LED Component Datasheet - Lifecycle Revision 2 - Release Date 2014-12-08 - English Technical Document

1. Product Overview

This technical datasheet provides critical lifecycle and release information for a specific electronic component, likely an LED or similar optoelectronic device. The core focus of this document is to establish the official revision status and release timeline, which are fundamental for supply chain management, quality control, and design traceability. Understanding the lifecycle phase ensures that engineers and procurement specialists are utilizing the correct and most current version of the component in their designs and production runs.

The document indicates a stable, finalized revision of the product specification. The "Forever" expired period suggests this is a definitive release version intended for long-term production use, as opposed to a preliminary or draft document. The precise timestamp for the release allows for accurate version control and is crucial when investigating field issues or performing audits.

2. Technical Parameters Deep Objective Interpretation

While the provided PDF excerpt does not list specific photometric, electrical, or thermal parameters, the presence of a formal revision number and release date implies the existence of a comprehensive set of technical specifications in the full datasheet. These typically include, but are not limited to, the following categories which must be considered for any component integration.

2.1 Photometric Characteristics

For an LED, key photometric parameters define its light output. Luminous flux, measured in lumens (lm), indicates the total perceived power of light emitted. Luminous intensity, often given in millicandelas (mcd) at a specific viewing angle, describes the spatial distribution of light. The dominant wavelength or correlated color temperature (CCT) defines the color of the emitted light, critical for applications requiring specific white points or saturated colors. Color Rendering Index (CRI) is another vital parameter for white LEDs, indicating how naturally colors appear under the light source.

2.2 Electrical Parameters

Electrical specifications are paramount for circuit design. The forward voltage (Vf) at a given test current is essential for determining the required drive voltage and power supply design. The forward current (If) rating specifies the maximum continuous current the device can handle, directly influencing light output and longevity. Reverse voltage (Vr) indicates the maximum voltage the device can withstand in the non-conducting direction. Dynamic resistance and capacitance are also important for high-frequency switching applications.

2.3 Thermal Characteristics

Thermal management is critical for LED performance and reliability. The junction-to-ambient thermal resistance (RθJA) quantifies how effectively heat is dissipated from the semiconductor junction to the surrounding environment. This parameter directly impacts the maximum allowable operating current and the LED's lifetime. The maximum junction temperature (Tj max) is the absolute upper limit for the semiconductor's operating temperature, beyond which rapid degradation or failure occurs. Proper heatsinking is calculated based on these values.

3. Binning System Explanation

Manufacturing variations necessitate a binning system to categorize components into groups with tightly controlled parameters. This ensures consistency in end-product performance.

3.1 Wavelength / Color Temperature Binning

LEDs are sorted into bins based on their peak wavelength (for monochromatic LEDs) or correlated color temperature (for white LEDs). This binning ensures that all LEDs used in an assembly, such as a display backlight or architectural lighting fixture, produce nearly identical color, preventing visible color shifts or uneven illumination.

3.2 Luminous Flux Binning

Components are also binned according to their light output at a standard test current. This allows designers to select parts that meet specific brightness requirements and ensures uniformity in applications where multiple LEDs are used in parallel, such as in light panels or automotive tail lights.

3.3 Forward Voltage Binning

Binning by forward voltage helps in designing efficient driver circuits. Grouping LEDs with similar Vf characteristics allows for simpler, more stable constant-current drive topologies, as the voltage drop across each LED in a series string will be more uniform, leading to balanced current sharing.

4. Performance Curve Analysis

Graphical data in a datasheet provides deeper insight into component behavior under varying conditions.

4.1 Current-Voltage (I-V) Characteristic Curve

The I-V curve illustrates the relationship between forward current and forward voltage. It shows the turn-on voltage and the dynamic resistance in the operating region. This curve is essential for selecting current-limiting resistors or designing constant-current drivers, as small changes in voltage can lead to large changes in current (and thus light output) due to the diode's exponential characteristic.

4.2 Temperature Characteristics

Graphs typically show how key parameters degrade with increasing junction temperature. Luminous flux output generally decreases as temperature rises. Forward voltage also decreases with increasing temperature. Understanding these relationships is crucial for designing systems that maintain consistent performance over the intended operating temperature range.

4.3 Spectral Power Distribution

For color-critical applications, a spectral distribution graph is vital. It plots the relative intensity of light emitted at each wavelength. This graph reveals the purity of a colored LED (narrow peak) or the phosphor conversion profile of a white LED, including potential cyan or red deficits which affect CRI.

5. Mechanical and Packaging Information

Physical specifications ensure proper fit and function on the printed circuit board (PCB).

5.1 Dimensional Outline Drawing

A detailed mechanical drawing provides exact dimensions including length, width, height, and any curvature or chamfer. Tolerances are specified for all critical dimensions. This drawing is used to create the PCB footprint and check for mechanical clearance in the final assembly.

