LED Device Technical Specification - Revision 2 - Lifecycle: Permanent - Release Date: 2014-11-28 - Chinese Technical Document

1. Product Overview

This document provides comprehensive technical specifications and application guidelines for a specific LED device. The core information establishes the validity and revision status of the document. Its lifecycle phase is confirmed asRevision 2, indicating this is the second official revision of the device's technical data. The release date for this revision is2014-11-28 10:08:02. Crucial is that its expiration is marked aspermanent, which means the specifications contained in this revision are considered permanently valid and will not automatically expire due to planned obsolescence or the release date of a new revision. This permanence is a key characteristic for long-term design and manufacturing planning.

This device is designed to achieve high reliability and consistent performance. Its target markets include applications requiring stable, long-term light output, such as general lighting, indicator lights, display backlighting, and automotive interior lighting. Its core advantage lies in its fixed set of specifications, allowing engineers to confidently design systems, assured that the device's key parameters will not change unexpectedly in future production batches.

2. In-depth Technical Parameter Analysis

While the provided excerpt focuses on document metadata, a complete LED device technical datasheet would contain detailed objective parameters. The following section outlines the key data typically included and their significance.

2.1 Photometric and Color Characteristics

Photometric characteristics define the light output of an LED. Key parameters include:

• Luminous flux (Φ_v):Measured in lumens (lm), it represents the total perceived power of emitted light. Datasheets typically provide typical and minimum values at specified test currents (e.g., 20mA, 60mA) and junction temperature (T_j).
• Luminous intensity (I_v):Measured in millicandelas (mcd), it describes the luminous power per unit solid angle. Crucial for directional lighting applications. The viewing angle is specified together with this parameter (e.g., 120°).
• Dominant Wavelength (λ_D) or Correlated Color Temperature (CCT):For colored LEDs (red, green, blue, amber), the dominant wavelength defines the perceived color. For white LEDs, the Correlated Color Temperature (in Kelvin, K) specifies whether the light is warm white (e.g., 2700K), neutral white (e.g., 4000K), or cool white (e.g., 6500K).
• Color Rendering Index (CRI - R_a):For white light LEDs, CRI indicates the accuracy with which the light source reproduces the colors of objects compared to a natural light source. In applications where color discrimination is important, a higher CRI (closer to 100) is better.

2.2 Electrical Parameters

These parameters determine the electrical drive requirements and power consumption.

• Forward Voltage (V_F):The voltage drop across an LED when operating at a specified forward current (I_F). Typically given as a range (e.g., 2.8V to 3.4V at 20mA). This parameter is crucial for designing current-limiting circuits or selecting appropriate drivers.
• Forward Current (I_F):The recommended continuous operating current. Exceeding the maximum rated forward current can significantly shorten lifespan or cause immediate failure.
• Reverse Voltage (V_R):The maximum voltage that an LED can withstand when connected in reverse bias. Exceeding this voltage may cause irreversible damage.

2.3 Thermal Characteristics

LED performance and lifespan are highly dependent on temperature management.

• Junction temperature (T_j):is the temperature of the semiconductor chip itself. The maximum allowable T_j(e.g., 125°C) is a critical design limitation.
• Thermal resistance (R_θJA):Measured in °C/W, it indicates the efficiency of heat conduction from the LED junction to the ambient air. A lower value means better heat dissipation, which is crucial for maintaining light output and lifespan.
• Storage Temperature Range:Temperature range allowed for the device in a non-powered state.

3. Explanation of the Grading System

Due to manufacturing variations, LEDs are binned according to performance. This ensures that customers receive devices within specified tolerances.

• Wavelength/Color Temperature Binning:Grouping LEDs based on measured dominant wavelength or CCT. A bin code (e.g., "3A") corresponds to a specific wavelength range (e.g., 525-530nm).
• Luminous Flux Binning:LED are classified based on their light output under standard test conditions. This allows designers to select devices that meet the minimum brightness requirements for their applications.
• Forward Voltage Binning:By V_FRange classification helps design more uniform current distribution when multiple LEDs are connected in series.

