SMD LED LTST-E681VEWT Datasheet - Dimensions 2.8x3.5x1.9mm - Voltage 2.2V - Power 196mW - Red - Technical Documentation

1. Product Overview

LTST-E681VEWT ni LED ya juu ya mwangaza ya usakinishaji wa uso, iliyoundwa kwa matumizi ya kisasa ya elektroniki yanayohitaji mwongozo wa kuangaza unaoaminika na wenye ufanisi. Kifaa hiki hutumia nyenzo za semiconductor za AlInGaP (Aluminium Indium Gallium Phosphide) kutoa mwanga mwekundu mkali. Kina kifurushi cha kompaktiki kinacholingana na viwango vya tasnia na kinafanana na michakato ya usakinishaji ya otomatiki, ikifaa kwa uzalishaji mkubwa.

Faida kuu ya LED hii ni pamoja na kufuata maagizo ya RoHS (Vizuizi vya Vitu hatari), kuhakikisha usalama wa mazingira. Inafungwa kwenye mkanda wa kubeba wa 8mm, uliozungushwa kwenye reel yenye kipenyo cha inchi 7, ambayo ni usanidi wa kawaida wa vifaa vya kusakinisha otomatiki. Kifaa hiki pia kimeundwa kwa kufanana na mchakato wa kuunganishia kwa kuyeyusha kwa mionzi ya infrared, ambayo ni njia kuu ya kukusanya bodi za teknolojia ya kusakinishwa kwenye uso. Soko lake kuu lengwa linajumuisha elektroniki za watumiaji, paneli za udhibiti wa viwanda, taa za ndani za magari, na matumizi ya jumla ya viashiria vya mwanga ambapo nafasi ni ndogo na uaminifu ni muhimu sana.

2. In-depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation of the LED outside these values is not recommended.

• Power Dissipation (Pd):196 mW. This is the maximum power that the LED package can dissipate as heat when the ambient temperature (Ta) is 25°C. Exceeding this limit risks overheating and damaging the semiconductor junction, leading to reduced lifespan or catastrophic failure.
• Peak Forward Current (I_FP):100 mA. Hii ndiyo mkondo wa juu unaoruhusiwa wa msukumo wa mbele, uliobainishwa chini ya hali ya mzunguko wa kazi 1/10 na upana wa msukumo wa 1ms. Ni kubwa zaidi kuliko ukadiriaji wa DC, na huruhusu mwako wa muda mfupi wenye nguvu.
• Mkondo wa mbele wa DC (I_F):70 mA. Hii ndiyo mkondo wa juu unaoruhusiwa wa mbele unaoendelea ambao unaweza kutumiwa kwenye LED chini ya hali za kawaida za uendeshaji.
• Safu ya joto la uendeshaji:-40°C to +85°C. The LED is designed to operate normally within this ambient temperature range.
• Storage Temperature Range:-40°C to +100°C. The device can be stored within this wider temperature range without degradation when not in operation.

2.2 Electrical and Optical Characteristics

These parameters are measured under standard test conditions of Ta=25°C and I_F=50mA unless otherwise specified. They define the typical performance of the device.

• Luminous Intensity (I_V):900 hadi 2800 mcd (millicandela). Hii ni kipimo cha nguvu ya mwanga inayotambuliwa inayotolewa katika mwelekeo maalum. Safu mpana inaonyesha matumizi ya mfumo wa kiwango (angalia Sehemu ya 3 kwa maelezo zaidi). Upimaji ulifanywa kwa kutumia sensor iliyochujwa ili kukaribia majibu ya kuona ya mwanga ya jicho la binadamu (mkondo wa CIE).
• Pembe ya maono (2θ_1/2):120 digrii. Hii ni pembe kamili wakati nguvu ya mwanga inapungua hadi nusu ya thamani yake ya kipimo cha mhimili (0°). Pembe ya maono ya 120° inamaanisha muundo wa mwanga mpana na unaotawanyika, unaofaa kwa matumizi yanayohitaji kuonekana kwa upana.
• Peak Emission Wavelength (λ_P):632 nm (typical). This is the wavelength at which the spectral power distribution of the emitted light reaches its maximum. It falls within the red region of the visible spectrum.
• Dominant Wavelength (λ_d):624 nm (typical). Derived from the CIE chromaticity diagram, this is the single wavelength that best represents the LED color as perceived by the human eye. It is a key parameter for color specification.
• Spectral Line Half-Width (Δλ):20 nm (typical value). This is the width of the spectral emission at half its maximum power. The value of 20nm is characteristic of AlInGaP red LEDs, indicating relatively pure color.
• Forward voltage (V_F):2.2 V (typical value), with a tolerance of ±0.1V. This is the voltage drop across the LED when driven at the specified 50mA current. It is crucial for designing current-limiting circuits.
• Reverse current (I_R):At V_R=5V, the maximum is 10 μA. This parameter is for quality assurance testing only. This LEDis not designed for reverse bias operation.Applying reverse voltage in a circuit may damage it.