5.2 Pad Layout Design

The recommended PCB land pattern (footprint) is provided, showing the size, shape, and spacing of the copper pads. Adhering to this design is critical for achieving reliable solder joints, proper alignment, and effective thermal transfer from the component to the PCB.

5.3 Polarity Identification

The datasheet clearly indicates the anode and cathode terminals. This is typically shown via a diagram marking a notch, a beveled corner, a dot, or different lead lengths. Incorrect polarity will prevent the device from operating and may cause damage.

6. Soldering and Assembly Guidelines

Proper handling and processing are required to maintain component integrity.

6.1 Reflow Soldering Profile

A detailed temperature profile is provided, specifying preheat, soak, reflow peak temperature, and cooling rates. The maximum peak temperature and time above liquidus are critical limits that must not be exceeded to avoid damaging the LED's internal structure, epoxy lens, or wire bonds.

6.2 Precautions and Handling

Guidelines include warnings against applying mechanical stress to the lens, exposure to excessive electrostatic discharge (ESD), and the use of inappropriate cleaning solvents. Recommendations for storage conditions (typically low humidity and moderate temperature) are also provided to prevent moisture absorption which can cause "popcorning" during reflow.

7. Packaging and Ordering Information

This section details how the components are supplied and how to specify them.

7.1 Packaging Specifications

Information includes the tape width, pocket spacing, and reel diameter for tape-and-reel packaging, or the tube quantity and dimensions for stick magazine packaging. This data is necessary for automated pick-and-place machine programming.

7.2 Model Number Naming Rules

The part number is typically a code that encapsulates key attributes such as package size, color, flux bin, voltage bin, and sometimes special features. Decoding this part number allows for precise identification and ordering of the exact component variant required for the design.

8. Application Suggestions

General guidance on where and how to effectively use the component.

8.1 Typical Application Scenarios

Based on its implied characteristics, a component like this could be suited for backlighting units in consumer electronics, indicator lights in appliances and automotive dashboards, decorative lighting, or general illumination in compact fixtures. The specific application depends on the actual photometric and electrical data.

8.2 Design Considerations

Key design considerations include providing adequate current limiting, implementing proper thermal management via PCB copper pours or external heatsinks, ensuring optical design (e.g., use of lenses or diffusers) matches the LED's viewing angle, and protecting against voltage transients and ESD.

9. Technical Comparison

While a direct comparison cannot be made without a specific competitor's data, the revision lifecycle information suggests this component has reached a mature and stable specification. Advantages may include well-characterized performance, proven reliability in the field, wide availability in the supply chain, and extensive application notes or reference designs from the manufacturer, reducing design risk compared to a newly released component.

10. Frequently Asked Questions

Common questions based on technical parameters include:

• Q: What does "Revision: 2" mean for my design?
  
  A: It indicates this is the second official release of the datasheet. You should always use the latest revision to ensure your design is based on the most accurate and up-to-date specifications. Check if any parameters have changed from Revision 1.
• Q: The "Expired Period" is "Forever." Does this mean the component will never be obsolete?
  
  A: No. "Forever" in this context likely means the datasheet itself does not have an expiration date for its validity. The component's production lifecycle (active, not recommended for new designs, obsolete) is a separate matter managed by the manufacturer's product change notifications (PCNs).
• Q: How do I use the release date information?
  
  A: The release date is a key identifier. It helps in version control, especially when communicating with the manufacturer about technical support or quality issues. Always reference the full part number and datasheet release date.

11. Practical Use Cases

Case Study 1: Consumer Electronics Backlighting

A designer is creating a new tablet. They select this LED based on its size, efficiency, and color point. The stable revision (2) gives them confidence that the optical performance will not change during their multi-year production cycle. They use the I-V curve to design an efficient constant-current driver and the thermal resistance data to model the temperature rise in the slim enclosure.

Case Study 2: Industrial Indicator Panel

An engineer needs a highly reliable status indicator for a factory machine. The "Forever" datasheet validity and mature revision suggest a reliable, long-standing component. They use the maximum ratings and soldering profile to design a robust PCB that can withstand the industrial environment and assembly process.

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. White LEDs are typically created by using a blue LED chip coated with a yellow phosphor, which mixes to produce white light, or by combining red, green, and blue (RGB) LEDs.

13. Development Trends

The LED industry continues to evolve with several clear trends. Efficiency, measured in lumens per watt (lm/W), is constantly improving, reducing energy consumption for the same light output. Miniaturization allows for higher density arrays and new form factors. Color quality, particularly for white LEDs, is improving with higher CRI values and more consistent color rendering. Smart and connected lighting, integrating sensors and controls, is becoming more prevalent. Furthermore, there is a strong focus on reliability and longevity, with manufacturers providing more detailed lifetime projections (L70, L90) under various operating conditions. The concept of the datasheet itself is evolving, with some manufacturers offering interactive online tools and detailed simulation models alongside traditional PDF documents.