LTL1CHKGTLC 3.1mm Through-Hole Green LED Datasheet - 2.4V Forward Voltage - 75mW Power Dissipation - Technical Documentation

1. Product Overview

This document details the technical specifications of a high-efficiency green through-hole light-emitting diode. This device is specifically designed for general indicator applications, suitable for scenarios requiring reliability, low power consumption, and high luminous intensity. Its primary target markets include consumer electronics, industrial control panels, communication equipment, and various household appliances requiring status indication.

The core advantage of this LED component lies in its compliance with lead-free and RoHS environmental standards, enabling high luminous intensity output within a compact 3.1mm diameter package. It features low power consumption, and due to its low current requirement, it offers good compatibility with integrated circuits, making it highly suitable for modern electronic design.

2. In-depth Interpretation of Technical Parameters

2.1 Absolute Maximum Ratings

These ratings define the stress limits of the device. Exceeding these limits may cause permanent damage. Operation at or beyond these limits is not recommended.

• Power Dissipation (Pd):75 mW. This is the maximum power that the LED can dissipate as heat when the ambient temperature (T_A) is 25°C.
• DC Forward Current (I_F):30 mA. Maximum continuous forward current for the LED.
• Peak Forward Current:60 mA. This current is only permissible under pulse conditions (1/10 duty cycle, 0.1ms pulse width) to briefly achieve higher light output without overheating.
• Reverse Voltage (V_R):5 V. Exceeding this voltage under reverse bias may cause immediate junction breakdown.
• Operating temperature range:-40°C to +100°C. This is the ambient temperature range within which the LED is designed to operate normally.
• Pin soldering temperature:260°C for 5 seconds, measured at a point 2.0mm from the LED body. This defines the thermal profile requirement for hand or wave soldering.

2.2 Electrical/Optical Characteristics

These are at T_A=25°C-ko nini a caca performance parameter, nini a define device normal operation behavior.

• Luminous intensity (I_V):Test current (I_F) 2mA-ko, 18 to 52 mcd (minimum to maximum). Nini a wide range binning system-ko manage (Section 3 see). Intensity measurement filtered sensor match human eye photopic response (CIE curve) use perform.
• Forward voltage (V_F):A cikin I_F= 2mA, ƙimar al'ada ita ce 2.1V zuwa 2.4V. Wannan siga yana da mahimmanci don ƙirƙirar resistor mai iyakancewar kwarara a cikin da'irar tuƙi.
• Kallon kusurwa (2θ_1/2):45 degrees. This is the full angle at which the luminous intensity drops to half of the axial measured value. The 45° angle provides a fairly wide viewing cone.
• Peak Emission Wavelength (λ_P):575 nm. This is the wavelength at which the spectral power output is highest.
• Dominant Wavelength (λ_d):572 nm. This value is derived from the CIE chromaticity diagram and represents the perceived color of the light, which is a pure green.
• Spectral line half-width (Δλ):11 nm. This indicates spectral purity; the narrower the width, the more saturated and pure the color.
• Reverse current (I_R):At V_R= 5V, maximum 100 µA.
• Capacitance (C):Typical value is 40 pF at zero bias and 1MHz frequency, relevant to high-frequency switching applications.

3. Grading System Description

To ensure consistent brightness and color for end users, LEDs are sorted into different bins based on measured performance.

3.1 Luminous Intensity Binning

The unit is millicandela (mcd), measured at 2 mA. The tolerance for each grade limit is ±15%.

• Grade 3Y:18 mcd (min) to 23 mcd (max)
• Gear 3Z:23 mcd to 30 mcd
• Gear A:30 mcd to 38 mcd
• Gear B:38 mcd to 52 mcd

Gear code is marked on the packaging bag, allowing designers to select LEDs with a specific brightness range for their application.

3.2 Dominant Wavelength Binning

The unit is nanometers (nm), measured at 2 mA. The tolerance for each bin limit is ±1 nm. This ensures strict control over the perceived green color.

• Gear H06:566.0 nm to 568.0 nm
• Gear H07:568.0 nm to 570.0 nm
• Gear H08:570.0 nm to 572.0 nm
• Gear H09:572.0 nm to 574.0 nm
• Gear H10:574.0 nm to 576.0 nm
• Gear H11:576.0 nm to 578.0 nm

4. Performance Curve Analysis

The datasheet references typical characteristic curves, which are crucial for understanding device behavior under non-standard conditions. Although specific graphs are not reproduced in the text, their meaning is analyzed as follows.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

The I-V characteristic is nonlinear. For an AlInGaP LED like this, the forward voltage exhibits a negative temperature coefficient. This means that as the junction temperature increases, the forward voltage required to achieve the same current slightly decreases. This characteristic is important for constant current drive design to ensure stable light output.

4.2 Luminous Intensity vs. Forward Current

Within the typical operating range, the light output (luminous intensity) is approximately proportional to the forward current. However, at extremely high currents, efficiency may decrease due to increased heat generation (efficiency droop effect). Operating at or below the recommended DC current ensures optimal efficiency and lifetime.

