LTL42FKGD Through Hole LED Lamp Datasheet - 5mm Diameter - 2.6V Forward Voltage - Green Color - 81mW Power - English Technical Document

1. Product Overview

LTL42FKGD yana da LED fitila da aka ɗora ta cikin rami wacce aka ƙera don nuna matsayi da haskakawa a cikin aikace-aikacen lantarki masu yawa. Tana da fakitin diamita na 5mm tare da ruwan tabarau mai watsawa kore, yana ba da faɗin kusurwar kallo da rarraba haske iri ɗaya. Na'urar tana amfani da fasahar semiconductor na AlInGaP (Aluminum Indium Gallium Phosphide) don fitar da haskenta, wanda aka sani da ingantacciyar inganci da kyakkyawan tsabtar launi a cikin bakan kore. An gina wannan LED don zama mara gubar kuma ya cika ka'idojin RoHS (Ƙuntata Abubuwa Masu Haɗari), wanda ya sa ya dace da buƙatun ƙera lantarki na zamani.

1.1 Fa'idodi na Asali

• Fitowar Haskakawa Mai Ƙarfi: Delivers typical luminous intensity of 240 mcd at a standard drive current of 20mA, ensuring bright and clear visibility.
• Energy Efficiency: Features low power consumption with a typical forward voltage of 2.6V, contributing to overall system energy savings.
• Design Flexibility: Available in a standard 5mm through-hole package, allowing for versatile mounting on printed circuit boards (PCBs) or panels. The wide 60-degree viewing angle ensures good visibility from various angles.
• Compatibility: The low current requirement makes it compatible with integrated circuit (IC) outputs without the need for complex driver circuits in many applications.
• Reliability: Designed for an operating temperature range of -40°C to +85°C, suitable for use in diverse environmental conditions.

1.2 Target Applications

This LED is engineered for broad applicability across multiple industries. Its primary function is status indication, but its brightness also allows for limited area illumination. Key application sectors include:

• Communication Equipment: Indicator lights for power, network activity, and system status on routers, switches, and modems.
• Computer Peripherals: Power and activity indicators on desktop computers, laptops, external drives, and keyboards.
• Consumer Electronics: Status lights on audio/video equipment, home appliances, toys, and portable devices.
• Home Appliances: Operational indicators on washing machines, microwaves, ovens, and other white goods.
• Industrial Controls: Panel indicators for machinery, control systems, test equipment, and instrumentation.

2. In-Depth Technical Parameter Analysis

The following section provides a detailed, objective interpretation of the key electrical, optical, and thermal parameters specified for the LTL42FKGD LED. Understanding these parameters is crucial for proper circuit design and reliable operation.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation at or near these limits is not recommended and will adversely affect reliability.

• Power Dissipation (Pd): 81 mW maximum. This is the total power (Forward Voltage * Forward Current) that can be safely dissipated as heat by the LED package at an ambient temperature (TA) of 25°C.
• DC Forward Current (IF): 30 mA maximum continuous current. Exceeding this value will generate excessive heat, leading to accelerated lumen depreciation and potential catastrophic failure.
• Peak Forward Current: 60 mA maximum, but only under pulsed conditions with a duty cycle of 10% or less and a pulse width of 10 microseconds or less. This rating is relevant for brief, high-intensity flashes.
• Derating: The maximum allowable DC forward current must be linearly reduced by 0.57 mA for every degree Celsius the ambient temperature rises above 50°C. This is a critical design consideration for high-temperature environments.
• Operating & Storage Temperature: The device can function from -40°C to +85°C and can be stored from -40°C to +100°C.
• Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured 2.0mm (0.079 inches) from the LED body. This defines the process window for hand or wave soldering.

2.2 Electrical & Optical Characteristics

These are the typical performance parameters measured under standard test conditions (TA=25°C). Designers should use the typical or maximum values as appropriate for their design margins.

