LED Component Technical Datasheet - Lifecycle Revision 2 - Release Date 2014-12-11 - English Technical Document

1. Product Overview

This technical datasheet provides comprehensive information for an LED component, focusing on its lifecycle management and technical specifications. The document is structured to offer engineers, designers, and procurement specialists with the essential data required for integration, qualification, and long-term support of the component within electronic systems. The core information presented establishes the document's revision status and its perpetual validity for reference purposes.

The primary purpose of this datasheet is to serve as a definitive source for the component's technical parameters and lifecycle information. It is designed to support decision-making in product design, manufacturing process planning, and supply chain management. The data contained herein is critical for ensuring compatibility, reliability, and performance consistency in end applications.

2. Lifecycle and Document Control Information

The document control section is paramount for understanding the validity and authority of the technical data presented.

2.1 Lifecycle Phase

The component and its associated documentation are currently in the Revision phase. This indicates that the product design and specifications are stable, mature, and in active production. The revision number for this document is 2, signifying it is the second official release of this technical datasheet. Revisions typically incorporate corrections, clarifications, or updates to parameters based on ongoing production feedback or refined testing methodologies.

2.2 Document Validity

The Expired Period for this document is stated as Forever. This designation means that this specific revision of the datasheet remains valid indefinitely for reference to the component version it describes. It does not expire or become obsolete unless a new revision is issued to supersede it. This is common for documentation of mature, standardized components.

2.3 Release Information

The official Release Date for this revision (Revision 2) is 2014-12-11 18:36:47.0. This timestamp provides a clear historical record of when this specific set of specifications was finalized and published. This information is crucial for version control and for tracing the component's specification history.

3. Technical Parameters Deep Objective Interpretation

While the provided PDF excerpt focuses on document metadata, a complete LED datasheet would contain detailed technical parameters. The following sections explain the typical parameters found in such a document and their significance.

3.1 Photometric Characteristics

Photometric characteristics define the light output of the LED. Key parameters include luminous flux (measured in lumens, lm), which quantifies the perceived power of light. Luminous intensity (measured in candela, cd) describes the light output in a specific direction. Correlated Color Temperature (CCT), measured in Kelvin (K), defines whether the white light appears warm, neutral, or cool. For colored LEDs, the dominant wavelength (measured in nanometers, nm) is specified. Chromaticity coordinates (e.g., on the CIE 1931 chart) provide a precise definition of the color point. Understanding these parameters is essential for achieving the desired brightness and color quality in the application.

3.2 Electrical Parameters

Electrical parameters are critical for circuit design. The forward voltage (Vf) is the voltage drop across the LED when operating at a specified forward current (If). It is crucial for determining the power supply requirements. The forward current rating (If) is the maximum continuous current the LED can handle, directly influencing light output and lifetime. Reverse voltage (Vr) specifies the maximum voltage that can be applied in the reverse direction without damaging the device. These parameters ensure the LED is driven within its safe operating area (SOA).

3.3 Thermal Characteristics

LED performance and longevity are heavily dependent on thermal management. The junction temperature (Tj) is the temperature at the semiconductor chip itself. The thermal resistance (Rth j-s or Rth j-a), measured in degrees Celsius per watt (°C/W), indicates how effectively heat is transferred from the junction to the solder point (s) or ambient (a). A lower thermal resistance is desirable. Maximum junction temperature (Tj max) must not be exceeded to prevent accelerated degradation or catastrophic failure. Proper heat sinking is designed based on these values.

4. Binning System Explanation

Manufacturing variations lead to slight differences between individual LEDs. Binning is the process of sorting LEDs into groups (bins) based on key parameters to ensure consistency.

4.1 Wavelength/Color Temperature Binning

LEDs are binned according to their chromaticity coordinates or CCT. For white LEDs, bins are defined by small quadrangles on the CIE chart or by CCT ranges (e.g., 3000K ± 100K). For monochromatic LEDs, bins are defined by dominant wavelength ranges (e.g., 525nm ± 2nm). This ensures color uniformity within a batch of products.

4.2 Luminous Flux Binning

LEDs are sorted based on their light output at a standard test current. They are grouped into flux bins (e.g., Bin A: 100-110 lm, Bin B: 90-100 lm). This allows designers to select LEDs that meet specific brightness requirements and helps maintain consistent luminance across a product.

4.3 Forward Voltage Binning

LEDs are also binned by their forward voltage (Vf) at a specified test current. Common bins might be Vf1: 2.8V - 3.0V, Vf2: 3.0V - 3.2V, etc. This is important for designing efficient driver circuits, especially when connecting multiple LEDs in series, to minimize current variation and power loss.

5. Performance Curve Analysis

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

5.1 Current-Voltage (I-V) Characteristic Curve

This curve plots the relationship between forward current and forward voltage. It is non-linear, showing a threshold voltage below which very little current flows. The curve's slope in the operating region relates to the dynamic resistance. This graph is essential for understanding driver compatibility and for predicting voltage drops in circuit simulations.

