LED Component Datasheet - Lifecycle Revision 2 - Technical Documentation

1. Product Overview

This technical datasheet pertains to a specific LED (Light Emitting Diode) component. The document's primary focus is on its lifecycle management and revision control, indicating a mature and stable product design. The repeated mention of "Revision: 2" and "Expired Period: Forever" suggests this is a finalized specification sheet for a component that has undergone at least one prior revision and is now considered a permanent reference. The target market for such a well-documented component includes industries requiring reliable, long-term sourcing for lighting solutions, such as general illumination, automotive lighting, signage, and consumer electronics. Its core advantage lies in its documented stability, providing engineers and procurement teams with confidence in part consistency and availability over extended product lifecycles.

2. Document Lifecycle and Revision Information

The provided content centers exclusively on the document's metadata. The lifecycle phase is explicitly stated as "Revision," and the revision number is "2." This signifies that the technical content of this datasheet has been updated from a previous version (Revision 1). The "Expired Period" is noted as "Forever," which implies this document version is intended to be a permanent, non-expiring reference for this specific product revision. The release date for Revision 2 is recorded as 2014-12-01. This historical date indicates the product specification was frozen at that time, and the component has been in production or available according to these parameters since then. Understanding this revision history is critical for traceability, especially when comparing performance or substituting components in existing designs.

3. Technical Parameters: In-Depth Objective Interpretation

While the explicit PDF snippet does not list numerical parameters, a standard LED datasheet for a component with a finalized revision would typically include the following sections. These are inferred based on standard industry practice for such documentation.

3.1 Photometric and Color Characteristics

This section would detail the light output and quality. Key parameters include Luminous Flux (measured in lumens, lm), which defines the perceived power of light. Luminous Intensity (measured in candelas, cd) might be specified for directional LEDs. The dominant Wavelength (for monochromatic LEDs) or Correlated Color Temperature (CCT, measured in Kelvin, K, for white LEDs) defines the color of the emitted light. For white LEDs, the Color Rendering Index (CRI, Ra) is a crucial metric indicating how naturally colors appear under the light source, with higher values (e.g., >80) being desirable for many applications.

3.2 Electrical Parameters

Electrical specifications are fundamental for circuit design. The Forward Voltage (Vf) is the voltage drop across the LED when operating at its rated current, typically ranging from 2.8V to 3.6V for common white LEDs. The Forward Current (If) is the recommended operating current (e.g., 20mA, 60mA, 150mA), directly influencing light output and lifespan. Reverse Voltage (Vr) specifies the maximum allowable voltage in the reverse direction before potential damage. Power Dissipation is calculated as Vf * If and must be managed thermally.

3.3 Thermal Characteristics

LED performance and longevity are highly temperature-dependent. The Junction-to-Ambient Thermal Resistance (RθJA) is a critical parameter, measured in °C/W, indicating how effectively heat is transferred from the LED chip (junction) to the surrounding environment. A lower value signifies better heat dissipation. The maximum Junction Temperature (Tj max) is the highest allowable temperature at the semiconductor chip itself, often around 125°C. Exceeding this limit drastically reduces lumen maintenance and can cause catastrophic failure.

4. Binning System Explanation

LED manufacturing yields natural variations. Binning is the process of sorting LEDs into groups (bins) based on key parameters to ensure consistency within a batch.

4.1 Wavelength / Color Temperature Binning

LEDs are binned according to their precise wavelength (for colored LEDs) or Correlated Color Temperature (for white LEDs). A typical white LED binning scheme might group LEDs within a 2-step or 3-step MacAdam ellipse on the chromaticity chart, ensuring minimal visible color difference between units. Common CCT bins include 2700K, 3000K (warm white), 4000K (neutral white), and 6500K (cool white).

4.2 Luminous Flux Binning

LEDs are also sorted by their light output at a specific test current. A bin code (e.g., flux bin) indicates the minimum and maximum luminous flux for that group. This allows designers to select bins that meet their minimum brightness requirements while managing cost, as higher-flux bins are typically more expensive.

4.3 Forward Voltage Binning

Sorting by forward voltage (Vf) helps in designing efficient driver circuits, especially when connecting multiple LEDs in series. Matching Vf bins ensures more uniform current distribution and brightness across an array, improving overall system performance and reliability.

5. Performance Curve Analysis

Graphical data provides deeper insight than tabular specifications alone.

5.1 Current vs. Voltage (I-V) Curve

This curve shows the nonlinear relationship between forward current and forward voltage. It is essential for selecting an appropriate current-limiting driver. The curve demonstrates the threshold voltage (where current begins to flow significantly) and the dynamic resistance in the operating region.

5.2 Temperature Characteristics

Key graphs include Luminous Flux vs. Junction Temperature, which typically shows output decreasing as temperature increases. Forward Voltage vs. Junction Temperature is also important, as Vf has a negative temperature coefficient (it decreases as temperature rises), which can affect constant-voltage drive schemes.

5.3 Spectral Power Distribution (SPD)

For white LEDs, the SPD graph shows the relative intensity of light across the visible spectrum. It reveals the peaks of the blue pump LED and the broader phosphor emission, providing visual confirmation of CCT and allowing for calculation of metrics like CRI and color gamut.

6. Mechanical and Packaging Information

Physical specifications ensure proper integration into the final product.

6.1 Dimension Drawing

A detailed mechanical drawing provides critical dimensions: package length, width, and height (e.g., 2.8mm x 3.5mm x 1.2mm for a 2835 package). It also shows lens shape, lead frame details, and any mounting features.