• Luminous Intensity (Iv): Ranges from a minimum of 85 mcd to a maximum of 400 mcd at IF=20mA, with a typical value of 240 mcd. The actual value for a specific unit is determined by its bin code (see Section 4). The measurement uses a sensor filtered to match the photopic (human eye) response curve (CIE). A ±15% testing tolerance is applied to the bin limits.
• Viewing Angle (2θ1/2): 60 degrees. This is the full angle at which the luminous intensity drops to half of its value measured on the central axis (0 degrees). A 60-degree angle provides a good balance between focused brightness and wide visibility.
• Peak Emission Wavelength (λP): 574 nm. This is the wavelength at which the spectral power distribution of the emitted light is at its maximum.
• Dominant Wavelength (λd): Ranges from 563 nm to 573 nm, defining the perceived green color of the LED. It is derived from the CIE chromaticity coordinates and represents the single wavelength that best matches the LED's color.
• Spectral Line Half-Width (Δλ): 20 nm. This indicates the spectral purity; a smaller value means a more monochromatic (pure color) light. A 20nm width is typical for AlInGaP green LEDs.
• Forward Voltage (VF): 2.6V typical at IF=20mA, with a maximum of 2.6V. The minimum is 2.1V. This parameter has a distribution; designers must account for the maximum VF when calculating series resistor values to ensure adequate current limiting.
• Reverse Current (IR): 100 μA maximum when a reverse voltage (VR) of 5V is applied. Important Note: This LED is not designed for reverse-bias operation. This test condition is for characterization only. Applying a continuous reverse voltage can damage the device.

3. Binning System Specification

To ensure consistency in brightness and color for production applications, LEDs are sorted into performance bins. The LTL42FKGD uses a two-dimensional binning system.

3.1 Luminous Intensity Binning

Units are sorted based on their measured luminous intensity at 20mA. The bin code is marked on the packaging.

• Bin EF: 85 mcd (Min) to 140 mcd (Max)
• Bin GH: 140 mcd (Min) to 240 mcd (Max)
• Bin JK: 240 mcd (Min) to 400 mcd (Max)

Tolerance on each bin limit is ±15%.

3.2 Dominant Wavelength Binning

Units are also sorted by their dominant wavelength, which correlates directly with the shade of green.

• Bin H05: 563.0 nm (Min) to 566.0 nm (Max)
• Bin H06: 566.0 nm (Min) to 568.0 nm (Max)
• Bin H07: 568.0 nm (Min) to 570.0 nm (Max)
• Bin H08: 570.0 nm (Min) to 573.0 nm (Max)

Tolerance on each bin limit is ±1 nm.

A complete product order will be specified with both an intensity bin code (e.g., GH) and a wavelength bin code (e.g., H07) to guarantee both brightness and color consistency within the lot.

4. Performance Curve Analysis

While specific graphical data is referenced in the datasheet, the typical relationships between key parameters are described below. These curves are essential for understanding device behavior under non-standard conditions.

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

The LED exhibits a non-linear I-V characteristic typical of a diode. The forward voltage (VF) has a positive temperature coefficient, meaning it decreases slightly as the junction temperature increases for a given current. The curve shows the threshold voltage (where current begins to flow significantly) is around 1.8V to 2.0V for AlInGaP green LEDs, rising to the typical 2.6V at 20mA.

4.2 Ƙarfin Haskakawa da Ƙarfin Gaba

Fitowar haske (ƙarfin haskakawa) yana daidai da ƙarfin gaba a cikin kewayon aiki na yau da kullun (misali, har zuwa 30mA). Duk da haka, inganci (lumens kowace watt) na iya kololuwa a ƙarfin lantarki ƙasa da matsakaicin ƙima. Tuka LED a ƙarfin lantarki mafi girma yana ƙara fitarwa amma kuma yana haifar da ƙarin zafi, wanda zai iya rage inganci da dogon lokaci aminci.

4.3 Luminous Intensity vs. Ambient Temperature

The light output of an LED decreases as the junction temperature rises. While the AlInGaP material is more temperature-stable than some other LED types, a derating in output is expected as the ambient temperature approaches the maximum operating limit. This is why thermal management (e.g., not exceeding current ratings) is important for maintaining consistent brightness.

4.4 Spectral Distribution

The spectral output curve centers around the peak wavelength of 574 nm with a characteristic half-width of 20 nm. The dominant wavelength (λd), which defines the color point, is calculated from this spectrum. The curve is generally Gaussian in shape.

5. Mechanical & Package Information

5.1 Outline Dimensions

The LED conforms to the standard 5mm round through-hole package dimensions. Key mechanical specifications include:

• Lead diameter: Standard 0.6mm.
• Spacing ya Lead: 2.54mm (0.1 inch) nominal, inapimwa mahali ambapo nyuzi zinatoka kwenye mwili wa kifurushi.
• Diameter ya Mwili: 5.0mm nominal.
• Total height: Approximately 8.6mm from the bottom of the leads to the top of the dome lens, though this can vary slightly.
• Tolerance: ±0.25mm on most linear dimensions unless otherwise specified.
• Protruded resin under the flange is a maximum of 1.0mm. This is important for PCB layout to ensure the LED sits flush on the board.

