Table of Contents
- 1. Product Overview
- 1.1 Core Advantages
- 1.2 Target Market and Applications
- 2. In-Depth Technical Parameter Analysis
- 2.1 Absolute Maximum Ratings
- 2.2 Electrical and Optical Characteristics
- 3. Binning System Specification
- 3.1 Luminous Intensity Binning
- 3.2 Dominant Wavelength Binning
- 4. Mechanical and Packaging Information
- 4.1 Outline Dimensions
- 4.2 Packaging Specification
- 5. Soldering and Assembly Guidelines
- 5.1 Storage and Cleaning
- 5.2 Lead Forming and PCB Assembly
- 5.3 Soldering Process
- 6. Application Design and Drive Method
- 6.1 Drive Circuit Design
- 6.2 Electrostatic Discharge (ESD) Protection
- 7. Performance Curves and Analysis
- 7.1 Forward Current vs. Forward Voltage (I-V Curve)
- 7.2 Luminous Intensity vs. Forward Current
- 7.3 Spectral Distribution
- 8. Technical Comparison and Design Considerations
- 8.1 Differentiation from Other Technologies
- 8.2 Thermal Management Considerations
- 8.3 Optical Design in Application
- 9. Frequently Asked Questions (Based on Technical Parameters)
- 9.1 Can I drive this LED without a series resistor?
- 9.2 Menene bambanci tsakanin Peak da Dominant Wavelength?
- 9.3 Aise nima akwai ±15% jurewa akan ƙarfin haske?
- 9.4 Zan iya amfani da wannan LED don aikace-aikacen waje?
- 10. Nazarin Aikin Zane na Aiki
- 10.1 Zanen Panel Nuna Matsayi
- 11. Operating Principle
- 12. Technology Trends
1. Product Overview
LTL816GE3T ni taa ya LED yenye rangi ya kijani iliyoundwa kwa kusanikishwa kwenye bodi za mzunguko (PCBs) kupitia mashimo. Ni sehemu ya familia maarufu ya kifurushi cha T-1, ikitoa umbo la kawaida linalolingana na matumizi mbalimbali yanayohitaji kiashiria cha hali au mwanga.
1.1 Core Advantages
LED hii inatoa faida kadhaa muhimu kwa wabunifu. Ina sifa ya matumizi ya nguvu ya chini na ufanisi mkubwa wa mwanga, na hivyo kufaa kwa matumizi yanayohitaji uhifadhi wa nishati. Kifaa hiki kimetengenezwa kwa kutumia vifaa visivyo na risasi na kinatii kikamilifu maagizo ya RoHS (Restriction of Hazardous Substances). Teknolojia yake ya semikondukta ya AlInGaP (Aluminum Indium Gallium Phosphide) ikichanganywa na lenzi ya kijani yenye uwazi hutoa mwanga wa kijani ulio wazi na mkali.
1.2 Target Market and Applications
The LTL816GE3T is designed for flexibility across multiple industries. Its primary applications include status indicators and backlighting in communication equipment, computers, consumer electronics, home appliances, and various industrial control systems. The standard T-1 package ensures easy integration into existing designs and manufacturing processes.
2. In-Depth Technical Parameter Analysis
Understanding the electrical and optical characteristics is crucial for reliable circuit design and performance prediction.
2.1 Absolute Maximum Ratings
These ratings define the limits beyond which permanent damage to the device may occur. They are specified at an ambient temperature (TA) of 25°C.
- Power Dissipation (Pd): 52 mW maximum. This is the total power the device can safely dissipate as heat.
- DC Forward Current (IF): 20 mA continuous. Exceeding this current can cause overheating and rapid degradation.
- Peak Forward Current: 60 mA maximum, but only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10 μs). This is useful for brief, high-intensity flashes.
- Derating: The maximum DC forward current must be linearly derated by 0.27 mA for every degree Celsius above 30°C. For example, at 85°C, the maximum allowable continuous current is significantly lower than 20 mA.
- Operating Temperature Range: -40°C to +85°C. The device is rated for operation in harsh environments.
- Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured at a distance of 1.6mm (0.063") from the LED body. This is critical for wave or hand soldering processes.
2.2 Electrical and Optical Characteristics
These are the typical performance parameters measured at TA=25°C and a forward current (IF) of 10 mA, unless otherwise stated.
- Luminous Intensity (Iv): Ranges from a minimum of 12.6 mcd to a typical value of 29 mcd, with a maximum of 110 mcd. The actual intensity is binned (see Section 4). The measurement uses a sensor/filter approximating the CIE photopic eye-response curve. A ±15% testing tolerance is applied to the guaranteed Iv value.