6.2 Pad Layout and Solder Pad Design

The recommended footprint for PCB (Printed Circuit Board) layout is provided, including pad dimensions, spacing (pitch), and shape. Adhering to this design is vital for reliable soldering and optimal thermal transfer from the LED's thermal pad (if present) to the PCB.

6.3 Polarity Identification

The datasheet clearly indicates the anode (+) and cathode (-) terminals. This is often shown via a diagram with a notch, a cut corner, a marking on the component, or different lead lengths. Correct polarity is mandatory for operation.

7. Soldering and Assembly Guidelines

Proper handling ensures reliability and prevents damage.

7.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow (peak temperature), and cooling rates. The maximum peak temperature (e.g., 260°C for a few seconds) and time above liquidus (TAL) are critical limits to avoid damaging the LED's epoxy lens or internal bonds.

7.2 Precautions and Handling

Guidelines include using ESD (Electrostatic Discharge) precautions, avoiding mechanical stress on the lens, not cleaning with certain solvents, and ensuring the soldering iron tip temperature is controlled during manual repair.

7.3 Storage Conditions

Recommended storage conditions to prevent moisture absorption (which can cause "popcorning" during reflow) and material degradation. This often involves storing in a dry environment (low humidity) at moderate temperatures and using moisture barrier bags for extended periods.

8. Packaging and Ordering Information

8.1 Packaging Specifications

Describes the packaging format, such as tape-and-reel dimensions (e.g., 8mm or 12mm tape width), reel quantity (e.g., 2000 or 4000 pieces per reel), and embossed carrier tape specifications. This information is necessary for automated pick-and-place assembly equipment.

8.2 Labeling Information

Explains the information printed on the reel label, which typically includes part number, quantity, lot/batch number, date code, and bin codes for flux and color.

8.3 Part Numbering Rule

Decodes the part number structure. A typical part number may include codes for package type, color temperature, luminous flux bin, forward voltage bin, and color rendering index (CRI). This allows precise ordering of the desired performance characteristics.

9. Application Recommendations

9.1 Typical Application Scenarios

Based on its inferred specifications (stable revision, common package), this LED is suitable for a wide range of applications requiring reliable, medium-power lighting. These include LED bulbs and tubes for residential/commercial lighting, backlighting for LCD displays and televisions, automotive interior lighting, architectural accent lighting, and general indicator lights.

9.2 Design Considerations

Key design factors include thermal management (using adequate PCB copper area or a heatsink), driver selection (constant current is strongly recommended over constant voltage), optical design (lenses or diffusers for desired beam pattern), and ensuring electrical parameters (Vf, If) are compatible with the chosen driver topology.

10. Technical Comparison and Differentiation

While a direct comparison requires a specific competitor part, the advantages of a component with a "Revision 2, Forever" lifecycle status are clear. It offers design stability, reducing the risk of future changes requiring circuit re-design. Long-term availability simplifies supply chain management for products with extended manufacturing lifetimes. The existence of a detailed, multi-revision datasheet itself indicates a commitment to product quality and customer support from the manufacturer.

11. Frequently Asked Questions (FAQs)

Q: What does "LifecyclePhase: Revision" mean?

A: It indicates the product's technical specifications have been updated from a previous version. This document (Revision 2) supersedes the earlier one.

Q: Why is the "Expired Period" listed as "Forever"?

A: This denotes that this specific revision of the datasheet is a permanent reference document. The specifications for Revision 2 are fixed and will not expire or be automatically replaced.

Q: How do I select the right bin codes when ordering?

A: Choose bins based on your application's requirements for color consistency (CCT/wavelength bin), minimum brightness (flux bin), and electrical matching for multi-LED designs (voltage bin). Consult the binning tables in the full datasheet.

Q: Can I drive this LED directly with a constant voltage source?

A: It is not recommended. LEDs are current-driven devices. A small change in forward voltage can cause a large change in current, potentially leading to overheating. Always use a constant-current driver or a current-limiting resistor with a stable voltage source.

12. Practical Use Case Examples

Case 1: Retrofit LED Tube Light: An engineer designs a T8 LED tube light. They select this LED based on its luminous flux bin to meet target lumens, its high CRI bin for quality light in an office, and its thermal characteristics to ensure longevity within the confined aluminum housing. The stable revision guarantees the second production run will perform identically to the first prototype.

Case 2: Automotive Dome Light: A designer uses this LED for interior dome lighting. The forward voltage binning allows them to connect three LEDs in series efficiently to match a 12V automotive electrical system with a simple linear current regulator. The robust datasheet with soldering profiles ensures the LEDs survive the high-temperature reflow process used for the vehicle's PCB assemblies.

13. Operating Principle Introduction

An LED is a semiconductor p-n junction diode. When a forward voltage is applied, electrons from the n-type material recombine with holes from the p-type material within the active region, releasing energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor materials used (e.g., InGaN for blue/UV, AlInGaP for red/amber). White LEDs are typically created by coating a blue or ultraviolet LED chip with a phosphor material. The phosphor absorbs some of the primary light and re-emits it at longer wavelengths (yellow, red), mixing with the remaining blue light to produce white light of a specific CCT.

14. Technology Trends and Developments

The LED industry continues to evolve. Trends include increasing luminous efficacy (more lumens per watt), improving color quality (higher CRI and R9 values for red rendition), and achieving higher reliability and longer lifetimes. Miniaturization of packages remains a trend, as does the development of novel phosphors for better spectral control and higher efficiency. Furthermore, smart lighting and human-centric lighting (HCL) are driving the integration of LEDs with sensors and controls to create dynamic, tunable white light systems that can adjust CCT and intensity throughout the day. The component described in this datasheet represents a mature, stable point in this ongoing technological progression.