LTST-C295TGKSKT Bicolor SMD LED Datasheet - 0.55mm Ultra-Low Profile Height - Green/Yellow - 20mA/30mA - Technical Documentation

1. Product Overview

This document provides the complete technical specifications for the LTST-C295TGKSKT, a dual-color Surface-Mount Device (SMD) Light-Emitting Diode (LED). This component is designed for applications requiring two distinct colors, compact size, and high-brightness indication within a single package. Its key distinguishing feature is its extremely low profile height, making it suitable for space-constrained modern electronic designs.

This LED integrates two independent semiconductor chips within a standard EIA-compliant package: an Indium Gallium Nitride (InGaN) chip for emitting green light and an Aluminum Indium Gallium Phosphide (AlInGaP) chip for emitting yellow light. This dual-chip architecture allows for independent control of each color, enabling status indication, dual-color signaling, or simple color mixing depending on the drive circuit configuration. The device is supplied on industry-standard 8mm tape, wound onto 7-inch reels, facilitating high-speed automated pick-and-place assembly processes common in high-volume electronics manufacturing.

2. In-depth and Objective Interpretation of Technical Parameters

2.1 Viwango vya Juu Kabisa

Hizi viwango vya kawaida vinafafanua mipaka ya mkazo inayoweza kusababisha uharibifu wa kudumu wa kifaa. Hakuna uhakikisho wa uendeshaji kwenye au karibu na mipaka hii, na inapaswa kuepukwa katika muundo wa saketi.

• Matumizi ya nguvu (Pd):Chip ya mwanga wa kijani ni 76 mW, na chip ya mwanga wa manjano ni 75 mW. Kigezo hiki, pamoja na upinzani wa joto wa kifuniko na PCB, huamua mkondo wa juu unaoruhusiwa wa mwendelezo wa mbele ili kuzuia kuzidi kikomo cha joto la kiungo.
• Peak Forward Current (I_FP):Green light is 100 mA, yellow light is 80 mA. This value is specified at a 1/10 duty cycle and a 0.1ms pulse width. It indicates that the LED can withstand brief high-current pulses, making it suitable for multiplexed driving or pulse brightness applications, but not for DC operation.
• Direct forward current (I_F):Green light is 20 mA, yellow light is 30 mA. This is the recommended maximum continuous current for reliable long-term operation under normal conditions.
• Temperature range:Operating temperature: -20°C to +80°C; Storage temperature: -30°C to +100°C. The operating range is typical for commercial-grade LEDs. Designers must ensure that ambient temperature and self-heating do not cause the LED junction temperature to exceed its maximum rated temperature.
• Infrared Reflow Soldering Conditions:Can withstand 260°C for 10 seconds. This is crucial for Pb-free reflow soldering processes and must be strictly adhered to during PCB assembly.

2.2 Tabia za Umeme na Mwanga

Hizi ni vigezo vya kawaida vya utendaji vilivyopimwa chini ya hali maalum za majaribio kwenye Ta=25°C. Ni muhimu sana kwa usanifu wa saketi na ujumuishaji wa mfumo wa optiki.

• Nguvu ya mwanga (I_V):Katika I_F=20mA, hupimwa kwa msaada wa milikandela (mcd). Safu ya chipi ya kijani ni kuanzia 45.0 mcd (kiwango cha chini) hadi 280.0 mcd (kiwango cha juu). Safu ya chipi ya manjano ni kuanzia 28.0 mcd (kiwango cha chini) hadi 450.0 mcd (kiwango cha juu). Safu hii pana inasimamiwa kupitia mfumo wa kugawanya katika makundi (tazama Sehemu ya 3 kwa maelezo zaidi). Majaribio yalifanywa kwa kutumia kichujio kinachokaribia mkunjo wa majibu ya kuona ya wazi wa CIE.
• Angle of View (2θ_1/2):Both colors typically have a 130-degree angle. This is the full angle at which the luminous intensity drops to half of the axial value. A 130-degree angle indicates a very wide viewing pattern, suitable for applications requiring the LED to be visible from a broad range of angles.
• Peak Emission Wavelength (λ_P):Mwanga wa kijani kwa kawaida ni 525 nm, na mwanga wa manjano kwa kawaida ni 588 nm. Hii ndiyo urefu wa wimbi unaolingana na sehemu ya juu zaidi katika wigo wa utoaji.
• Urefu wa wimbi mkuu (λ_d):Mwanga wa kijani kwa kawaida ni 525.0 nm, na mwanga wa manjano kwa kawaida ni 587.0 nm. Thamani hii inatokana na chati ya rangi ya CIE na ni urefu wa wimbi mmoja unaofafanua rangi kama inavyohisiwa na jicho la binadamu. Ni kipimo kinachohusiana zaidi na hisia kuliko urefu wa wimbi wa kilele.
• Upana wa nusu ya mstari wa wigo (Δλ):Kawaida ya mwanga wa kijani ni 35 nm, na mwanga wa manjano ni 20 nm. Hii inaonyesha usafi wa wigo au upana wa bendi ya mwanga unaotolewa. Wigo wa LED ya AlInGaP ya manjano kwa kawaida ni nyembamba kuliko ile ya LED ya InGaN ya kijani.
• Voltage ya mbele (V_F):Katika I_F=20mA, kiwango cha juu cha kijani ni 3.50V, na kiwango cha juu cha manjano ni 2.40V. Hii ni muhimu sana katika kubuni saketi za kudhibiti mkondo. V_Fya juu ya chip ya kijani ni sifa ya teknolojia ya InGaN.
• Mkondo wa nyuma (I_R):Katika V_R=5V, zote mbili zina kiwango cha juu cha 10 μA.Uangalizi Muhimu:Kifaa hiki hakikusudiwa kufanya kazi kwa njia ya kinyume. Kutumia bias ya kinyume inayozidi 5V kunaweza kusababisha uharibifu wa papo hapo. Inapendekezwa sana kuchukua hatua za kinga katika mzunguko ili kuzuia voltage ya kinyume au muunganisho usio sahihi wa polarity.