- Viewing Angle (2θ1/2): 35 degrees (typical). This is the full angle at which the luminous intensity drops to half of its axial (on-center) value. It defines the beam spread of the LED.
- Peak Emission Wavelength (λP): 568 nm (typical). This is the wavelength at the highest point in the emitted light spectrum.
- Dominant Wavelength (λd): Ranges from 563 nm to 573 nm (see Bin Table). This is derived from the CIE chromaticity diagram and represents the perceived color of the light.
- Spectral Line Half-Width (Δλ): 30 nm (typical). This indicates the spectral purity; a smaller value means a more monochromatic light.
- Forward Voltage (VF): 2.1V (minimum) to 2.6V (typical) at 10 mA. This is the voltage drop across the LED when operating.
- Reverse Current (IR): 10 μA maximum at a reverse voltage (VR) of 5V. Important: This device is not designed for reverse operation; this parameter is for test purposes only.
3. Binning System Specification
To ensure color and brightness consistency in production, LEDs are sorted into bins. The LTL816GE3T uses a two-dimensional binning system.
3.1 Luminous Intensity Binning
LEDs are classified based on their measured luminous intensity at 10 mA. The bin codes and their ranges are as follows (tolerance on each bin limit is ±15%):
- O1: 60.0 - 110 mcd
- N1: 40.0 - 60.0 mcd
- N2: 29.0 - 40.0 mcd
- N3: 19.0 - 29.0 mcd
- N4: 12.6 - 19.0 mcd
The Iv classification code is marked on each packing bag for traceability.
3.2 Dominant Wavelength Binning
LEDs are also sorted by their dominant wavelength to control the precise shade of green. The bin codes and ranges are as follows (tolerance on each bin limit is ±1 nm):
- YG: 571.0 - 573.0 nm
- PG: 569.0 - 571.0 nm
- GG: 567.0 - 569.0 nm
- GG1: 565.0 - 567.0 nm
- GG2: 563.0 - 565.0 nm
4. Mechanical and Packaging Information
4.1 Outline Dimensions
The LED conforms to the standard T-1 (3mm) radial leaded package. Key dimensional notes include:
- All dimensions are in millimeters (inches provided in the original drawing).
- Matsakaicin jurewar ±0.25mm (.010") ya shafi sai dai idan an ƙayyade akasin haka.
- Resin ɗin da ke ƙarƙashin flange na iya fitowa har zuwa 1.0mm (.04") matsakaici.
- Lead spacing is measured where the leads emerge from the package body.
- The anode (positive) lead is typically the longer lead, which is a common industry practice for polarity identification.
4.2 Packaging Specification
The LEDs are packaged for automated handling and bulk shipping:
- Basic Unit: 500, 200, or 100 pieces per anti-static packing bag.
- Inner Carton: Contains 10 packing bags, totaling 5,000 pieces (when using 500pc bags).
- Outer Carton: Contains 8 inner cartons, totaling 40,000 pieces per outer carton.
- A note specifies that in every shipping lot, only the final pack may not be a full pack.
5. Soldering and Assembly Guidelines
Proper handling is essential to prevent damage and ensure long-term reliability.
5.1 Storage and Cleaning
LEDs anaɗe a cikin yanayin da bai wuce 30°C da zafi na 70% ba. Idan an cire su daga marufi na asali, ya kamata a yi amfani da su cikin watanni uku. Don ajiya mai tsawo, yi amfani da akwati mai rufi tare da desiccant ko yanayin nitrogen. Tsaftacewa, idan ya cancanta, ya kamata a yi ta hanyar amfani da kaushi na barasa kamar isopropyl alcohol.
5.2 Lead Forming and PCB Assembly
Dole ne a lanƙwasa igiyoyin a wani wuri aƙalla 3mm daga gindin ruwan tabarau na LED. Kada a yi amfani da gindin firam ɗin jagora a matsayin fulcrum. Duk wani siffantawa dole ne a yi shi a cikin zafin daki kuma before soldering. During PCB insertion, use the minimum clinch force necessary to avoid mechanical stress on the package.
5.3 Soldering Process
A minimum clearance of 1.6mm must be maintained from the base of the lens to the solder point. Dipping the lens into solder must be avoided. Do not apply stress to the leads during soldering while the LED is hot.
Recommended Soldering Conditions:
- Soldering Iron: Temperature 350°C max. Time: 3 seconds max (one time only). Position: No closer than 1.6mm from the lens base.
- Wave Soldering: Pre-heat: 100°C max for 60 seconds max. Solder Wave: 260°C max. Soldering Time: 5 seconds max. Dipping Position: No lower than 1.6mm from the lens base.