4. Performance Curve Analysis

Graphical data provides deeper insights into device behavior under different conditions.

• I-V (Current-Voltage) Curve:This graph shows the relationship between forward current and forward voltage. It is nonlinear, which is a characteristic of diodes. This curve helps in understanding the dynamic resistance of an LED.
• Temperature Characteristics:The graph typically shows how luminous flux or forward voltage changes with increasing junction temperature. Luminous flux generally decreases as temperature rises.
• Relative Spectral Power Distribution:This graph shows the intensity of emitted light at each wavelength. It defines color characteristics and can reveal the presence of secondary peaks (e.g., in phosphor-converted white LEDs).

5. Mechanical and Packaging Information

Physical specifications are crucial for PCB design and assembly.

• Package dimensions:Detailed mechanical drawings specifying length, width, height, and any lens curvature. Always provide tolerances.
• Pad Layout (Package Outline):Recommended copper pad pattern on PCB for soldering. This includes pad size, shape, and spacing to ensure proper solder joint formation and provide mechanical stability.
• Polarity Marking:Mark clearly the anode (+) and cathode (-) terminals. Usually indicated by notches, cut corners, markings on the lens, or different pin lengths.

6. Soldering and Assembly Guide

Proper handling ensures reliability.

• Reflow soldering temperature profile:Time-temperature diagram specifying recommended preheat, soak, reflow, and cooling stages. Key parameters include peak temperature (typically up to 260°C for a few seconds) and time above liquidus.
• Operational precautions:关于ESD（静电放电）敏感性、湿度敏感等级（MSL）以及存储建议（如果MSL > 1，通常需存放在干燥柜中）的说明。
• Cleaning:Compatibility with common PCB cleaning solvents.

7. Packaging and Ordering Information

Information for procurement and logistics.

• Packaging Specifications:Describe carrier tape width, pocket size, reel diameter, and quantity per reel (e.g., 4000 pieces per 13-inch reel).
• Label:Explain the information printed on the reel label, including part number, quantity, date code, and bin code.
• Part number system:Decode the part number to indicate key attributes, such as color, brightness bin, voltage bin, and package type.

8. Application Suggestions

Guidance for effective implementation of the device.

• Typical application circuit:Schematic showing constant current drive circuit, series/parallel resistor calculation, and protective components such as transient voltage suppressors.
• Design considerations:Recommendations regarding thermal management (PCB copper area, heat dissipation), optical design (lens selection for desired beam pattern), and derating guidelines for high-temperature environments.
• Typical Use Cases:

  Based on its permanent revision status and common LED characteristics, this device is suitable for products requiring a long lifecycle or where design stability is critical. For example:

  • Industrial Control Panel:Status indicators on mechanical equipment that may operate for decades.
  • Infrastructure Lighting:Exit signs, emergency lighting, or architectural decorative lighting that are difficult to maintain and replace parts for.
  • Consumer appliances:Power indicator lights or control backlights on devices such as refrigerators or ovens.
  • Automotive interior lighting:Map lights, instrument panel backlighting, or switch illumination, where color and brightness consistency are crucial throughout the vehicle's service life.

  9. Technical Comparison and Differentiation

  The primary differentiating factors emphasized by the provided data are"Permanent" expiration period. The specifications of many electronic components are associated with specific revisions that may be updated frequently. The documentation for this device is declared to be permanently valid (Revision 2). This provides significant advantages:

  • Long-term supply guarantee:Manufacturers can stockpile or plan long-term production without worrying about specification changes.
  • Design Stability:Products designed around this device will not require revalidation or recertification due to specification changes.
  • Risk Reduction:Eliminates the risk that subtle performance variations between different revisions could affect the final product's quality or compliance.

