LED Component Datasheet - Revision 1 - Lifecycle Phase Analysis - English Technical Document

1. Product Overview

This technical document provides a comprehensive overview of the lifecycle and revision management for a standard Light Emitting Diode (LED) component. The primary focus is on the structured documentation of the component's revision history, ensuring traceability and data integrity throughout its product lifecycle. While specific electrical or photometric parameters are not detailed in the provided source material, the document establishes a critical framework for understanding how technical changes and updates are formally recorded and communicated. This is essential for engineers, procurement specialists, and quality assurance teams who rely on accurate and version-controlled documentation for design-in, manufacturing, and maintenance processes. The core advantage of this structured approach is the mitigation of risk associated with using incorrect or outdated component specifications in electronic assemblies.

2. Lifecycle and Revision Management

The provided data centers on a single, clearly defined lifecycle state for the component.

2.1 Lifecycle Phase Definition

The Lifecycle Phase is explicitly stated as Revision: 1. This indicates that the component documentation has undergone its first formal revision or update since its initial release. In component engineering, a revision change typically signifies modifications that do not alter the form, fit, or function of the part in a way that affects interchangeability. Examples include corrections to typographical errors in the datasheet, clarifications of test conditions, updates to recommended storage guidelines, or minor changes in packaging. Identifying the revision level is crucial for ensuring that all parties in the supply chain are referencing the exact same set of specifications.

2.2 Validity and Release Information

The document specifies an Expired Period: Forever. This denotes that the revision itself, once released, does not have a predetermined expiration date for its validity as a reference document. The information contained within Revision 1 remains the authoritative source unless superseded by a subsequent revision (e.g., Revision 2). The Release Date is precisely recorded as 2012-08-13 13:57:59.0. This timestamp provides an exact point of origin for this revision, enabling precise tracking and audit trails. The use of a timestamp down to the second underscores the importance of version control in technical documentation.

3. Technical Parameters and Specifications

While the core excerpt does not list specific performance parameters, a complete LED datasheet derived from this revision framework would typically include the following sections. The values below are illustrative examples based on industry-standard components.

3.1 Absolute Maximum Ratings

These parameters define the stress limits beyond which permanent damage to the LED may occur. They are not intended for normal operation.

• Forward Current (I_F): 30 mA (continuous).
• Reverse Voltage (V_R): 5 V.
• Junction Temperature (T_j): +125 °C.
• Storage Temperature (T_stg): -40 °C to +100 °C.

3.2 Electro-Optical Characteristics

Measured at T_a=25°C unless otherwise specified, these are the key performance metrics.

• Forward Voltage (V_F): 3.2 V (typical) at I_F = 20 mA. This is the voltage drop across the LED when operating.
• Luminous Intensity (I_v): 5600 mcd (minimum) to 7000 mcd (typical) at I_F = 20 mA. This defines the light output.
• Viewing Angle (2θ_1/2): 120 degrees. This specifies the angular width at which intensity is half the peak value.
• Wavelength / Dominant Wavelength (λ_d): 465 nm (for a blue LED) or 625 nm (for a red LED), subject to binning.

3.3 Thermal Characteristics

• Thermal Resistance, Junction to Ambient (R_θJA): 300 K/W (typical for a small SMD LED). This parameter is critical for calculating the temperature rise during operation.

4. Binning and Classification System

LEDs are typically sorted (binned) after manufacture to ensure consistency. A datasheet will define the allowable ranges for each bin.

• Luminous Intensity Binning: LEDs are sorted into groups based on measured light output (e.g., Bin A: 5600-6000 mcd, Bin B: 6000-6400 mcd, Bin C: 6400-7000 mcd).
• Forward Voltage Binning: Sorted by voltage drop (e.g., Bin V1: 3.0-3.2V, Bin V2: 3.2-3.4V).
• Wavelength/Chromaticity Binning: For colored LEDs, they are binned by dominant wavelength or within specific chromaticity coordinates on the CIE chart to ensure color consistency.

5. Performance Curve Analysis

Graphical data is essential for design.

• I-V (Current-Voltage) Curve: Shows the exponential relationship between forward current and forward voltage, crucial for designing current-limiting circuits.
• Relative Luminous Intensity vs. Forward Current: Demonstrates how light output increases with current, typically in a linear region before saturation.
• Relative Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as temperature increases, a critical factor for thermal management.
• Spectral Distribution Graph: Plots radiant power versus wavelength, showing the peak wavelength and spectral width.

6. Mechanical and Package Information

Physical specifications ensure proper PCB design and assembly.

• Package Dimensions: Detailed mechanical drawing with critical dimensions (length, width, height, lead spacing). For a common SMD LED like a 2835 package, typical dimensions are 2.8mm (L) x 3.5mm (W) x 1.2mm (H).
• Pad Layout (Footprint): Recommended PCB land pattern design for reliable soldering.
• Polarity Identification: Clear marking (e.g., a notch, a green dot, or a cathode mark on the package) to indicate the cathode (-) terminal.

7. Soldering and Assembly Guidelines

Instructions to prevent damage during manufacturing.