Critical Warning: Excessive temperature or time can deform the lens or cause catastrophic failure. Infrared (IR) reflow soldering is not suitable for this through-hole type LED product.
6. Application Design and Drive Method
6.1 Drive Circuit Design
LED ni abin da ake sarrafa halin yanzu. Don tabbatar da daidaiton haske lokacin da ake amfani da LED da yawa a layi daya, ana ba da shawarar sosai don amfani da resistor mai iyakance halin yanzu a jere tare da kowane LED na musamman (Circuit A). Wannan yana rama ƙananan bambance-bambance a cikin halayen ƙarfin gaba (Vf) tsakanin LED na musamman. Amfani da resistor guda ɗaya don LED da yawa a layi daya (Circuit B) ba a ba da shawara ba, saboda bambance-bambance a cikin Vf zai haifar da babban bambancin haske tsakanin LED.
6.2 Electrostatic Discharge (ESD) Protection
Static electricity can damage the semiconductor junction. To prevent ESD damage:
- Operators should use conductive wrist straps or anti-static gloves.
- All equipment, worktables, and storage racks must be properly grounded.
- Use an ion blower to neutralize static charge that may build up on the plastic lens surface due to friction.
- Ensure personnel working in static-safe areas are properly trained and ESD-certified.
7. Performance Curves and Analysis
The datasheet references typical characteristic curves which are essential for detailed design analysis. These curves graphically represent the relationship between key parameters under varying conditions.
7.1 Forward Current vs. Forward Voltage (I-V Curve)
Wannan madaidaiciyar tana nuna alaƙar da ba ta da layi tsakanin igiyar ruwa da ke gudana ta cikin LED da ƙarfin lantarki a kanta. Yana da mahimmanci don zaɓar daidaitaccen ƙimar resistor na jerin don cimma ingantaccen igiyar aiki daga wani ƙarfin wutar lantarki. Madaidaiciyar za ta nuna madaidaicin ƙarfin lantarki na "gwiwa" kusan 2V, bayan haka igiyar ruwa tana ƙaruwa da sauri tare da ƙaramin ƙaruwar ƙarfin lantarki.
7.2 Luminous Intensity vs. Forward Current
This curve demonstrates how light output increases with drive current. It is generally linear over a range but will saturate at higher currents due to thermal effects and efficiency droop. This helps designers balance brightness requirements against power consumption and heat generation.
7.3 Spectral Distribution
Taswirar rarraba bakan tana nuna ƙarfin haske da aka fitar a cikin tsayin daban-daban. Ga wannan koren AlInGaP LED, yawanci zai nuna ƙulli mai kunkuntar da ke tsakiya a kusan 568 nm (tsayin kololuwa) tare da rabin faɗin halayen kusan 30 nm, yana ayyana tsaftar launi.
8. Technical Comparison and Design Considerations
8.1 Differentiation from Other Technologies
The use of AlInGaP technology for green light offers advantages over older technologies like Gallium Phosphide (GaP). AlInGaP LEDs generally provide higher luminous efficiency and better temperature stability, resulting in brighter and more consistent light output over the operating temperature range.
8.2 Thermal Management Considerations
While the power dissipation is low (52mW max), the derating specification is critical. In high ambient temperature applications or when driving at the maximum continuous current, the effective current limit decreases. Designers must calculate the actual junction temperature based on ambient temperature, forward current, and the thermal resistance path through the leads to the PCB to ensure reliable operation.
8.3 Optical Design in Application
The 35-degree viewing angle provides a reasonably wide beam, suitable for status indicators that need to be visible from various angles. For applications requiring a more focused or diffused beam, secondary optics (lenses or light pipes) can be used in conjunction with the LED. The green transparent lens offers good color saturation.
9. Frequently Asked Questions (Based on Technical Parameters)
9.1 Can I drive this LED without a series resistor?
No. The forward voltage has a range (2.1V to 2.6V) and is temperature-dependent. Connecting it directly to a voltage source even slightly above its Vf can cause an uncontrolled surge in current, exceeding the absolute maximum rating and destroying the device. A series resistor is mandatory for current regulation.
9.2 Menene bambanci tsakanin Peak da Dominant Wavelength?
Peak Wavelength (λP) shine tsayin raƙuman da yake a mafi girman matsayi a cikin bakan fitarwa. Dominant Wavelength (λd) It is a calculated value from colorimetry that represents the perceived color. For a monochromatic source like this green LED, they are often close, but λd is the more relevant parameter for color specification in applications.