3. Binning System Description

Ili kuhakikisha uthabiti katika uzalishaji kwa wingi, LED hutengwa kwa vyeo kulingana na utendaji. LTST-E681VEWT hutumia mfumo wa kugawanya kwa vyeo unaotegemea nguvu ya mwanga chini ya 50mA.

Msimbo wa kugawanya (V2, W1, W2, X1, X2) unawakilisha safu ya kuongezeka kwa nguvu ya chini na ya juu ya mwanga. Kwa mfano, msimbo wa kugawanya X2 unajumuisha LED zenye nguvu kati ya 2240 mcd hadi 2800 mcd. Toleransi ya ±11% inatumika ndani ya kila kikundi. Mfumo huu unawaruhusu wabunifu kuchagua kiwango cha mwangaza kinachofaa kwa matumizi yao, kusawazisha gharama na utendaji. Mwongozo huu haunaonyeshi kuwa aina hii maalum ina vyeo tofauti vya urefu wa wimbi kuu au voltage ya mbele, ikionyesha udhibiti mkali wa vigezo hivi wakati wa utengenezaji.

4. Uchambuzi wa Mkunjo wa Utendaji

Although specific charts are mentioned but not fully detailed in the provided text, typical curves for such LEDs include:

• I-V (Current-Voltage) Curve:It demonstrates the exponential relationship between forward current and forward voltage. The curve exhibits a distinct "knee" voltage around 1.8-2.0V, beyond which the current increases rapidly with a small increase in voltage, highlighting why constant current drive is crucial.
• Luminous Intensity vs. Forward Current:Inaonyesha mwanga unaotolewa unalingana takriban na mkondo wa mbele, lakini kwa mikondo ya juu sana inaweza kuonyesha kujaa au kupungua kwa ufanisi.
• Uzito wa mwanga dhidi ya joto la mazingira:Inaonyesha mwanga unaotolewa hupungua kadiri joto la kiungo linavyoongezeka. Hii ni kipengele muhimu cha kuzingatia kwa matumizi yanayofanya kazi katika mazingira ya joto la juu.
• Usambazaji wa wigo:A graph showing the relationship between relative power and wavelength, with a peak at approximately 632nm and a full width at half maximum of about 20nm.
• Viewing Angle Distribution Diagram:A polar plot showing the angular distribution of light intensity, confirming a 120° viewing angle due to the diffuser lens and exhibiting a Lambertian or near-Lambertian distribution.

5. Taarifa za Mitambo na Ufungaji

5.1 Device Dimensions

The LED complies with the EIA standard SMD package. Key dimensions (unit: mm) are as follows:

• Urefu wa jumla: 3.2 mm
• Upana wa jumla: 2.8 mm
• Jumla urefu: 1.9 mm
• Upana wa lenzi: 2.2 mm
• Urefu wa lenzi: 3.5 mm
• Upana wa pini: 0.7 mm
• Urefu wa pini: 0.8 mm

Unless otherwise specified, the tolerance is ±0.2mm. Detailed dimensioning drawings are provided in the original specification document.