• Reflow Soldering Profile: Recommended time-temperature curve (preheat, soak, reflow peak, cooling) compliant with JEDEC or IPC standards. Peak temperature typically should not exceed 260°C for a specified time (e.g., 10 seconds).
• Hand Soldering: If allowed, limits on iron temperature (max 350°C) and contact time (max 3 seconds).
• Cleaning: Compatibility with common cleaning solvents.
• Storage Conditions: Recommend storage in a dry, inert environment (e.g., <40°C/<90% RH) to preserve solderability.

8. Packaging and Ordering Information

• Packaging Format: Tape and reel specifications (e.g., EIA-481 compliant), including reel diameter, tape width, and pocket pitch.
• Quantity per Reel: Standard quantities (e.g., 2000 or 4000 pieces per reel).
• Model Numbering Rule: Explanation of how the part number encodes attributes like color, intensity bin, voltage bin, and packaging option (e.g., LED-2835-B-BIN2-V1-TR).

9. Application Notes and Design Considerations

Guidance for successful implementation.

• Current Limiting: An LED must be driven by a current source or with a series resistor to limit forward current. The resistor value is calculated as R = (V_supply - V_F) / I_F.
• Thermal Management: Even at low power, PCB layout should provide adequate copper area (thermal relief) to dissipate heat, especially for high-brightness LEDs, to maintain performance and longevity.
• ESD (Electrostatic Discharge) Sensitivity: Most LEDs are ESD-sensitive. Proper handling procedures (grounded workstations, wrist straps) and circuit protection (e.g., TVS diodes) may be required.
• Typical Applications: Backlighting for displays, status indicators, decorative lighting, automotive interior lighting, and general illumination in low-power scenarios.

10. Technical Comparison and Differentiation

While this generic datasheet structure is common, specific products differentiate based on:

• Efficiency (Luminous Efficacy): Higher efficacy (lumens per watt) is a key advantage for power-sensitive applications.
• Color Rendering Index (CRI): Critical for white LEDs in lighting applications where accurate color perception is needed.
• Longevity and Lumen Maintenance (L70/L90): Specifications predicting the time until light output degrades to 70% or 90% of initial value under stated conditions.
• Miniaturization: Smaller package sizes (e.g., 0402, 0201) enable denser PCB designs.

11. Frequently Asked Questions (FAQ)

Q: What does "Revision: 1" mean for my design?
A: It confirms you are using the first updated version of the datasheet. Always check if a newer revision exists before finalizing a design to incorporate any changes.

Q: The expired period is "Forever." Does this mean the component will be available forever?
A: No. "Forever" refers to the validity of the revision document itself. Component obsolescence is a separate lifecycle event (e.g., phase-out, discontinued) not indicated here.

Q: How do I select the correct current-limiting resistor?
A: Use the typical V_F from the datasheet and your desired I_F (often 20mA for standard LEDs) in Ohm's Law calculation with your supply voltage. Always verify actual V_F in circuit if precision is needed.

Q: Can I drive the LED with a voltage source directly?
A: Absolutely not. An LED's I-V curve is exponential. A small increase in voltage causes a large, potentially destructive increase in current. Always use a current-limiting mechanism.

12. Practical Use Case Example

Scenario: Designing a status indicator for a consumer router.
The designer selects a green LED with a typical V_F of 3.2V and targets I_F = 15mA for adequate brightness and long life. The router's internal logic supply is 3.3V. Using the formula R = (3.3V - 3.2V) / 0.015A = 6.67Ω. The nearest standard value is 6.8Ω. The power dissipation in the resistor is P = I²R = (0.015^2)*6.8 = 0.00153W, so a tiny 1/10W resistor is sufficient. The PCB footprint is designed according to the datasheet's recommended land pattern, and the assembly house follows the specified reflow profile. The revision number (1) on the datasheet is recorded in the product's Bill of Materials (BOM) for future reference.

13. Operating Principle Introduction

An LED is a semiconductor diode. When a forward voltage exceeding its bandgap energy is applied, electrons in the n-type material recombine with holes in the p-type material at the junction. This recombination releases energy in the form of photons (light), a process called electroluminescence. The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor materials used (e.g., Gallium Arsenide Phosphide for red, Indium Gallium Nitride for blue). White LEDs are typically blue LEDs coated with a phosphor that converts some blue light to yellow, resulting in a broad spectrum perceived as white.

14. Industry Trends and Developments

The LED industry continues to evolve rapidly. Key trends include:

• Increased Efficiency: Ongoing R&D pushes luminous efficacy higher, reducing energy consumption for lighting.
• Miniaturization and Integration: Development of micro-LEDs and chip-scale package (CSP) LEDs for ultra-high-resolution displays and compact devices.
• Improved Color Quality: Advances in phosphor technology and multi-color LED arrays (e.g., RGB, RGBA) enable wider color gamuts and higher CRI for specialized lighting.
• Smart and Connected Lighting: Integration of control circuitry and communication interfaces (like Zigbee or Bluetooth) directly with LED modules.
• Reliability and Lifetime Predictions: More sophisticated testing and modeling to provide accurate lifetime data (L90, L70) under various operating conditions.
• Sustainability: Focus on reducing the use of rare-earth materials in phosphors and improving recyclability.

This document, rooted in its specific revision lifecycle, serves as a stable foundation within this dynamic technological landscape, ensuring that the fundamental specifications and change history are meticulously documented for reliable application.