5.2 Polarity Identification

The LED has two axial leads. The longer lead is the anode (positive, A+), and the shorter lead is the cathode (negative, K-). Additionally, the cathode side of the LED flange (the flat rim at the base of the lens) often has a small flat spot or notch. Always verify polarity before soldering to prevent reverse connection, which can damage the device.

6. Soldering & Assembly Guidelines

Proper handling and soldering are critical to prevent mechanical or thermal damage to the LED.

6.1 Storage Conditions

For long-term storage, keep LEDs in their original moisture-barrier packaging. The recommended storage ambient is ≤30°C and ≤70% relative humidity. If removed from the original packaging, use the LEDs within three months. For extended storage outside the original bag, store them in a sealed container with desiccant or in a nitrogen-purged desiccator to prevent moisture absorption, which can cause "popcorning" during soldering.

6.2 Lead Forming

If leads need to be bent for mounting, this must be done before soldering and at room temperature. Bend the leads at a point at least 3mm away from the base of the LED lens. Do not use the LED body or the lead frame as a fulcrum. Apply the minimum force necessary to avoid stressing the internal wire bonds.

6.3 Cleaning

If cleaning is required after soldering, use only alcohol-based solvents such as isopropyl alcohol (IPA). Avoid aggressive or ultrasonic cleaning that could damage the epoxy lens or internal structure.

6.4 Soldering Process Parameters

Hand Soldering (Iron):

• Maximum Iron Temperature: 350°C
• Maximum Soldering Time: 3 seconds per lead
• Minimum Distance from Lens Base: 2.0mm. The solder joint must not wick up the lead closer than this to the plastic body.
• Do not immerse the lens in solder.

Wave Soldering:

• Maximum Pre-heat Temperature: 100°C
• Maximum Pre-heat Time: 60 seconds
• Maximum Solder Wave Temperature: 260°C
• Maximum Contact Time: 5 seconds
• Minimum Dipping Position: No lower than 2mm from the base of the epoxy lens.

Critical Note: Infrared (IR) reflow soldering is not suitable for this through-hole LED product. The epoxy lens cannot withstand the high temperatures of a reflow oven profile. Excessive soldering temperature or time can cause lens deformation, cracking, or internal failure.

7. Packaging & Ordering Information

7.1 Packaging Specification

The LEDs are packaged in anti-static bags to prevent ESD damage. The standard packing hierarchy is:

1. Packing Bag: Contains 1000, 500, 200, or 100 pieces. The bag is labeled with the part number, quantity, and bin codes (Intensity and Wavelength).
2. Inner Carton: Contains 10 packing bags. The total quantity per inner carton is typically 10,000 pieces (when using 1000-piece bags).
3. Master/Outer Carton: Contains 8 inner cartons. The total quantity per master carton is typically 80,000 pieces.

For shipping lots, only the final pack may contain a non-full quantity.

8. Application Design Recommendations

8.1 Drive Circuit Design

LED ni kayan aiki ne da ke tafiyar da shi ta hanyar halin yanzu. Haskensa yana sarrafa shi ta hanyar halin yanzu na gaba (IF), ba ƙarfin lantarki ba. Abu mafi mahimmanci a cikin ƙira shine resistor mai iyakance halin yanzu.

Recommended Circuit (Circuit A): Yi amfani da resistor na jerin don kowane LED. Ana ƙididdige ƙimar resistor (R) ta amfani da Dokar Ohm: R = (Vsupply - VF_LED) / IF. Yi amfani da matsakaicin VF daga takardar bayanai (2.6V) don ƙirar mai ra'ayin mazan jiya wacce ke tabbatar da cewa halin yanzu bai taɓa wuce IF da ake so ba ko da tare da bambancin LED-zuwa-LED.

Misali: Don wadata na 5V da manufa IF na 20mA: R = (5V - 2.6V) / 0.020A = 120 Ohms. Za a zaɓi madaidaicin ƙimar daidaitaccen ƙima (misali, 120Ω ko 150Ω), kuma dole ne ƙimar wutar lantarki ta isa (P = I²R).

Da'ira don Gujewa (Da'ira B): Do not connect multiple LEDs directly in parallel from a single current-limiting resistor. Small variations in the forward voltage (VF) characteristic between individual LEDs will cause severe current imbalance. One LED with a slightly lower VF will draw disproportionately more current, leading to uneven brightness and potential overstress of that LED.

