LED Component Datasheet - Lifecycle Phase: Revision 1 - Release Date: 2013-03-15 - English Technical Document

1. Product Overview

This technical datasheet pertains to a specific revision of an LED component. The primary information provided indicates the component is in its first revision (Revision 1) and was officially released on March 15, 2013. The lifecycle phase is marked as "Revision," signifying an update or modification from a previous version. The "Expired Period" is noted as "Forever," which typically implies the datasheet remains valid indefinitely for this specific revision or that the component has no planned obsolescence date for this version. This document serves as the definitive source for the electrical, optical, and mechanical specifications of this component revision, intended for engineers, designers, and procurement specialists involved in product development and manufacturing.

2. Technical Parameters Deep Objective Interpretation

While the provided snippet is limited, a comprehensive datasheet for an LED component in Revision 1 would contain detailed technical parameters. These are critical for proper circuit design and ensuring performance expectations are met.

2.1 Photometric and Color Characteristics

A full datasheet would specify key photometric parameters. The dominant wavelength or correlated color temperature (CCT) defines the color of light emitted, such as cool white, warm white, or a specific monochromatic color like red or blue. The luminous flux, measured in lumens (lm), indicates the total perceived light output. Chromaticity coordinates (e.g., on the CIE 1931 diagram) provide a precise definition of color point. Color rendering index (CRI) may be specified for white LEDs, indicating how accurately the light source reveals the colors of objects compared to a natural light source. The viewing angle, typically given as the angle at which luminous intensity is half of the maximum (e.g., 120 degrees), describes the spatial distribution of light.

2.2 Electrical Parameters

Electrical specifications are fundamental for driver design. The forward voltage (Vf) is the voltage drop across the LED at a specified test current. It is crucial for determining the power supply requirements. The forward current (If) is the recommended operating current, directly influencing light output and lifetime. Maximum ratings for reverse voltage, peak forward current, and power dissipation define the absolute limits beyond which permanent damage may occur. The dynamic resistance may also be provided for more advanced modeling in pulsed or varying current applications.

2.3 Thermal Characteristics

LED performance and longevity are heavily dependent on thermal management. The junction-to-ambient thermal resistance (RθJA) quantifies how effectively heat is transferred from the semiconductor junction to the surrounding environment. A lower value indicates better heat dissipation. The maximum junction temperature (Tj max) is the highest temperature the LED chip can withstand without degradation. Operating the LED below this temperature, typically through adequate heatsinking, is essential for maintaining luminous flux, color stability, and achieving the rated lifetime (often defined as L70 or L50, the time until lumen output degrades to 70% or 50% of initial value).

3. Binning System Explanation

Manufacturing variations necessitate a binning system to categorize LEDs based on key parameters, ensuring consistency within a production batch.

3.1 Wavelength/Color Temperature Binning

LEDs are sorted into bins based on their precise chromaticity coordinates or dominant wavelength. This ensures that products using multiple LEDs have uniform color appearance. For white LEDs, bins are defined by ranges on the CIE chart and/or by correlated color temperature (CCT) ranges (e.g., 3000K ± 150K).

3.2 Luminous Flux Binning

LEDs are also binned according to their light output at a standard test current. A bin code (e.g., Flux Bin A, B, C) corresponds to a minimum and maximum luminous flux range. This allows designers to select LEDs that meet specific brightness requirements for their application.

3.3 Forward Voltage Binning

Forward voltage (Vf) is another parameter subject to variation. Binning by Vf helps in designing efficient driver circuits, especially when connecting multiple LEDs in series, as it minimizes current imbalance and power loss.

4. Performance Curve Analysis

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

4.1 Current-Voltage (I-V) Characteristic Curve

The I-V curve illustrates the nonlinear relationship between forward current and forward voltage. It shows the turn-on voltage and how Vf increases with current. This curve is essential for selecting an appropriate current-limiting method (resistor, constant current driver).

4.2 Temperature Dependency

Graphs typically show how forward voltage decreases with increasing junction temperature (a negative temperature coefficient). More importantly, they depict the relative luminous flux as a function of junction temperature, showing the drop in light output as temperature rises. This underscores the need for effective thermal design.

4.3 Spectral Power Distribution

The spectral distribution plot shows the relative intensity of light emitted at each wavelength. For monochromatic LEDs, it shows the peak wavelength and spectral width (FWHM). For white LEDs (often phosphor-converted), it shows the blue pump LED peak and the broader phosphor emission spectrum.