  Compared to components with frequently updated specifications, this device prioritizes absolute consistency over potential incremental performance improvements.

  10. Frequently Asked Questions (Based on Technical Parameters)

  Q: What does "Lifecycle stage: Revised" mean?
  A: It indicates the stage of the document in its control process. "Revised" means this is an updated version (Revision 2) of a previously released specification, containing information that may have been corrected or enhanced.

  Q: The release date is 2014. Is this device obsolete?
  A: Not necessarily. "End of Life: Never" explicitly states the specification is permanently valid. The device may still be in active production. Its relevance depends on whether its technical parameters meet current application requirements.

  Q: How should I drive this LED?
  A: You must use a constant current source or a voltage source with a series current-limiting resistor. The specific circuit depends on the forward voltage (V_F) and forward current (I_F) specifications, which will be detailed in the full datasheet. Never connect an LED directly to a voltage source without current control.

  Q: Why is thermal management important for LEDs?
  A: High junction temperatures accelerate the degradation of semiconductor materials and phosphors (in white LEDs), leading to permanent reduction in light output (lumen depreciation) and potential color shift. It can also cause catastrophic failure. Proper heat dissipation is critical for performance and longevity.

  11. Practical Design and Usage Case Studies

  Scenario: Designing a Long-Life Industrial Status Indicator Panel.

  An engineer is designing a control panel for industrial equipment with an expected service life of 20 years. The panel requires red, green, and yellow status LEDs. Consistency and reliability are crucial.

  Reasons for Selection:The reasons the engineer selected this specific LED device (Revision 2, permanent) are as follows:

  1. Specification Guarantee:The permanently valid specification ensures that LEDs purchased for initial production and for spare parts/repair kits in the 15th year will have identical performance specifications, thereby maintaining panel consistency.
  2. Supply Chain Planning:The company can enter into long-term procurement agreements with distributors, confident that the component will not be "improved" in a way that necessitates a redesign.
  3. Design Implementation:Using detailed V_Fand I_Fdata, engineers designed a simple resistor-based drive circuit on the PCB for each color LED. Thermal resistance (R_θJA) Data is used to calculate the small amount of heat generated, which will be safely dissipated by the PCB copper, ensuring that the junction temperature remains well below the maximum rating even at an ambient temperature of 50°C for the device.
  4. Results:The final product benefits from stable, predictable indicator light performance throughout its entire service life, reducing warranty claims and maintenance complexity.

  12. Introduction to Working Principles

  LED (Light Emitting Diode) is a semiconductor device that emits light when an electric current passes through it. Its core principle isElectroluminescence.

  1. . Semiconductor chip ya ƙunshi p-n junction, inda p-type material (mai ramuka) ya hadu da n-type material (mai 'yan elektron masu 'yanci).
  2. Lokacin da aka yi amfani da ƙarfin lantarki mai kyau (positive terminal zuwa p-side, negative terminal zuwa n-side), 'yan elektron daga yankin n sun sami isasshen kuzari don ratsa junction, kuma su haɗu da ramukan yankin p.
  3. Wannan tsarin haɗuwa yana sakin kuzari. A cikin diode na yau da kullun, wannan kuzari yana fitowa a matsayin zafi. A cikin LED, zaɓaɓɓen kayan semiconductor (kamar Gallium Nitride don haske shuɗi/fari, ko Gallium Arsenide Phosphide don haske ja/rawaya) yana sa wannan kuzari ya fi fitowaPhoton(In the form of light particles) released.
  4. The wavelength (color) of the emitted light is determined by the bandgap of the semiconductor material. A larger bandgap produces higher-energy photons (shorter wavelength, such as blue light). White LEDs typically use a blue LED chip coated with yellow phosphor; some of the blue light is converted to yellow light, and the mixture is perceived as white light by the human eye.