8.2 Electrostatic Discharge (ESD) Protection

The LED is sensitive to electrostatic discharge. Standard ESD precautions must be followed during handling and assembly:

• Ma'aikata yakamata su sanya bel ɗin wuyan hannu mai ƙasa ko safofin hannu masu hana tashin hankali.
• Duk tashoshin aiki, kayan aiki, da kayan aiki dole ne a ƙasa da su yadda ya kamata.
• Use conductive or dissipative mats on work surfaces.
• Store and transport LEDs in ESD-protective packaging.
• Consider using an ionizer to neutralize static charges that may accumulate on the plastic lens during handling.

8.3 Thermal Considerations

While this is a low-power device, thermal management is still important for longevity. Do not exceed the absolute maximum ratings for power dissipation and forward current. Adhere to the derating curve above 50°C ambient. Ensure adequate spacing between LEDs on a PCB to allow for heat dissipation and avoid creating local hot spots.

9. Technical Comparison & Differentiation

The LTL42FKGD, as a standard 5mm AlInGaP green LED, occupies a well-established position in the market. Its key differentiators are defined by its specific performance bins.

• vs. Lower-Brightness Green LEDs: Units binned in the JK range (240-400 mcd) offer significantly higher luminous intensity than generic "standard brightness" green LEDs, making them suitable for applications requiring high visibility or used behind lightly tinted lenses/diffusers.
• vs. Other Green Technologies: Compared to older Gallium Phosphide (GaP) green LEDs, AlInGaP technology provides higher efficiency and a more saturated, "true" green color (dominant wavelength in the 560-570nm range vs. 555nm for GaP).
• vs. Blue/Yellow-Based "Green" LEDs: Some white or green LEDs use a blue chip with a yellow phosphor, which can have a different spectral quality (broader spectrum) and potentially lower color purity than a direct-emitting AlInGaP green LED.
• Primary Advantage: Its main advantage is a combination of proven reliability, ease of use (through-hole), good efficiency, and the availability of tight brightness and color binning for consistent appearance in production runs.

10. Frequently Asked Questions (Based on Technical Parameters)

Q1: Can I drive this LED directly from a 3.3V or 5V microcontroller pin?
A: A'a, ba kai tsaye ba. Duk da cewa ƙarfin gaba (~2.6V) ya fi ƙananan wadannan wadatar wutar lantarki, LED dole ne ya zama mai iyakancewar halin yanzu. Haɗa shi kai tsaye zai yi ƙoƙarin jawo yawan halin yanzu, mai yuwuwar lalata duka LED da fil ɗin microcontroller. Koyaushe yi amfani da resistor na jerin kamar yadda aka bayyana a Sashe na 8.1.

Q2: Wane ƙimar resistor ya kamata in yi amfani da shi don wadatar 12V?
A: Yin amfani da dabara R = (12V - 2.6V) / 0.020A = 470 Ohms. Ƙarfin da aka watsar a cikin resistor shine P = (0.020A)² * 470Ω = 0.188W, don haka madaidaicin resistor 1/4W (0.25W) ya isa. Resistor 470Ω ko 560Ω zai dace.

Q3: Me yasa akwai mafi ƙarancin ƙarfin gaba (2.1V) da aka jera?
A: Ƙarfin lantarki na gaba yana da rarraba a cikin raka'a samarwa saboda ɗan bambance-bambance a cikin kayan semiconductor da tsarin masana'antu. Mafi ƙarancin 2.1V shine ƙarshen ƙasan wannan rarraba. Ƙira tare da ƙimar yau da kullun ko mafi girma yana tabbatar da cewa kewayen yana aiki daidai ga duk raka'a.

Q4: Shin zan iya amfani da wannan LED a waje?
A: Takardar bayanan ta bayyana cewa yana da kyau ga alamun cikin gida da na waje. Kewayon zafin aiki (-40°C zuwa +85°C) yana goyan bayan amfani na waje. Duk da haka, don tsayayyen fallasa yanayi kai tsaye, yi la'akari da ƙarin kariya (lullube na yanayi akan PCB, wani akwati mai rufi) saboda ruwan tabarau na epoxy na iya lalacewa daga tsayayyen fallasa UV ko shigar danshi cikin shekaru da yawa.

