LED Component Datasheet - Lifecycle Phase Revision 3 - Release Date 2014-12-05 - English Technical Document

1. Product Overview

This technical document provides comprehensive specifications and guidelines for a light-emitting diode (LED) component. The primary function of this component is to emit light when an electrical current is passed through it. LEDs are semiconductor devices that convert electrical energy into visible light, offering advantages in efficiency, longevity, and reliability compared to traditional lighting solutions. The core advantages of this specific component include its stable performance over a long operational lifespan and consistent output characteristics as defined by its lifecycle phase and revision status. The target market for this component spans a wide range of applications, from general illumination and backlighting for displays to indicator lights in consumer electronics and industrial equipment. The consistent revision history indicates a mature and stable product design suitable for applications requiring dependable, long-term performance.

2. In-Depth Technical Parameter Analysis

While the provided PDF excerpt focuses on document metadata, a typical LED datasheet contains several critical technical parameter sections. The following analysis is based on standard industry specifications for components of this nature.

2.1 Photometric and Color Characteristics

The photometric characteristics define the light output of the LED. Key parameters include luminous flux, measured in lumens (lm), which indicates the total perceived power of light emitted. The correlated color temperature (CCT), measured in Kelvin (K), describes the color appearance of the white light emitted, ranging from warm white (2700K-3000K) to cool white (5000K-6500K). For colored LEDs, the dominant wavelength, measured in nanometers (nm), specifies the perceived color. Chromaticity coordinates (e.g., CIE x, y) provide a precise numerical description of the color point on the standard color space diagram. The color rendering index (CRI) is a measure of how accurately the light source reveals the colors of objects compared to a natural light source, with higher values (closer to 100) being preferable for applications requiring true color perception.

2.2 Electrical Parameters

Electrical parameters are crucial for circuit design. The forward voltage (Vf) is the voltage drop across the LED when it is operating at its specified current. It is typically specified at a particular test current (e.g., 20mA, 150mA) and can vary with temperature and between individual units. The forward current (If) is the recommended operating current for the LED, which directly influences light output and device longevity. Exceeding the maximum forward current can lead to premature failure. The reverse voltage (Vr) is the maximum voltage the LED can withstand when biased in the non-conducting direction. The power dissipation is calculated as the product of forward voltage and forward current, and it determines the thermal load on the component.

2.3 Thermal Characteristics

LED performance and lifespan are highly dependent on operating temperature. The junction temperature (Tj) is the temperature at the semiconductor chip itself. Maintaining a low junction temperature is critical for long life and stable light output. The thermal resistance from junction to ambient (RθJA) or junction to solder point (RθJS) quantifies how effectively heat is transferred away from the LED chip. A lower thermal resistance value indicates better heat dissipation capability. Designers must ensure proper thermal management, such as using an adequate heatsink or thermal pad, to keep the junction temperature within the specified maximum limit, often around 85°C to 125°C for reliable operation.

3. Binning System Explanation

Due to manufacturing variations, LEDs are sorted into performance bins to ensure consistency for the end-user.

3.1 Wavelength/Color Temperature Binning

LEDs are binned according to their chromaticity coordinates or dominant wavelength. A binning structure, often defined by a MacAdam ellipse step (e.g., 3-step, 5-step), groups LEDs with very similar color characteristics together. A smaller ellipse step indicates tighter color consistency within the bin. This is essential for applications where uniform color appearance is critical, such as in display backlighting or architectural lighting arrays.

3.2 Luminous Flux Binning

Luminous flux bins categorize LEDs based on their light output at a standard test current. Bins are typically defined by a minimum and maximum luminous flux value (e.g., 100-105 lm, 105-110 lm). Selecting LEDs from the same flux bin ensures uniform brightness in an assembly.

3.3 Forward Voltage Binning

Forward voltage bins group LEDs with similar Vf characteristics. This is important for designs where multiple LEDs are connected in series, as mismatched Vf values can lead to uneven current distribution and brightness if not properly managed by the driving circuit.

4. Performance Curve Analysis

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

4.1 Current-Voltage (I-V) Characteristic Curve

The I-V curve shows the relationship between the forward current through the LED and the voltage across its terminals. It is non-linear, exhibiting a threshold voltage below which very little current flows. The curve's slope in the operating region relates to the dynamic resistance of the LED. This curve is essential for designing constant-current drivers.

4.2 Temperature Dependency

Graphs typically show how key parameters change with temperature. Luminous flux generally decreases as junction temperature increases. Forward voltage typically decreases with rising temperature for most LED types. Understanding these relationships is vital for designing systems that maintain performance over the intended operating temperature range.

4.3 Spectral Power Distribution (SPD)

The SPD graph plots the relative intensity of light emitted at each wavelength. For white LEDs (often blue chips with phosphor conversion), it shows the blue peak from the chip and the broader emission spectrum from the phosphor. This graph is used to calculate colorimetric data like CCT and CRI.

5. Mechanical and Package Information

The physical package ensures reliable electrical connection and thermal performance.

5.1 Dimensional Outline Drawing

A detailed mechanical drawing provides all critical dimensions of the LED package, including length, width, height, and any lens or dome geometry. Tolerances for each dimension are specified. This information is necessary for PCB footprint design and ensuring proper fit within the final product assembly.

5.2 Pad Layout and Solder Pad Design

The recommended PCB land pattern (solder pad geometry and size) is provided to ensure good solder joint formation during reflow soldering. This includes the size, shape, and spacing of the anode and cathode pads. A proper land pattern is critical for mechanical strength, electrical conductivity, and thermal transfer to the PCB.

5.3 Polarity Identification

The method for identifying the anode (positive) and cathode (negative) terminals is clearly indicated. Common methods include a marking on the package (such as a notch, dot, or beveled corner), different lead lengths, or a specific pad shape on the footprint diagram. Correct polarity is essential for device operation.