  13. Teknoloji Trendleri ve Gelişimi

  LED endüstrisi, kalıcı ve sabit spesifikasyonlara sahip cihazların olgun ve istikrarlı bir teknoloji düğümünü temsil etmesine rağmen, gelişmeye devam etmektedir. Daha geniş pazarda gözlemlenebilen genel eğilimler şunları içerir:

  • Verimlilik Artışı (lm/W):Continuous improvements in internal quantum efficiency and light extraction techniques result in more lumens per watt of electrical input, thereby reducing energy consumption for the same light output.
  • Color Quality Improvement:The development of new phosphor systems for white LEDs has led to higher Color Rendering Index (CRI) values and more consistent correlated color temperatures across production bins.
  • Miniaturization:Package size continues to shrink (e.g., from 3528 to 2016 to 1010 metric code), enabling higher-density lighting arrays and integration into smaller devices.
  • Higher Power Density:The development of high-power LED packages capable of handling 1A, 3A, or higher currents typically necessitates complex active cooling solutions.
  • Intelligent and Connected Lighting:The direct integration of control electronics, sensors, and communication interfaces (such as Zigbee or Bluetooth) into LED modules represents an evolution from simple components toward intelligent lighting systems.

  With its permanent revision status, the device described in this document serves as a reliable, well-characterized building block within this evolving technological landscape, suitable for applications where proven stability is prioritized over the latest performance metrics.

  Detailed Explanation of LED Specification Terminology

  Complete Explanation of LED Technical Terminology

  I. Core Indicators of Photoelectric Performance

  Terminology	Unit/Representation	Popular Explanation	Why It Is Important
  Luminous Efficacy	lm/W (lumens per watt)	The luminous flux emitted per watt of electrical power; the higher the value, the more energy-efficient it is.	Directly determines the energy efficiency rating and electricity cost of the luminaire.
  Luminous Flux	lm (lumen)	The total amount of light emitted by a light source, commonly known as "brightness".	Determines whether a luminaire is bright enough.
  Viewing Angle	° (degrees), e.g., 120°	The angle at which light intensity drops to half, determining the beam width.	Affects the illumination range and uniformity.
  Correlated Color Temperature (CCT)	K (Kelvin), e.g., 2700K/6500K	The warmth or coolness of light color; lower values are yellowish/warm, higher values are whitish/cool.	Determining the lighting atmosphere and applicable scenarios.
  Color Rendering Index (CRI / Ra)	Unitless, 0–100	The ability of a light source to restore the true color of an object, Ra≥80 is recommended.	Affects color authenticity, used in high-demand places such as shopping malls and art galleries.
  SDCM (Standard Deviation of Color Matching)	MacAdam ellipse steps, e.g., "5-step"	A quantitative indicator of color consistency; a smaller step number indicates higher color consistency.	Ensure no color difference among the same batch of luminaires.
  Dominant Wavelength	nm (nanometer), misali 620nm (ja)	Rangi ya LED zenye rangi zinazolingana na thamani ya urefu wa wimbi.	Kuamua rangi ya LED moja kama nyekundu, manjano, kijani, n.k.
  Spectral Distribution	Wavelength vs. Intensity Curve	Display the intensity distribution of light emitted by the LED across various wavelengths.	Affects color rendering and color quality.

  II. Electrical Parameters

  Terminology	Symbol	Popular Explanation	Design Considerations
  Forward Voltage	Vf	The minimum voltage required to light up an LED, similar to a "starting threshold".	The driving power supply voltage must be ≥ Vf; voltages add up when multiple LEDs are connected in series.
  Forward Current	If	The current value that makes the LED emit light normally.	Constant current drive is often used, as the current determines brightness and lifespan.
  Matsakaicin ƙarfin bugun jini (Pulse Current)	Ifp	Peak current that can be withstood for a short period, used for dimming or flashing.	Pulse width and duty cycle must be strictly controlled to prevent overheating damage.
  Reverse Voltage	Vr	The maximum reverse voltage that an LED can withstand; exceeding it may cause breakdown.	The circuit must be protected against reverse polarity or voltage surges.
  Thermal Resistance	Rth (°C/W)	The resistance to heat flow from the chip to the solder joint. A lower value indicates better heat dissipation.	High thermal resistance requires a more robust thermal design; otherwise, the junction temperature will increase.
  ESD Immunity	V (HBM), e.g., 1000V	The higher the ESD immunity rating, the more resistant the device is to electrostatic damage.	Anti-static measures must be implemented during production, especially for high-sensitivity LEDs.