5.2 Polarity Identification and Pad Design

The anode (positive) connection is identified. To ensure soldering reliability, a recommended printed circuit board land pattern is provided, optimized for infrared and vapor phase reflow soldering processes. Correct pad design is crucial to prevent tombstoning (component lifting on one end) and to ensure reliable solder joints with appropriate solder paste volume.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Parameters

Kifaa hiki kinaendana na upakiaji wa joto wa infrared usio na risasi. Mkunjo wa joto unaopendekezwa unapaswa kufuata kiwango cha JEDEC J-STD-020B. Vigezo muhimu vinajumuisha:

• Upashaji joto kabla:150-200°C, kwa upeo wa sekunde 120, ili kupasha joto bodi ya mzunguko na vipengele hatua kwa hatua, kuamilisha flux na kuzuia mshtuko wa joto.
• Peak Temperature:Maximum 260°C. Time above liquidus (typically 217°C for lead-free solder) should be controlled.
• Total Soldering Time:Kwa kiwango cha juu cha joto kwa muda wa sekunde 10 kwa upeo. Urejeshaji wa solder umewekewa kikomo hadi mizunguko miwili tu.

Inasisitizwa kuwa mkunjo bora wa joto unategemea muundo maalum wa PCB, vipengele, mchanga wa solder na tanuru, na unapaswa kuchanganuliwa kwa kila matumizi.

6.2 Manual Soldering

Ikiwa ni lazima kufanya ufungaji kwa mkono, ni muhimu kuwa mwangalifu sana:

• Joto la chuma cha kuuza:Hadi 300°C.
• Weld time:Maximum 3 seconds per lead and only one weld cycle is allowed to prevent excessive thermal stress on the plastic package and internal bonding wires.

6.3 Storage Conditions

LED ni vifaa vyenye unyeti kwa unyevu.

• Ufungashaji uliowekwa muhuri:Hifadhi chini ya hali ya ≤30°C na ≤70% unyevunyevu wa jamaa. Maisha ya rafiki ni mwaka mmoja wakati kuhifadhiwa kwenye mfuko wa asili wa kuzuia unyevu ulio na kivundo kavu.
• ImefunguliwaVipengele lazima vitumike ndani ya saa 168 (siku 7) baada ya kufichuliwa kwa hewa ya mazingira (≤30°C / ≤60% RH). Ikiwa muda huu umepita, LED zinahitaji kukaushwa kabla ya kuuzalisha, kwa takriban 60°C kwa angalau saa 48, ili kuondoa unyevunyevu uliokithiri na kuzuia tukio la "popcorn" (ufunguo wa kifurushi kutokana na shinikizo la mvuke wakati wa reflow). Kwa uhifadhi wa muda mrefu wa mfuko uliofunguliwa, tumia chombo kilichotiwa muhuri chenye vikaushio au kikaushio kilichojaa nitrojeni.

6.4 Cleaning

Ikiwa usafishaji baada ya kuchomelea unahitajika, tumia tu vimumunyisho vya aina ya pombe vilivyobainishwa, kama vile ethanol au isopropanol, kusafisha kwa si zaidi ya dakika moja kwenye halijoto ya kawaida. Kemikali zisizobainishwa zinaweza kuharibu lenzi ya plastiki au ufungaji.

7. Ufungaji na Taarifa za Kuagiza

• Vipimo vya Ukanda wa Kubebea:LEDs are supplied in 8mm wide embossed carrier tape.
• Reel Specification:The carrier tape is wound on standard 7-inch (178mm) diameter reels.
• Kiasi kwa kila roll:2000 vipande.
• Kiasi cha chini cha kuagiza:Idadi iliyobaki ni vipande 500.
• Kigezo:Ufungashaji unalingana na kigezo cha ANSI/EIA-481.
• Modeli:LTST-E681VEWT. Naming conventions typically include series code, package/style, color/wavelength code, and possibly other variants.

