application circuits include a series resistor for current limiting when using a constant voltage source. For optimal performance, especially with multiple LEDs or high-power LEDs, a dedicated constant-current LED driver IC is recommended. Circuit diagrams for both configurations are often included.

8.2 Design Considerations

Key design considerations include thermal management (PCB copper area, thermal vias, possible heatsink), optical design (lens selection, diffusers), and electrical design (driver selection, dimming method, protection against reverse polarity and overvoltage). Ensuring the LED operates within its Absolute Maximum Ratings is paramount for reliability.

9. Technical Comparison and Differentiation

Compared to earlier revisions or alternative products, Revision 2 of this LED component may offer improvements in several areas. These could include higher luminous efficacy (more lumens per watt), improved color consistency through tighter binning, enhanced reliability data from extended lifetime testing, or a more robust package design. The "Forever" lifecycle status differentiates it from end-of-life (EOL) or new, unproven products by offering long-term supply stability, which is a critical factor for industrial and automotive applications.

10. Frequently Asked Questions (FAQ)

Q: What does "LifecyclePhase: Revision 2" mean?
A: It indicates this is the second major revision of the product datasheet/specification. The product design is stable and mature, with updates likely focused on refined specifications, improved test data, or clarified guidelines based on field experience.

Q: What is the implication of "Expired Period: Forever"?
A: This suggests the manufacturer intends to produce and support this specific component variant indefinitely, or for the foreseeable future. It is not scheduled for obsolescence, providing supply security for long-term projects.

Q: How should I interpret the release date?
A: The release date (2014-12-05) is when this specific revision (Rev. 2) of the document was issued. Always refer to the latest revision for the most current specifications.

Q: Can I mix LEDs from different bins in my design?
A: It is strongly discouraged, especially for color and flux bins. Mixing bins can lead to visible color and brightness variations in the final product. Always specify and use LEDs from a single bin for consistent results.

11. Practical Application Case Study

Consider a task lighting fixture designed for office environments. The design requires uniform, high-CRI white light. Using this LED in Revision 2, the design team would:
1. Select a specific CCT bin (e.g., 4000K) and high CRI bin (e.g., >80) from the ordering code.
2. Design a PCB with adequate thermal pads and copper pours to keep the junction temperature below 105°C in the fixture's enclosed environment.
3. Use a constant-current driver module rated for the total forward voltage of the LED array at the desired current.
4. Implement optical elements (reflectors or diffusers) based on the LED's viewing angle to achieve the desired beam pattern and eliminate glare.
The "Forever" lifecycle assurance allows the manufacturer to plan for multi-year production runs of the lighting fixture without concern for component obsolescence.

12. Operating Principle Introduction

An LED is a semiconductor diode. When a forward voltage is applied, electrons from the n-type semiconductor recombine with holes from the p-type semiconductor in the active region, releasing energy in the form of photons (light). The wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor materials used (e.g., InGaN for blue/green, AlInGaP for red/amber). White LEDs are typically created by coating a blue LED chip with a phosphor material that absorbs some of the blue light and re-emits it as a broader spectrum of yellow light; the mix of blue and yellow light is perceived as white.

13. Technology Trends and Developments

The solid-state lighting industry continues to evolve. General trends include increasing luminous efficacy, reducing cost per lumen, and improving color quality and consistency. Miniaturization of packages continues, enabling higher density displays and lighting. There is also a strong trend towards intelligent, connected lighting with integrated sensors and controls. Furthermore, research into novel materials like perovskites and quantum dots aims to create LEDs with superior color purity and efficiency. The long-term availability of mature products like this Revision 2 component coexists with the rapid development of next-generation technologies, serving different segments of the market based on requirements for performance, cost, and supply stability.