  III. Thermal Management and Reliability

  Terminology	Key Metrics	Popular Explanation	Impact
  Junction Temperature	Tj (°C)	The actual operating temperature inside the LED chip.	For every 10°C reduction, lifespan may double; excessively high temperatures cause lumen depreciation and color shift.
  Lumen Depreciation	L70 / L80 (hours)	The time required for brightness to drop to 70% or 80% of its initial value.	Directly defines the "service life" of an LED.
  Lumen Maintenance	% (e.g., 70%)	The percentage of remaining brightness after a period of use.	Characterizes the ability to maintain brightness after long-term use.
  Color Shift	Δu′v′ or MacAdam ellipse	The degree of color change during use.	Affects the color consistency of the lighting scene.
  Thermal Aging	Material performance degradation	Deterioration of packaging materials due to prolonged high temperatures.	May lead to decreased brightness, color shift, or open-circuit failure.

  IV. Packaging and Materials

  Terminology	Common Types	Popular Explanation	Characteristics and Applications
  Packaging Type	EMC, PPA, Ceramic	The housing material that protects the chip and provides optical and thermal interfaces.	EMC tahan panas baik, biaya rendah; keramik pendinginan unggul, umur panjang.
  Struktur chip	Face-up, Flip Chip	Chip electrode arrangement method.	Flip Chip offers better heat dissipation and higher luminous efficacy, suitable for high-power applications.
  Phosphor coating	YAG, silicate, nitride	Covered on the blue light chip, partially converted into yellow/red light, mixed into white light.	Different phosphors affect luminous efficacy, color temperature, and color rendering.
  Lens/Optical design	Plane, Microlens, Total Internal Reflection	Optical structure on the packaging surface, controlling light distribution.	Determine the beam angle and light distribution curve.

  V. Quality Control and Binning

  Terminology	Binning Content	Popular Explanation	Purpose
  Luminous Flux Classification	Codes such as 2G, 2H	Group by brightness level, each group has a minimum/maximum lumen value.	Ensure consistent brightness for the same batch of products.
  Voltage binning	Codes such as 6W, 6X	Group by forward voltage range.	Facilitates driver matching and improves system efficiency.
  Color binning.	5-step MacAdam ellipse	Group by color coordinates to ensure colors fall within a minimal range.	Ensure color consistency to avoid uneven color within the same luminaire.
  Color temperature binning	2700K, 3000K, etc.	Grouped by color temperature, each group has a corresponding coordinate range.	To meet the color temperature requirements of different scenarios.

  VI. Testing and Certification

  Terminology	Standards/Testing	Popular Explanation	Significance
  LM-80	Lumen Maintenance Test	Record brightness attenuation data under constant temperature conditions over a long period of illumination.	Used to estimate LED lifetime (combined with TM-21).
  TM-21	Standard for Lifetime Projection	Projecting lifetime under actual use conditions based on LM-80 data.	Provide scientific life prediction.
  IESNA Standard	Illuminating Engineering Society Standard	Covers optical, electrical, and thermal testing methods.	Industry-recognized testing basis.
  RoHS / REACH	Environmental Certification	Ensure products are free from hazardous substances (e.g., lead, mercury).	Market access requirements for entering international markets.
  ENERGY STAR / DLC	Energy Efficiency Certification	Energy Efficiency and Performance Certification for Lighting Products.	Commonly used in government procurement and subsidy programs to enhance market competitiveness.