LED Component Datasheet - Revision 2 - Lifecycle Information - English Technical Document

1. Product Overview

This technical datasheet provides comprehensive information for an LED component, focusing on its lifecycle management and revision history. The document is structured to offer engineers and procurement specialists clear, actionable data for integration and qualification purposes. The core information centers on the formal release and revision status of the component, indicating a stable, mature product with a defined specification.

The primary advantage of this component lies in its documented and controlled lifecycle. The "Revision: 2" status signifies that the initial design has been reviewed and potentially optimized, offering improved reliability or performance consistency over the initial release. The "Expired Period: Forever" designation is a critical piece of information, indicating that this specific revision has no planned obsolescence date and is intended for long-term availability, which is essential for products requiring stable supply chains and long service lives.

The target market for such a well-documented component includes industrial lighting, automotive applications, consumer electronics, and signage where consistent performance, reliability, and long-term sourcing are paramount. The formal release date provides a clear reference point for tracking product changes and for quality assurance processes.

2. In-Depth Technical Parameter Analysis

While the provided PDF snippet focuses on lifecycle metadata, a complete datasheet for an LED component would contain detailed technical parameters. The following sections represent the typical, critical data required for design-in.

2.1 Photometric and Color Characteristics

The photometric performance defines the light output and quality. Key parameters include:

• Luminous Flux: Measured in lumens (lm), this indicates the total perceived power of light emitted. Typical values range from millilumens for indicator LEDs to hundreds of lumens for high-power lighting LEDs. The datasheet should specify minimum, typical, and maximum values at a defined test current and temperature.
• Dominant Wavelength / Correlated Color Temperature (CCT): For colored LEDs, the dominant wavelength (in nanometers) defines the perceived color (e.g., 630nm for red). For white LEDs, the CCT (in Kelvin, e.g., 3000K, 4000K, 6500K) defines whether the light appears warm, neutral, or cool white.
• Color Rendering Index (CRI): For white LEDs, CRI (Ra) measures the ability to reveal the colors of objects faithfully compared to an ideal light source. A CRI above 80 is good for general lighting, while values above 90 are required for high-fidelity applications.
• Viewing Angle: The angle at which the luminous intensity is half of the maximum intensity (often reported as 2θ½). Common angles are 120° or 180° for wide dispersion, or narrower angles like 30° for focused beams.

2.2 Electrical Parameters

Electrical specifications are crucial for circuit design and thermal management.

• Forward Voltage (Vf): The voltage drop across the LED when operating at its specified forward current. It varies with the semiconductor material (e.g., ~2.0V for red, ~3.2V for blue/white) and typically has a tolerance range (e.g., 3.0V to 3.4V). Operating above the maximum Vf can damage the LED.
• Forward Current (If): The recommended continuous DC operating current. LEDs are current-driven devices. Exceeding the absolute maximum rating leads to accelerated lumen depreciation and catastrophic failure.
• Reverse Voltage (Vr): The maximum voltage the LED can withstand when connected in reverse bias. This value is usually low (e.g., 5V) as LEDs are not designed to block reverse voltage. Protection circuits (like a diode in parallel) are often needed in AC or reverse-polarity scenarios.
• Power Dissipation: Calculated as Vf * If, this determines the heat generated within the LED chip, driving thermal design requirements.

2.3 Thermal Characteristics

LED performance and lifetime are profoundly affected by temperature.

• Junction Temperature (Tj): The temperature at the semiconductor chip itself. It is the most critical temperature for reliability. The datasheet specifies a maximum allowable Tj (e.g., 125°C or 150°C).
• Thermal Resistance (Rth j-s or Rth j-c): This parameter, measured in °C/W, indicates how effectively heat flows from the LED junction to a reference point (usually the solder point or case). A lower value means better heat dissipation. It is essential for calculating the necessary heatsinking.
• Storage Temperature Range: The temperature limits for storing the LED without applying power.

3. Binning System Explanation

Due to manufacturing variations, LEDs are sorted into performance bins to ensure consistency within a production lot.

• Wavelength / CCT Binning: LEDs are grouped by their dominant wavelength or CCT into tight ranges (e.g., 2.5nm or 100K steps). This ensures color uniformity in an array.
• Luminous Flux Binning: LEDs are sorted by their light output at a standard test condition. A common system uses codes (e.g., P1, P2, P3) where each step represents a ~5-10% difference in flux.
• Forward Voltage Binning: Sorting by Vf helps in designing efficient driver circuits, especially for series-connected strings, to ensure current matching.