5. Mechanical and Packaging Information

Physical specifications ensure correct PCB layout and assembly.

5.1 Dimensional Outline Drawing

A detailed mechanical drawing provides all critical dimensions: length, width, height, lens shape, and any protrusions. Tolerances are specified for each dimension.

5.2 Pad Layout and Footprint Design

The recommended PCB land pattern (footprint) is provided, including pad size, shape, and spacing. This is vital for solder joint reliability and proper thermal connection to the PCB.

5.3 Polarity Identification

The method for identifying the anode and cathode is clearly indicated. This is usually via a marking on the component body (e.g., a notch, dot, or cut corner) or an asymmetric pad design.

6. Soldering and Assembly Guidelines

Proper handling and assembly are critical to reliability.

6.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow peak temperature, and cooling rates. Maximum temperature and time above liquidus are specified to prevent damage to the LED package and internal materials.

6.2 Precautions and Handling

Guidelines cover ESD (electrostatic discharge) protection, as LEDs are sensitive to static electricity. Recommendations for storage conditions (temperature, humidity) are given to preserve solderability and prevent moisture absorption (MSL rating).

7. Packaging and Ordering Information

Information for logistics and procurement.

7.1 Packaging Specifications

Details on how the LEDs are supplied: reel type (e.g., 7-inch, 13-inch), tape width, pocket spacing, and quantity per reel. Orientation within the tape is specified.

7.2 Labeling and Part Numbering

The labeling on the reel or box includes the full part number, quantity, date code, and lot number. The part number itself is a code that encapsulates key attributes like color, flux bin, voltage bin, and package type.

8. Application Recommendations

Guidance for implementing the component in a design.

8.1 Typical Application Circuits

Schematics for basic drive circuits are shown, such as using a series resistor with a constant voltage source or employing a dedicated constant-current LED driver IC for better efficiency and stability.

8.2 Design Considerations

Key considerations include thermal management (PCB copper area, thermal vias, possible external heatsink), optical design (lens selection, secondary optics), and electrical layout to minimize noise and ensure stable current.

9. Technical Comparison

While specific to this revision, advantages might include improved luminous efficacy (lumens per watt) compared to the previous revision or competing products, better color consistency (tighter binning), enhanced reliability data (longer L70 lifetime), or a more compact package size enabling higher-density designs. The "Revision 1" status itself indicates refinements and optimizations based on feedback or advancements from the initial release.

10. Frequently Asked Questions

Common queries based on technical parameters include: "What is the recommended drive current for maximum lifetime?" (Answer: Typically at or below the nominal If). "How does the luminous flux degrade over time?" (Refer to the lifetime curves and L70/L50 ratings). "Can I drive this LED with a voltage source?" (Answer: Not recommended without a current-limiting mechanism due to the LED's exponential I-V characteristic). "What is the effect of PWM dimming on color?" (Typically minimal if frequency is high enough, but datasheet may specify).

11. Practical Use Cases

Based on common LED applications, this component could be used in: General lighting modules (downlights, panel lights), where consistent color and high efficacy are key. Automotive interior lighting (dome lights, accent lighting), requiring reliability over a wide temperature range. Backlighting units for LCD displays, where uniform brightness is critical. Decorative and architectural lighting, leveraging its specific color point. Consumer electronics indicator lights, utilizing its compact size.

12. Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light when an electric current passes through them. This phenomenon, called electroluminescence, occurs when electrons recombine with electron holes within the device, releasing energy in the form of photons. The color of the light is determined by the energy band gap of the semiconductor material used. For white LEDs, a blue or ultraviolet LED chip is coated with a phosphor material that absorbs some of the blue/UV light and re-emits it as yellow or a broader spectrum, combining to produce white light.

13. Development Trends

The LED industry continues to evolve. Trends include the pursuit of ever-higher luminous efficacy to reduce energy consumption. Improvements in color quality, such as higher CRI and R9 (saturated red) values, for applications demanding excellent color rendering. The development of novel phosphor systems for more stable color over lifetime and temperature. Miniaturization of packages for ultra-high-density applications. The integration of control electronics directly with the LED chip or package, leading to "smart" or "connected" LEDs. Increased focus on reliability and lifetime prediction models, especially for demanding applications like automotive headlights.