4.3 Luminous Intensity vs. Ambient Temperature

The light output of an LED decreases as its junction temperature rises. This thermal quenching effect is particularly significant for AlInGaP materials. Designers must consider thermal management, especially in high ambient temperature environments or when driving LEDs with high currents, to maintain consistent brightness.

4.4 Spectral Distribution

The reference spectral plot will show a peak at approximately 575 nm with a typical FWHM of 11 nm. The dominant wavelength of 572 nm defines the perceived green color point on the CIE chart.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This device employs a standard 3.1mm diameter circular through-hole package. Key dimensional specifications include:

• All dimensions are in millimeters (inches in parentheses).
• Unless otherwise specified, the standard tolerance is ±0.25mm.
• The maximum resin protrusion under the flange is 1.0mm.
• Pin pitch is measured at the point where the pins extend from the package body, which is crucial for PCB layout.

5.2 Polarity Identification

For through-hole LEDs, the cathode is typically identified by a flat edge on the lens rim or a shorter lead. The datasheet implies standard industry practice; the longer lead is the anode (+), and the shorter lead is the cathode (-). Correct polarity must be observed during assembly.

6. Welding and Assembly Guide

Proper handling is crucial to prevent damage and ensure reliability.

6.1 Storage Conditions

LEDs should be stored in an environment where the temperature does not exceed 30°C and the relative humidity does not exceed 70%. If removed from the original moisture-proof bag, they should be used within three months. For storage outside the original packaging for longer periods, use a sealed container with desiccant or a nitrogen environment.

6.2 Lead Forming

• Bending must be performed at a location at least 3mm away from the base of the LED lens.
• Do not use the root of the lead frame as a fulcrum.
• Pin forming must be performed at room temperature, and在completed before the soldering process.
• When inserting into the PCB, apply minimal pressing force to avoid mechanical stress on the package.

6.3 Soldering Process

• Maintain a minimum distance of 2mm from the lens root to the solder joint. Do not immerse the lens in solder.
• Avoid applying external stress to the pins when the LED is heated due to soldering.
• Recommended soldering conditions:
  • Manual soldering (soldering iron):Maximum temperature 300°C, maximum soldering time per pin 3 seconds (only once).
  • Wave soldering:Maximum preheat temperature 100°C, maximum 60 seconds. Maximum solder wave temperature 260°C, maximum 5 seconds.
• Excessive temperature or time may cause lens deformation or catastrophic failure.

6.4 Cleaning

If cleaning is required, use only alcohol-based solvents, such as isopropanol. Harsh chemicals may damage the lens material.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The standard packaging process is as follows:

• LED suna cikin jakar 1000, 500, ko 250 na kowane.
• Jakoki goma (10) ana saka su cikin akwati na ciki (Jimlar 10,000).
• Akwatuna na ciki takwas (8) ana saka su cikin akwatin jigilar waje (Jimlar 80,000).
• Within a single shipment lot, only the final packaging may contain a non-full quantity.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is suitable for a wide range of indicator light applications, including but not limited to:

• Power status indicators on consumer electronics (TVs, audio equipment, chargers).
• Signal and status lights on network routers, modems, and communication equipment.
• Panel indicator lights on industrial control systems, test equipment, and instrumentation.
• Backlighting for switches, buttons, and indicators in household appliances.

Important Notice:The datasheet clearly states that this LED is suitable for general electronic equipment. For applications requiring extremely high reliability, especially where failure could endanger life or health (aviation, medical, traffic safety), prior consultation with the manufacturer is required.

8.2 Drive Circuit Design

LED is a current-driven device. To ensure uniform brightness when using multiple LEDs,Strongly recommendedConnect a current-limiting resistor in series with each LED (Circuit Model A).

• Circuit Model A (Recommended):Each LED has its own series resistor connected to the power supply. This compensates for the natural differences in forward voltage (V_F) between different LEDs, ensuring each LED receives the same current and thus has similar brightness.
• Circuit Model B (Not Recommended):Multiple LEDs in parallel share one resistor. Due to differences in V_F, the current is not evenly distributed, resulting in significant brightness differences among the LEDs.

The resistor value (R) is calculated using Ohm's Law: R = (V_{Power supply}- V_F) / I_F. Use the maximum V from the datasheet_FConservative design using a value (2.4V) to ensure the current does not exceed the required I_F.

。

8.3 Electrostatic Discharge (ESD) Protection

LEDs are sensitive to electrostatic discharge. ESD damage may manifest as high reverse leakage current, low forward voltage, or failure to illuminate at low current.

• Matakan rigakafi:
• Ma'aikatan ya kamata su sanya bandeji na wuyan hannu mai ɗaukar wutar lantarki ko safar hannu na hana tashin hankali.
• All equipment, workstations, and storage racks must be properly grounded.