Q5: Yaya za a fassara lambobin kwandon sa’ad da ake yin oda?
A: Dole ne ka ƙayyade duka Ƙarfin Ƙarfi (misali, GH) da Bin Tsawon Tsayi (misali, H07) don samun rukunin da ya dace. Idan ba ka ƙayyade ba, za ka iya samun gauraye, wanda zai haifar da bambance-bambancen haske da launi a cikin samfurinka. Ga yawancin aikace-aikace, ƙayyade tsakiyar kwandon (GH don ƙarfi, H06/H07 don tsawon tsayi) kyakkyawan aiki ne.

11. Misalan Aikace-aikace na Aiki

Example 1: Multi-Channel Status Indicator Panel
In an industrial control box, ten LTL42FKGD LEDs (binned GH/H07) are used on a front panel to indicate the status of ten different sensors or machine states. Each LED is driven by a separate output of a 5V logic buffer IC (e.g., 74HC244). A single 120Ω resistor is placed in series with each LED. The consistent binning ensures all ten lights have a uniform green color and very similar brightness, providing a professional appearance. The wide 60-degree viewing angle allows the status to be seen from various operator positions.

Example 2: Backlighting for a Membrane Switch
LTL42FKGD LED guda (JK bin da aka yi don ƙarin haske) ana sanya shi a bayan wani alama mai wucewa a kan maɓalli na membrane. Ana sarrafa shi ta hanyar microcontroller GPIO fil ɗin ta hanyar resistor 150Ω daga wadata 3.3V. Rukunin LED ɗin da aka watsa yana taimakawa ƙirƙirar haske daidai gwargwado a ƙarƙashin alamar. Ƙarancin buƙatun yanzu (~13mA aka lissafta: (3.3V-2.6V)/150Ω) yana cikin ikon fil ɗin GPIO, yana sauƙaƙe ƙira.

12. Ka'idar Aiki

LTL42FKGD wata tushen haske ce ta semiconductor bisa ga haɗin p-n da aka kafa daga kayan AlInGaP (Aluminum Indium Gallium Phosphide). Lokacin da aka yi amfani da ƙarfin lantarki na gaba wanda ya wuce bakin kofa na diode, electrons daga yankin n-type da ramuka daga yankin p-type ana allurar su cikin yankin aiki (haɗin). Lokacin da waɗannan masu ɗaukar caji (electrons da ramuka) suka sake haɗuwa, suna sakin makamashi a cikin nau'in photons (ɓangarorin haske). Takamaiman abun da ke cikin gawa na AlInGaP yana ƙayyade makamashin bandgap na semiconductor, wanda kai tsaye yana ƙayyade tsayin raƙuman ruwa (launi) na photons ɗin da aka fitar—a wannan yanayin, hasken kore tare da tsayin raƙuman ruwa mai rinjaye kusan 570 nm. Ruwan tabarau na epoxy yana aiki don kare guntuwar semiconductor, siffanta fitowar haske (ƙirƙirar kusurwar kallo na digiri 60), da watsa haske don laushin bayyanarsa.

13. Mienendo ya Teknolojia

LED za kupenya-kwenye-tundu kama LTL42FKGD zinawakilisha teknolojia iliyokomaa na yenye kuaminika sana. Mwelekeo wa jumla katika tasnia ya LED unaelekea kwenye vifurushi vya vifaa vya kushika-uso (SMD) (k.m., 0603, 0805, 3528) kwa miundo mipya mingi kutokana na ukubwa wao mdogo, ufaao kwa usanikishaji wa otomatiki wa kuchukua-na-kuweka, na umbo la chini. Hata hivyo, LED za kupenya-kwenye-tundu zinabaki kuwa na umuhimu mkubwa katika maeneo kadhaa: kwa utengenezaji wa vielelezo na matumizi ya wapenzi kutokana na urahisi wa kuuza kwa mkono; katika matumizi yanayohitaji kuaminika sana na muunganisho thabiti wa mitambo (usioathiriwa na mtikisiko); kwa usakinishaji wa paneli ambapo waya zinaweza kushikiliwa moja kwa moja kwenye chasis; na katika mazingira ya kielimu. Teknolojia yenyewe inaendelea kuona uboreshaji wa hatua kwa hatua katika ufanisi (utoaji zaidi wa mwanga kwa wati) na uthabiti wa rangi kupitia michakato ya juu ya ukuaji wa epitaxial na uchambuzi wa makundi, hata ndani ya miundo ya vifurushi iliyokua kama taa ya 5mm.