The datasheet should clearly define the bin codes and their corresponding parameter ranges.

4. Performance Curve Analysis

Graphical data provides deeper insight than single-point specifications.

• I-V (Current-Voltage) Curve: Shows the relationship between forward current and forward voltage. It is non-linear, exhibiting a knee voltage. This curve is vital for selecting current-limiting resistors or designing constant-current drivers.
• Relative Luminous Flux vs. Junction Temperature: This graph typically shows that light output decreases as junction temperature increases. The slope indicates thermal sensitivity.
• Relative Luminous Flux vs. Forward Current: Shows how light output increases with current, but often with diminishing returns and increased heat at higher currents.
• Spectral Power Distribution (SPD): A graph plotting radiant power versus wavelength. For white LEDs, it shows the blue pump peak and the broader phosphor emission. This is key for understanding color quality and CRI.
• Angular Intensity Distribution: A polar plot showing how light intensity varies with viewing angle, defining the beam pattern.

5. Mechanical and Package Information

Precise physical dimensions are required for PCB layout and assembly.

• Package Dimensions: Detailed mechanical drawing with all critical dimensions (length, width, height, lens shape) and tolerances. Common packages include 2835, 3535, 5050, etc., where the numbers often represent length and width in tenths of a millimeter (e.g., 2.8mm x 3.5mm).
• Pad Layout (Footprint): Recommended PCB land pattern, including pad size, shape, and spacing. Following this ensures proper soldering and thermal conduction.
• Polarity Identification: Clear marking on the LED package (e.g., a notch, a cut corner, a green dot, or a longer anode lead) to indicate the anode (+) and cathode (-). Incorrect polarity will prevent the LED from illuminating.

6. Soldering and Assembly Guidelines

Proper handling ensures reliability and prevents damage.

• Reflow Soldering Profile: A time-temperature graph specifying the recommended preheat, soak, reflow peak temperature, and cooling rates. Peak temperature must not exceed the LED's maximum soldering temperature (often around 260°C for 10 seconds).
• Hand Soldering Instructions: If allowed, guidelines for iron temperature, tip size, and maximum soldering time per lead.
• ESD (Electrostatic Discharge) Sensitivity: Most LEDs are sensitive to ESD. Handling should follow standard ESD precautions: use grounded workstations, wrist straps, and conductive containers.
• Cleaning: Recommendations for post-solder cleaning agents, if any, that are compatible with the LED lens material.
• Storage Conditions: Typically, LEDs should be stored in a dry, dark environment at room temperature. Some may require moisture-sensitive device (MSD) handling per IPC/JEDEC standards, with baking instructions if the humidity exposure limit is exceeded.

7. Packaging and Ordering Information

Information for logistics and procurement.

• Packaging Format: Description of how LEDs are supplied (e.g., on tape-and-reel, in tubes, or in trays). Includes reel dimensions, pocket pitch, and orientation.
• Quantity per Package: Standard quantities per reel (e.g., 2000 pcs), tube, or tray.
• Labeling and Traceability: Explanation of information on the packaging label, which may include part number, bin code, lot number, date code, and quantity.
• Part Numbering System: Decoding of the product model number, which typically encodes key attributes like package size, color, flux bin, voltage bin, and CCT (for white LEDs).

8. Application Recommendations

Guidance for successful implementation.

• Typical Application Circuits: Schematic examples, such as a simple series resistor circuit for low-power indicators or a constant-current driver circuit for lighting applications.
• Thermal Management Design: Critical advice on PCB design for heat dissipation: using thermal vias, adequate copper area, and possibly an external heatsink. The goal is to keep the junction temperature well below its maximum rating to ensure long life.
• Optical Design Considerations: Notes on secondary optics (lenses, diffusers) and the impact of the LED's native viewing angle.
• Current Driving: Emphasis on using a constant-current source rather than a constant-voltage source for optimal performance and longevity. Discussion of dimming methods (PWM vs. analog).

9. Technical Comparison and Differentiation

While a single datasheet may not compare directly, its specifications imply competitive positioning.