8. Application Description and Design Considerations

8.1 Drive Circuit Design

LED is a current-driven device. To ensure stable and uniform brightness, especially when driving multiple LEDs in parallel, it is necessary to connect a current-limiting resistor in series with each LED.mustin series. The resistor value (R) is calculated using Ohm's Law: R = (V_{Power supply}- V_F) / I_F. Using typical V_F= 2.2V, desired I_F= 20mA, with a supply voltage of 5V: R = (5V - 2.2V) / 0.02A = 140 ohms. A standard 150-ohm resistor is suitable. Driving an LED directly from a voltage source without current limiting will result in excessive current and rapid failure.

8.2 Usimamizi wa Joto

Although the power dissipation is relatively low (196mW), effective thermal management remains important for maintaining long-term reliability and consistent light output. Ensure the PCB has sufficient copper area connected to the LED's thermal pad (if applicable) or leads to aid heat dissipation. Avoid prolonged operation at absolute maximum current and temperature limits.

8.3 Upeo wa Matumizi

LED hii inafaa kwa vifaa vya jumla vya elektroniki, kama vile vifaa vya ofisi, vifaa vya mawasiliano, na vifaa vya nyumbani. Haikusudiwa wala kuidhinishwa kwa matumizi muhimu ya usalama ambapo hitilafu inaweza kudhuru maisha au afya (k.m., anga, usaidizi wa maisha ya matibabu, udhibiti wa usafiri). Kwa matumizi kama hayo, ni lazima kununua vipengele vilivyo na uthibitisho unaolingana wa uaminifu.

9. Ulinganishi wa Kiufundi na Tofauti

The key differentiating advantages of the LTST-E681VEWT in its category include:

• Material Technology:Using AlInGaP, it generally offers higher efficiency and better temperature stability for red and amber light compared to older technologies like GaAsP.
• Brightness:Maximum intensity up to 2800mcd, providing high brightness within standard package dimensions.
• Perspective:The 120° wide viewing angle with a diffused lens provides excellent off-axis visibility, which is superior to narrow-beam LEDs for status indicators.
• Process Compatibility:Inakubaliana kabisa na usanidi wa kiotomatiki wa SMT na mkunjo wa joto wa kawaida wa reflow isiyo na risasi, na hupunguza utata na gharama za utengenezaji.

10. Maswali Yanayoulizwa Mara kwa Mara (FAQ)

Swali: Ikiwa voltage ya umeme yangu ni haswa 2.2V, naweza kuendesha LED hii bila kupinga mfululizo?
A: Hapana. Voltage ya mbele ina uvumilivu (±0.1V) na hubadilika kulingana na joto. Uvumilivu mdogo wa ziada wa voltage husababisha ongezeko kubwa lisilodhibitiwa la mkondo, linaloweza kuharibu LED. Hakikisha unatumia utaratibu wa kudhibiti mkondo.

Q: Je, kuna tofauti gani kati ya urefu wa wimbi la kilele na urefu wa wimbi kuu?
A: Urefu wa wimbi la kilele ni mahali ambapo nishati nyingi ya mwanga hutolewa kwa mwili. Urefu wa wimbi kuu unahesabiwa kulingana na viwianishi vya rangi, na unawakilisha rangi inayohisiwa na jicho la mwanadamu. Kwa LED za rangi moja kama LED hii nyekundu, zote mbili kwa kawaida ziko karibu, lakini urefu wa wimbi kuu ni kigezo muhimu cha kufanana kwa rangi.

Q: Bodi yangu ya mzunguko inasafishwa baada ya kuunganishwa. Je, LED hii inaendana?
Jibu: Uainishaji unabainisha kusafisha kwa kutia damu ya pombe (isopropanol au ethanol) tu, kwa muda usiozidi dakika moja. Vichujio vingi vya maji au vya nguvu vya kusafisha vinaweza kuharibu kifuniko. Tafadhali thibitisha ufanisi na mchakato wako maalum wa kusafisha.

Swali: Kwa nini kuna kikomo cha masaa 168 cha maisha ya kiwanda baada ya kufungua mfuko?
Jibu: Kifuniko cha plastiki kinachukua unyevu kutoka kwa hewa. Katika joto la juu la reflow soldering, unyevu huu unageuka haraka kuwa mvuke, na kusababisha shinikizo la ndani, ambalo linaweza kusababisha kifuniko kupasuka au tabaka la ndani kujitenga ("popcorn" effect). Kikomo cha masaa 168 na utaratibu wa kukaanga umewekwa ili kudhibiti hatari hii.