9.3 Aise nima akwai ±15% jurewa akan ƙarfin haske?
This tolerance accounts for measurement system variations and minor production variances. The binning system (N1, N2, etc.) is used to provide guaranteed minimum and maximum intensity ranges for production consistency. Designers should use the minimum value from the selected bin for worst-case brightness calculations.
9.4 Zan iya amfani da wannan LED don aikace-aikacen waje?
The datasheet states it is suitable for indoor and outdoor signs. The operating temperature range of -40°C to +85°C supports outdoor use. However, for long-term outdoor exposure, additional design considerations are needed, such as protection from UV radiation (which can degrade the epoxy lens over time) and moisture ingress, which are not covered in this component-level datasheet.
10. Nazarin Aikin Zane na Aiki
10.1 Zanen Panel Nuna Matsayi
Consider a control panel requiring ten green status indicators. The system power supply is 5V DC. The goal is to achieve a bright, uniform indication.
- Current Selection: Choose a drive current of 10 mA, which is within the 20 mA maximum and provides good brightness (typ. 29 mcd).
- Resistor Calculation: Using the typical Vf of 2.6V at 10 mA. Resistor value R = (Vsupply - Vf) / If = (5V - 2.6V) / 0.01A = 240 Ω. Use the nearest standard value (240 Ω or 220 Ω). Power rating: P = I^2 * R = (0.01)^2 * 240 = 0.024W, so a standard 1/8W or 1/10W resistor is sufficient.
- Circuit Topology: Implement Circuit A from the datasheet: one independent current-limiting resistor for each of the ten LEDs, all connected in parallel to the 5V rail. This ensures uniform brightness even if the Vf of individual LEDs varies within the bin.
- PCB Layout: Maintain the 1.6mm solder clearance. Ensure the anode (longer lead) is correctly oriented on the PCB silkscreen. Provide adequate copper pour for heat dissipation if operating in a high ambient temperature.
- Binning: Specify a tight intensity bin (e.g., N2 or N1) and a specific dominant wavelength bin (e.g., PG) in the purchase order to ensure visual consistency across all ten indicators on the panel.
11. Operating Principle
The LTL816GE3T operates on the principle of electroluminescence in a semiconductor p-n junction. When a forward voltage exceeding the junction's built-in potential is applied, electrons from the n-type AlInGaP semiconductor layer are injected across the junction into the p-type layer, and holes are injected in the opposite direction. These charge carriers recombine in the active region near the junction. A portion of the energy released during this recombination process is emitted as photons (light). The specific composition of the AlInGaP semiconductor alloy determines the bandgap energy, which directly defines the wavelength (color) of the emitted light—in this case, green. The transparent epoxy lens serves to protect the semiconductor chip, shape the light output beam, and enhance light extraction efficiency.
12. Technology Trends
Through-hole LEDs like the T-1 package remain widely used due to their simplicity, robustness, and ease of manual assembly or repair. However, the broader industry trend is towards surface-mount device (SMD) packages for automated assembly, higher density, and better thermal performance. For indicator applications, smaller SMD packages (e.g., 0603, 0402) are increasingly common. In terms of materials, AlInGaP technology for red, orange, and yellow/green LEDs is mature and offers high efficiency. For true green and blue, InGaN (Indium Gallium Nitride) is the dominant technology. Future developments in through-hole indicator LEDs may focus on further increasing efficiency (lumens per watt) and improving color consistency and stability over temperature and lifetime, though major architectural shifts are more likely in high-power and lighting-grade SMD packages.