5.2 Temperature Characteristics

Several graphs illustrate temperature dependence. The luminous flux vs. junction temperature curve typically shows output decreasing as temperature increases. The forward voltage vs. junction temperature curve usually shows a negative coefficient (Vf decreases as Tj increases). These curves are vital for designing systems that maintain performance over the intended operating temperature range.

5.3 Spectral Power Distribution (SPD)

The SPD graph shows the relative intensity of light emitted at each wavelength. For white LEDs (typically phosphor-converted), it shows a blue peak from the LED chip and a broader yellow/red peak from the phosphor. This graph is used to calculate color rendering index (CRI), CCT, and other colorimetric properties.

6. Mechanical and Packaging Information

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

6.1 Dimensional Outline Drawing

A detailed mechanical drawing provides all critical dimensions: length, width, height, lead spacing, and component tolerances. This drawing is used for creating PCB footprints and for checking clearance in the assembly.

6.2 Pad Layout Design

The recommended PCB land pattern (pad geometry and size) is provided to ensure reliable solder joint formation during reflow soldering. It accounts for component tolerances and solder fillet formation.

3.3 Polarity Identification

The method for identifying the anode and cathode is clearly indicated, usually via a marking on the component body (e.g., a notch, dot, or cut corner) or via asymmetrical lead shapes. Correct polarity is essential for circuit operation.

7. Soldering and Assembly Guidelines

These instructions preserve LED integrity during manufacturing.

7.1 Reflow Soldering Profile

A recommended temperature profile for reflow soldering is provided, including preheat, soak, reflow (peak temperature), and cooling rates. Maximum temperature limits and time-above-liquidus are specified to prevent thermal damage to the LED package or internal die.

7.2 Precautions and Handling

Guidelines include warnings against applying mechanical stress to the LED lens, using proper ESD (electrostatic discharge) precautions, and avoiding contamination of the optical surface. Cleaning methods compatible with the package material may also be specified.

7.3 Storage Conditions

Recommended storage temperature and humidity ranges are provided to prevent degradation of the component before use, such as moisture absorption which can cause \"popcorning\" during reflow.

8. Packaging and Ordering Information

This section details how the product is supplied.

8.1 Packaging Specifications

The tape and reel dimensions, pocket size, and orientation are specified for automated placement equipment. Quantities per reel or per tube are stated.

8.2 Labeling Information

The content of the packaging label is described, typically including part number, quantity, lot/batch code, date code, and binning information.

8.3 Part Numbering System

The model naming convention is explained, showing how the part number encodes key attributes like color, flux bin, voltage bin, packaging type, and sometimes special features.

9. Application Recommendations

Guidance for implementing the component effectively.

9.1 Typical Application Circuits

Schematics for basic drive circuits are often included, such as a simple series resistor circuit for constant voltage supplies or recommendations for using constant current drivers. Considerations for series/parallel connections are discussed.

9.2 Design Considerations

Key design advice includes the importance of thermal management (PCB copper area, thermal vias), optical design (lens selection, spacing), and electrical design (inrush current protection, dimming compatibility).

10. Technical Comparison and Differentiation

While not always explicitly stated in a single-datasheet, the parameters define the component's position. Advantages may include high luminous efficacy (lumens per watt), excellent color consistency (tight binning), robust reliability data (high L70/L90 lifetime ratings), or a compact form factor enabling high-density designs.

11. Frequently Asked Questions (FAQ)

Common queries based on technical parameters are addressed.

Q: Can I drive this LED with a voltage source?
A: While possible with a series current-limiting resistor, a constant current driver is strongly recommended for stable light output and long-term reliability, as the LED's forward voltage varies with temperature and bin.

Q: What causes the light output to decrease over time?
A: Gradual degradation of the semiconductor materials and phosphors (if present) leads to lumen depreciation. Operating the LED at or below its rated current and maintaining a low junction temperature through effective heat sinking are the primary ways to maximize lifetime.

Q: How important is the thermal resistance value?
A: Extremely important. It is the key metric for calculating the temperature rise of the LED junction above the ambient or board temperature for a given power dissipation. Exceeding Tj max drastically shortens lifespan.

12. Practical Use Case Examples

Case 1: Architectural Linear Lighting: For a continuous run of LED strips, selecting LEDs from a single, tight flux and color bin is critical to avoid visible brightness or color shifts along the length. The high reliability and defined lifetime support long-term maintenance planning for installed fixtures.

Case 2: Automotive Interior Lighting: LEDs used in dashboard backlighting or ambient lighting must operate reliably across a wide temperature range (-40°C to +85°C or higher). The datasheet's temperature derating curves for flux and forward voltage are used to design circuits that compensate for these changes, ensuring consistent appearance.

13. Principle of Operation 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 yellow phosphor; the mixture of blue and yellow light appears white to the human eye.

14. Technology Trends

The LED industry continues to evolve. Key trends include the ongoing increase in luminous efficacy, reducing the energy consumption for a given light output. There is a strong focus on improving color quality, such as achieving higher Color Rendering Index (CRI) and more precise color tuning. Miniaturization persists, enabling ever-smaller pixel pitches in direct-view displays. Furthermore, the integration of smart features, such as built-in drivers or color control circuitry, is becoming more common. Research into novel materials, like perovskites for next-generation displays and lighting, is also an active area of development.