Use an ionizer to neutralize static charges that may accumulate on plastic lenses.ESD verification test:_FTo check a suspicious LED, measure its forward voltage at a very low current (e.g., 0.1mA). A "good" AlInGaP LED under this test condition has a V

Should be greater than 1.4V.

9. Technical Comparison and Differentiation

• This AlInGaP-based green LED offers specific advantages:Compared to traditional GaP green LEDs:
• AlInGaP technology provides significantly higher luminous efficiency, as well as a more saturated and purer green color (dominant wavelength approximately 572nm) compared to the yellowish-green of older GaP LEDs.Compared to InGaN green LEDs:
• While InGaN LEDs can achieve very high brightness, AlInGaP LEDs typically offer superior performance in the amber to red spectrum and within specific green wavelength ranges, potentially featuring lower forward voltage and excellent stability.Key Differentiating Factors:

The combination of a 3.1mm package, a well-defined 45° viewing angle, a comprehensive binning system covering intensity and wavelength, and clear application considerations makes it a reliable and predictable choice for standard indicator light use.

10. Frequently Asked Questions (Based on Technical Specifications)

10.1 Can I drive this LED directly with a 5V power supply without a resistor?A'a, hakan zai lalata LED.

LED has very low dynamic resistance when forward biased. Connecting it directly to a voltage source such as 5V will cause excessive current to flow, far exceeding the absolute maximum rating of 30mA DC, leading to immediate overheating and failure. When using a voltage source, a current-limiting resistor in series is always required.

10.2 Me yasa kewayon ƙarfin haske yake da faɗi haka (18-52 mcd)?

Wannan kewayon yana wakiltar jimlar faɗin rarraba samarwa. Ana rarraba LED ɗaya zuwa takamaiman "bin" (3Y, 3Z, A, B) tare da mafi ƙarancin kewayon. Ta hanyar ƙayyadaddun lambar bin da ake buƙata lokacin yin oda, masu ƙira za su iya tabbatar da daidaiton haske a cikin dukkan raka'o'in rukunin samarwarsu.

10.3 Menene bambanci tsakanin madaidaicin tsawon raƙuman ruwa da babban tsawon raƙuman ruwa?_PMadaidaicin tsawon raƙuman ruwa (λ):
The physical wavelength at which an LED emits the maximum optical power. It is the peak point on the spectral output graph._dDominant Wavelength (λ):_dA calculated value based on human color perception (CIE chart). It is the wavelength of a pure monochromatic light that appears identical in color to the LED's output. λ

It is more relevant for describing perceived color, which is why it is used for grading.

10.4 How do I select the appropriate current for my application?_dThe test condition is 2mA, which is a common low-current rating for indicator LEDs. For standard indication brightness, operation typically ranges from 2mA to 10mA. For higher brightness, it can approach the maximum DC rating of 20mA, but the increased power dissipation (P_F= V_F* I

), to ensure it remains below 75mW, especially at higher ambient temperatures. Always refer to the derating curve (linear decrease of 0.4mA per °C starting from 50°C).

11. Practical Design and Usage CasesScenario:

1. Design a power "on" indicator light for a device powered by a 12V DC power adapter. A green LED is required.Parameter Selection:_FThe goal is a clearly visible but not glaring indicator light. Select the operating current (I
2. ) as 5mA.Resistance Calculation:_FFor safety design, use maximum V
   value 2.4V._{R = (V}Power supply_F- V_F) / I
   = (12V - 2.4V) / 0.005A = 9.6V / 0.005A = 1920 Ω.
3. The closest standard E24 resistor values are 1.8kΩ or 2.2kΩ. Choosing 2.2kΩ will result in a slightly lower current (approximately 4.36mA), which is acceptable and can extend the lifespan. P_{Power consumption check:}Resistor power dissipation P_F²= I²* R = (0.00436)
   P_LED* 2200 ≈ 0.042W. Standard 1/8W (0.125W) or 1/4W resistors are more than sufficient._FLED power consumption P_F= V
4. * I≈ 2.4V * 0.00436A ≈ 0.0105W (10.5mW), yana ƙasa da ƙimar 75mW.

PCB Layout:

Connect the resistor in series with the anode of the LED. Ensure the hole spacing matches the pin spacing where the LED leads extend from the body. Provide a keep-out area of at least 2mm around the LED root to facilitate soldering operations.

12. Principle Introduction

This LED is based on aluminum indium gallium phosphide (AlInGaP) semiconductor material. When a forward voltage is applied, electrons from the n-type region and holes from the p-type region are injected into the active region. When these carriers recombine, they release energy in the form of photons (light). The specific composition of the AlInGaP alloy determines the semiconductor's bandgap energy, which directly dictates the wavelength (color) of the emitted light. In this case, the alloy is designed to produce photons in the green spectrum, with a dominant wavelength of approximately 572 nanometers. A transparent epoxy lens is used to protect the semiconductor chip, shape the light output beam (forming a 45° viewing angle), and enhance the amount of light extracted from the package.