1. Product Overview
This document details the specifications for a high-efficiency, green light-emitting diode (LED) designed for through-hole mounting on printed circuit boards (PCBs) or panels. The device utilizes an AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor material to produce green light, encapsulated in a 3.1mm diameter package with a water-clear lens. It is engineered for applications requiring reliable, low-power, and bright indicator lighting.
The core advantages of this LED include its compliance with RoHS (Restriction of Hazardous Substances) directives, indicating it is lead-free. It offers high luminous intensity output relative to its power consumption, making it an energy-efficient choice. The device is compatible with integrated circuits (ICs) due to its low current requirements, simplifying drive circuit design. Its versatile mounting capability and standardized through-hole package make it suitable for a wide range of electronic assembly processes.
The target market encompasses general-purpose electronics where visual status indication is required. This includes consumer electronics, office equipment, communication devices, industrial control panels, and household appliances. Its specifications make it ideal for applications where consistent brightness, color, and long-term reliability are important, but not for safety-critical or extreme environment applications without prior consultation.
2. In-Depth Technical Parameter Analysis
2.1 Absolute Maximum Ratings
These ratings define the stress limits beyond which permanent damage to the device may occur. Operation under or at these limits is not guaranteed.
- Power Dissipation (PD): 75 mW at an ambient temperature (TA) of 25°C. This is the maximum amount of power the LED can dissipate as heat without degradation.
- Forward Current:
- DC Forward Current (IF): 30 mA continuous.
- Peak Forward Current: 60 mA, permissible only under pulsed conditions with a 1/10 duty cycle and a pulse width of 0.1ms. This allows for brief over-driving to achieve higher instantaneous brightness, such as in strobe or multiplexing applications.
- Thermal Derating: The maximum allowable DC forward current must be linearly reduced by 0.4 mA for every degree Celsius the ambient temperature rises above 50°C. This is crucial for ensuring reliability at higher operating temperatures.
- Temperature Ranges:
- Operating: -40°C to +85°C.
- Storage: -55°C to +100°C.
- Lead Soldering Temperature: 260°C maximum for 5 seconds, measured at a point 2.0mm (0.0787\") from the LED body. This defines the process window for hand or wave soldering.
2.2 Electrical and Optical Characteristics
These parameters are measured at TA=25°C and define the typical performance of the device under normal operating conditions.
- Luminous Intensity (IV): Ranges from a minimum of 140 mcd to a typical 400 mcd, when driven at the standard test current (IF) of 20 mA. The intensity is measured using a sensor filtered to match the photopic (human eye) response curve (CIE). A ±15% tolerance applies to the guaranteed intensity value.
- Viewing Angle (2θ1/2): 40 degrees. This is the full angle at which the luminous intensity drops to half of its value measured on the central axis. A 40° angle indicates a relatively focused beam, suitable for directional indication.
- Wavelength Specifications:
- Peak Emission Wavelength (λP): 570 nm. This is the wavelength at which the spectral power output is maximum.
- Dominant Wavelength (λd): 572 nm. Derived from the CIE chromaticity diagram, this is the single wavelength perceived by the human eye that defines the color of the light. It is the key parameter for color consistency.
- Spectral Line Half-Width (Δλ): 11 nm. This indicates the spectral purity; a narrower width means a more saturated, pure green color.
- Forward Voltage (VF): Typically 2.4V, with a maximum of 2.4V at IF=20mA. The minimum is 2.1V. This parameter is critical for designing the current-limiting resistor in series with the LED.
- Reverse Current (IR): 100 μA maximum when a reverse voltage (VR) of 5V is applied. Important Note: The device is not designed for operation in reverse bias; this test condition is for characterization only. Applying reverse voltage in circuit can damage the LED.
3. Binning System Explanation
To manage natural variations in semiconductor manufacturing, LEDs are sorted into performance bins. This allows designers to select parts that meet specific intensity and color requirements.
3.1 Luminous Intensity Binning
Units: mcd @ 20mA. Each bin has a ±15% tolerance on its limits.
- GH Bin: 140 – 240 mcd
- JK Bin: 240 – 400 mcd
- LM Bin: 400 – 680 mcd
- NP Bin: 680 – 1150 mcd
The part number LTL1NHGK4K contains \"GH\" in its suffix, indicating it belongs to the GH intensity bin (140-240 mcd).
3.2 Dominant Wavelength Binning
Units: nm @ 20mA. Each bin has a ±1nm tolerance.
- H06: 566.0 – 568.0 nm
- H07: 568.0 – 570.0 nm
- H08: 570.0 – 572.0 nm
- H09: 572.0 – 574.0 nm
- H10: 574.0 – 576.0 nm
The part number contains \"K4K\\
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: better heat dissipation, higher efficacy, for high-power. |
| 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. | Ensures uniform brightness in same batch. |
| 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 | Ensures no harmful substances (lead, mercury). | Market access requirement internationally. |
| ENERGY STAR / DLC | Energy efficiency certification | Energy efficiency and performance certification for lighting. | Used in government procurement, subsidy programs, enhances competitiveness. |