LED Specification Terminology
Complete explanation of LED technical terms
Photoelectric Performance
| Term | Unit/Representation | Simple Explanation | Why Important |
|---|---|---|---|
| Luminous Efficacy | lm/W (lumens per watt) | Light output per watt of electricity, higher means more energy efficient. | Directly determines energy efficiency grade and electricity cost. |
| Luminous Flux | lm (lumens) | Total light emitted by source, commonly called "brightness". | Determines if the light is bright enough. |
| Viewing Angle | ° (degrees), e.g., 120° | Angle where light intensity drops to half, determines beam width. | Affects illumination range and uniformity. |
| CCT (Color Temperature) | K (Kelvin), e.g., 2700K/6500K | Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool. | Determines lighting atmosphere and suitable scenarios. |
| CRI / Ra | Unitless, 0–100 | Ability to render object colors accurately, Ra≥80 is good. | Affects color authenticity, used in high-demand places like malls, museums. |
| SDCM | MacAdam ellipse steps, e.g., "5-step" | Color consistency metric, smaller steps mean more consistent color. | Ensures uniform color across same batch of LEDs. |
| Dominant Wavelength | nm (nanometers), e.g., 620nm (red) | Wavelength corresponding to color of colored LEDs. | Determines hue of red, yellow, green monochrome LEDs. |
| Spectral Distribution | Wavelength vs intensity curve | Shows intensity distribution across wavelengths. | Affects color rendering and quality. |
Electrical Parameters
| Term | Symbol | Simple Explanation | Design Considerations |
|---|---|---|---|
| Forward Voltage | Vf | Minimum voltage to turn on LED, like "starting threshold". | Driver voltage must be ≥Vf, voltages add up for series LEDs. |
| Forward Current | If | Current value for normal LED operation. | Usually constant current drive, current determines brightness & lifespan. |
| Max Pulse Current | Ifp | Peak current tolerable for short periods, used for dimming or flashing. | Pulse width & duty cycle must be strictly controlled to avoid damage. |
| Reverse Voltage | Vr | Max reverse voltage LED can withstand, beyond may cause breakdown. | Circuit must prevent reverse connection or voltage spikes. |
| Thermal Resistance | Rth (°C/W) | Resistance to heat transfer from chip to solder, lower is better. | High thermal resistance requires stronger heat dissipation. |
| ESD Immunity | V (HBM), e.g., 1000V | Ability to withstand electrostatic discharge, higher means less vulnerable. | Anti-static measures needed in production, especially for sensitive LEDs. |
Thermal Management & Reliability
| Term | Key Metric | Simple Explanation | Impact |
|---|---|---|---|
| Junction Temperature | Tj (°C) | Actual operating temperature inside LED chip. | Every 10°C reduction may double lifespan; too high causes light decay, color shift. |
| Lumen Depreciation | L70 / L80 (hours) | Time for brightness to drop to 70% or 80% of initial. | Directly defines LED "service life". |
| Lumen Maintenance | % (e.g., 70%) | Percentage of brightness retained after time. | Indicates brightness retention over long-term use. |
| Color Shift | Δu′v′ or MacAdam ellipse | Degree of color change during use. | Affects color consistency in lighting scenes. |
| Thermal Aging | Material degradation | Deterioration due to long-term high temperature. | May cause brightness drop, color change, or open-circuit failure. |
Packaging & Materials
| Term | Common Types | Simple Explanation | Features & Applications |
|---|---|---|---|
| Package Type | EMC, PPA, Ceramic | Housing material protecting chip, providing optical/thermal interface. | EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life. |
| Chip Structure | Front, Flip Chip | Chip electrode arrangement. | Flip chip: kona mafuta bora, ufanisi wa juu, kwa nguvu kubwa. |
| Phosphor Coating | YAG, Silicate, Nitride | Covers blue chip, converts some to yellow/red, mixes to white. | Different phosphors affect efficacy, CCT, and CRI. |
| Lens/Optics | Flat, Microlens, TIR | Optical structure on surface controlling light distribution. | Determines viewing angle and light distribution curve. |
Quality Control & Binning
| Term | Binning Content | Simple Explanation | Purpose |
|---|---|---|---|
| Luminous Flux Bin | Code e.g., 2G, 2H | Grouped by brightness, each group has min/max lumen values. | E kia mau tonu te marama i roto i te pūhui kotahi. |
| Voltage Bin | Code e.g., 6W, 6X | Grouped by forward voltage range. | Facilitates driver matching, improves system efficiency. |
| Color Bin | 5-step MacAdam ellipse | Grouped by color coordinates, ensuring tight range. | Guarantees color consistency, avoids uneven color within fixture. |
| CCT Bin | 2700K, 3000K etc. | Grouped by CCT, each has corresponding coordinate range. | Meets different scene CCT requirements. |
Testing & Certification
| Term | Standard/Test | Simple Explanation | Significance |
|---|---|---|---|
| LM-80 | Lumen maintenance test | Long-term lighting at constant temperature, recording brightness decay. | Used to estimate LED life (with TM-21). |
| TM-21 | Life estimation standard | Estimates life under actual conditions based on LM-80 data. | Provides scientific life prediction. |
| IESNA | Illuminating Engineering Society | Covers optical, electrical, thermal test methods. | Industry-recognized test basis. |
| RoHS / REACH | Environmental certification | Yana tabbatar da babu abubuwa masu cutarwa (gubar, mercury). | Bukatar shiga kasuwa a duniya. |
| ENERGY STAR / DLC | Ilimin ingancin makamashi | Ilimin ingancin makamashi da aiki don hasken wuta. | Used in government procurement, subsidy programs, enhances competitiveness. |