11. Mfano wa Matumizi Halisi

Mandhari:Buni kiashiria cha hali ya umeme kwa router ya DC 12V.
Hatua za Ubunifu:
1. Chagua Mkondo wa Kuendesha:Ili kupanua maisha ya taa na kupunguza joto, chagua I ya kihafidhina_F= 15mA.
2. Hesabu upinzani:Tumia V ya kawaida_F= 2.2V. R = (12V - 2.2V) / 0.015A = 653 ohms. Tumia thamani ya kawaida iliyo karibu zaidi, 680 ohms.
3. Kokotoa nguvu ya upinzani: P_R= I_F²* R = (0.015)²* 680 = 0.153W. A standard 1/4W (0.25W) resistor is sufficient.
4. PCB layout:Place the LED and its 680Ω resistor close together. Follow the recommended pad layout in the datasheet to ensure soldering reliability.
5. Assembly:Tumia mchoro wa joto wa reflow solder isiyo na risasi unaolingana na viwango vya JEDEC. Ikiwa bodi ya mzunguko haijaundwa baada ya mfuko wa LED kufunguliwa kwa zaidi ya siku 7, kwanza oka LED.

12. Kanuni ya Uendeshaji

Mwako wa mwanga katika LTST-E681VEWT unatokana na mwangaza wa umeme katika kiunganishi cha p-n cha semiconductor kilichotengenezwa kwa nyenzo za AlInGaP. Unapotumia voltage chanya inayozidi uwezo wa ndani wa kiunganishi, elektroni kutoka eneo la aina-n na mashimo kutoka eneo la aina-p huingizwa kwenye eneo lenye ufanisi. Wakati hivi vibebaji malipo vinapounganishwa tena, hutoa nishati kwa njia ya fotoni (mwanga). Muundo maalum wa aloi ya AlInGaP huamua nishati ya pengo la bendi, ambayo inafafanua moja kwa moja urefu wa wimbi la mwanga unaotolewa (rangi) — katika mfano huu, nyekundu, yenye urefu wa wimbi takriban 624-632 nm. Lensi ya epoksi iliyotawanyika juu ya chip hutumiwa kutoa mwanga kutoka kwenye semiconductor na kuunda usambazaji wake wa pembe kuwa muundo mpana wa digrii 120.

13. Mwelekeo wa Teknolojia

The optoelectronics industry for indicator LEDs continues to evolve. General trends associated with devices like the LTST-E681VEWT include:

• Efficiency Improvement:Maboresho ya Endelea ya Sayansi ya Nyenzo yanalenga kutoa lumens zaidi kwa kila watt, na hivyo kufikia mwangaza zaidi kwa mkondo sawa, au matumizi ya nguvu ya chini na joto kidogo kwa mwangaza sawa.
• Udogo:Ingawa vifurushi vya kawaida kama hivi bado vinaenea, kuna shinikizo la kuendelea la kupunguza eneo la kifurushi na urefu wake kwa ajili ya vifaa vya elektroniki vinavyozidi kuwa nyembamba.
• Uboreshaji wa Uaminifu:Maboresho ya nyenzo za ufungaji, mbinu za kushikanisha chipu na waya za kuunganisha zinalenga kupanua maisha ya kazi na kuboresha uvumilivu wa mkazo wa joto na wa mitambo.
• Uthabiti wa Rangi:Toleransi zaidi ya kiwango cha juu na udhibiti wa hali ya juu wa utengenezaji unapunguza tofauti za rangi na mwangaza kati ya vikundi, jambo muhimu kwa matumizi ya LED nyingi.
• Ujumuishaji:Kuna mwelekeo wa kuunganisha saketi ya kuendesha, vipengele vya ulinzi (kama vile diode za ESD) au chipi nyingi za LED kwenye kifuniko kimoja, ingawa katika matumizi mengi, LED tofauti bado ndio msingi kwa sababu ya unyenyekevu na faida za gharama.