6. Soldering and Assembly Guidelines

Proper handling and assembly are critical to reliability.

6.1 Reflow Soldering Profile

A recommended reflow soldering temperature profile is provided. This graph shows temperature versus time, defining key zones: preheat, soak, reflow (with peak temperature), and cooling. Maximum temperature limits and time-above-liquidus are specified to prevent thermal damage to the LED package, lens, or internal materials (like silicone or phosphor).

6.2 Handling and Storage Precautions

LEDs are sensitive to electrostatic discharge (ESD). Guidelines include using ESD-safe workstations, wrist straps, and packaging. Moisture sensitivity level (MSL) may be specified, indicating how long the component can be exposed to ambient humidity before it must be baked prior to soldering. Storage conditions (temperature and humidity ranges) are also defined to preserve solderability and performance.

7. Packaging and Ordering Information

Information for procurement and logistics.

7.1 Packaging Specifications

The unit packaging is described (e.g., tape and reel, tube, tray). Key details include the reel dimensions, number of components per reel, tape width, and pocket pitch. This is necessary for automated pick-and-place machine setup.

7.2 Labeling and Part Numbering System

The part number structure is decoded. It typically includes codes for the product family, color, flux bin, voltage bin, package type, and sometimes special features. Understanding this allows for precise ordering of the required performance combination. Labels on reels or boxes contain this part number, quantity, lot number, and date code for traceability.

8. Application Recommendations

Guidance for implementing the component effectively.

8.1 Typical Application Circuits

Schematic examples show common drive configurations, such as a simple series resistor for low-current indicators or constant-current driver circuits for higher-power applications. Design equations for selecting the current-limiting resistor based on supply voltage and desired LED current are often included.

8.2 Design Considerations

Key considerations include thermal management (PCB copper area, vias, external heatsinks), optical design (lens selection, reflectors, diffusers for desired beam pattern), and electrical design (ensuring the driver can provide stable current, protecting against voltage transients or reverse polarity).

9. Technical Comparison and Differentiation

While specific competitor names are omitted, the inherent advantages of this LED technology can be highlighted. Compared to older LED generations or alternative lighting like incandescent bulbs, this component likely offers higher luminous efficacy (more lumens per watt), longer operational lifetime (often rated at L70 or L50, meaning time until light output degrades to 70% or 50% of initial), better color consistency due to advanced binning, and a more compact form factor enabling sleeker product designs.

10. Frequently Asked Questions (FAQ)

Answers to common technical queries based on the datasheet parameters.

Q: What does 'Lifecycle Phase: Revision 3' imply?
A: It indicates this is the third major revision of the product's technical documentation. Revisions typically incorporate design improvements, updated test data, or clarifications. 'Revision 3' suggests a mature, stable product with a well-established specification.

Q: How do I select the right current-limiting resistor?
A: Use Ohm's Law: R = (Vsupply - Vf) / If. Where Vsupply is your circuit's voltage, Vf is the LED's forward voltage from the datasheet (use the typical or maximum value for a conservative design), and If is your desired forward current. Ensure the resistor's power rating is sufficient: P = (Vsupply - Vf) * If.

Q: Why is thermal management so important for LEDs?
A: Excessive junction temperature accelerates the degradation of the LED chip and phosphor (in white LEDs), leading to a faster decline in light output (lumen depreciation) and a potential shift in color over time. It can also reduce immediate efficiency and, in extreme cases, cause catastrophic failure.

Q: Can I drive this LED with a voltage source directly?
A: No. LEDs are current-driven devices. Their forward voltage has a tolerance and varies with temperature. Connecting directly to a voltage source will cause the current to be uncontrolled, likely exceeding the maximum rating and destroying the LED. Always use a current-limiting mechanism (resistor or constant-current driver).

11. Practical Application Case Studies

Case Study 1: Linear LED Light Fixture. In a commercial troffer light, dozens of these LEDs are mounted on a long, narrow metal-core PCB (MCPCB). The MCPCB acts as both an electrical substrate and a heatsink. The LEDs are driven by a constant-current driver module. Careful selection from a tight color temperature bin ensures uniform white light across the entire fixture. The high efficacy of the LEDs allows the fixture to meet energy efficiency standards while providing ample illumination.

Case Study 2: Portable Device Status Indicator. A single LED is used as a battery charging/status indicator on a consumer electronics device. It is driven by a GPIO pin from a microcontroller through a small series resistor. The low power consumption of the LED minimizes drain on the battery. The small package size fits within the compact design of the device.

12. Operating Principle Introduction

An LED is a semiconductor p-n junction diode. When a forward voltage is applied, electrons from the n-type region and holes from the p-type region are injected into the junction region. When an electron recombines with a hole, it falls from a higher energy state in the conduction band to a lower energy state in the valence band. The energy difference is released in the form of a photon (light particle). The wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material used (e.g., Gallium Nitride for blue/green, Aluminum Gallium Indium Phosphide for red/amber). White LEDs are typically created by coating a blue LED chip with a yellow phosphor; some of the blue light is converted to yellow, and the mixture of blue and yellow light is perceived as white.

13. Technology Trends and Development

The LED industry continues to evolve with several clear trends. Efficacy (lumens per watt) is steadily increasing, reducing energy consumption for the same light output. Color quality is improving, with high-CRI LEDs becoming more common and affordable, enabling better color rendering in retail and residential settings. Miniaturization continues, allowing for higher pixel density in direct-view displays and more discreet lighting integration. There is also a trend towards smarter, connected lighting, with LEDs integrated with sensors and communication chips. Furthermore, research into novel materials like perovskites for color conversion and micro-LED technology for next-generation displays represents the cutting edge of solid-state lighting development.