• Efficiency (lm/W): A higher lumen-per-watt ratio indicates better energy efficiency, a key market differentiator.
• Color Consistency (MacAdam Ellipses): Tighter binning (e.g., 2-step or 3-step MacAdam ellipses) ensures minimal visible color difference between LEDs, which is premium feature.
• Lifetime (L70/B50): The number of hours until lumen output depreciates to 70% of initial (L70) for a given percentage of samples (e.g., B50 = 50% of samples). A longer rated lifetime (e.g., 50,000 hours) indicates higher reliability.
• Robustness: Higher maximum junction temperature, better moisture resistance level, or superior ESD tolerance can be advantages in harsh environments.

10. Frequently Asked Questions (FAQs)

Answers to common design questions based on technical parameters.

• Q: Can I drive this LED directly from a 5V supply? A: Not directly. You must use a current-limiting resistor or a constant-current driver. The resistor value is calculated as R = (Supply Voltage - LED Vf) / Desired If. Ensure the resistor's power rating is sufficient.
• Q: Why does the LED's brightness decrease over time in my application? A: The most common cause is excessive junction temperature due to inadequate heat sinking. Review your thermal design to ensure Tj is within limits. Lumen depreciation is accelerated by high temperature.
• Q: Can I connect multiple LEDs in series? A: Yes, but the driver must provide a voltage higher than the sum of the individual Vf values at the operating current. Also, ensure all LEDs in the string are from the same Vf bin for current balance, or use a driver that compensates for variations.
• Q: What is the difference between luminous flux (lumens) and luminous intensity (candelas)? A: Luminous flux is the total light output in all directions. Luminous intensity is the light output in a specific direction. An LED with a narrow viewing angle can have high intensity (cd) but moderate total flux (lm).

11. Practical Application Case Studies

Hypothetical examples based on typical uses.

• Case Study 1: Linear LED Strip for Architectural Accent Lighting

  Design Goal: Create a 24V, 5-meter long strip with 60 LEDs per meter, providing uniform, warm white (3000K) illumination.
  Implementation: LEDs with a Vf of 3.0V are selected. They are arranged in series-parallel groups: 8 LEDs in series (8 * 3.0V = 24V) per segment. These segments are then connected in parallel along the strip. A constant-voltage 24V driver with adequate current capacity powers the strip. A diffuser cover is used to blend individual LED points into a continuous line of light. Thermal management is achieved via a metal-core PCB (MCPCB) to dissipate heat along the entire length.

• Case Study 2: High-Reliability Exit Sign

  Design Goal: A red exit sign requiring 10+ years of continuous operation with minimal maintenance.
  Implementation: High-efficiency red LEDs with a very long L90 lifetime rating are chosen. They are driven at only 70% of their maximum rated current to drastically reduce thermal stress and extend operational life. The driver is a highly efficient, isolated constant-current module with surge protection. The design includes ample heatsinking and conformal coating on the PCB for environmental protection.

12. Operating Principle Introduction

An LED is a semiconductor diode. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material in the active region. This recombination releases energy in the form of photons (light) through a process called electroluminescence. The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material used (e.g., Aluminum Gallium Indium Phosphide for red/orange/yellow, Indium Gallium Nitride for blue/green/white). White LEDs are typically created by coating a blue LED chip with a yellow phosphor; the mixture of blue and yellow light produces white light. The color temperature and CRI are adjusted by modifying the phosphor composition.

13. Technology Trends and Developments

The LED industry continues to evolve driven by demands for higher efficiency, better quality, and new applications.

• Increased Efficiency (lm/W): Ongoing improvements in internal quantum efficiency (IQE), light extraction efficiency, and phosphor technology push luminous efficacy higher, reducing energy consumption for the same light output.
• Improved Color Quality: Development of phosphors and multi-color LED combinations (e.g., RGB, RGBW, violet pump + multi-phosphor) to achieve ultra-high CRI (Ra >95) and excellent color fidelity metrics like TM-30 (Rf, Rg).
• Miniaturization and High Density: The trend towards smaller package sizes (e.g., micro-LEDs, chip-scale packages) enabling higher pixel density for fine-pitch direct-view displays and compact lighting modules.
• Human-Centric Lighting: Tunable white LEDs that can dynamically adjust CCT and intensity to mimic natural daylight cycles, supporting circadian rhythms and well-being.
• Reliability and Lifetime: Focus on understanding and mitigating failure mechanisms (e.g., phosphor thermal quenching, package degradation) to extend useful life, especially under high-temperature operating conditions.
• Smart Integration: Incorporating control electronics, sensors, and communication interfaces directly into LED modules, paving the way for intelligent, connected lighting systems.