3. Bin System Description

Ili kuhakikisha uthabiti wa rangi na mwangaza katika uzalishaji, LED zimegawanywa katika vikundi tofauti vya utendaji. LTST-C295TGKSKT hutumia mfumo wa kugawanya kwa nguvu ya mwanga kwa kila rangi.

3.1 Green Light Intensity Grading

The bin is defined by a letter code (P, Q, R, S), with minimum and maximum luminous intensity values (in mcd) given at 20mA. The tolerance for each bin is +/-15%. For example, bin 'P' covers 45.0 to 71.0 mcd. Designers should specify the required bin code when ordering to ensure brightness uniformity among multiple devices in an assembly.

3.2 Yellow Light Intensity Grading

The yellow LED chip employs a broader binning range, designated as N, P, Q, R, S, T, covering intensities from 28.0 mcd (minimum for bin N) to 450.0 mcd (maximum for bin T), each bin also featuring a +/-15% tolerance. The wider range accommodates the higher potential brightness of the AlInGaP material.

4. Uchambuzi wa Mkunjo wa Utendaji

While the datasheet references specific graphical data (e.g., Figure 1, Figure 6), the provided numerical data allows for the analysis of key relationships.

• IV relationship:Voltage ya mbele (V_F) is specified at a single test current (20mA). In practice, V_FInaungana na I_FIna uhusiano wa logarithmic, na pia inategemea joto. Kutumia chanzo cha mkondo wa mara kwa mara badala ya chanzo cha voltage ya mara kwa mara kwa kuendesha LED ni muhimu kwa pato la mwanga thabiti.
• Sifa za joto:Kwa kawaida, nguvu ya mwanga ya LED hupungua kadri joto la kiungo linavyoongezeka. Vigezo vilivyobainishwa hupimwa kwenye joto la mazingira la 25°C. Katika mazingira ya joto la juu au chini ya mkondo wa kuendesha wa juu, inapaswa kutazamiwa pato kupunguzwa. Joto la juu la uendeshaji la 80°C hutoa kikomo cha juu cha uendeshaji unaotegemewa.
• Spectral Distribution:Typical peak wavelength and dominant wavelength, along with spectral half-width, collectively define the color point. Green emission (525nm, 35nm FWHM) will appear as pure green, while yellow emission (587nm, 20nm FWHM) will be a saturated yellow, distinct from amber (~590nm) or pure green.

5. Taarifa za Mitambo na Ufungaji

5.1 Package Dimensions and Polarity

Kifaa hiki kinakubaliana na umbo la kawaida la kifurushi cha EIA SMD. Kipengele chake muhimu cha kiufundi ni urefu wake wa mm 0.55 tu, unaoelezewa kama "nyembamba sana". Mgawanyiko wa pini umeainishwa wazi: pini 1 na 3 zinatumika kwa anodi/kathodi ya kijani kibichi, pini 2 na 4 zinatumika kwa anodi/kathodi ya manjano. Muunganisho halisi wa ndani (anodi ya pamoja au kathodi ya pamoja) haujatajwa wazi katika maandishi yaliyotolewa, na lazima uthibitishwe kutoka kwa michoro ya kina ya kifurushi. Kutambua kwa usahihi upeo wa umeme ni muhimu ili kuzuia uharibifu wakati wa usakinishaji.

5.2 Recommended Pad Layout

The datasheet contains recommendations for land pattern dimensions on the PCB. Following these recommendations ensures reliable solder joints, proper heat dissipation, and prevents issues like tombstoning during reflow soldering. The land pattern design also affects the viewing angle and mechanical stability of the mounted component.

5.3 Tape and Reel Packaging

LEDs are supplied in 8mm wide embossed carrier tape, wound on 7-inch (178mm) diameter reels. Each reel contains 4000 pieces. This packaging conforms to ANSI/EIA 481 specification, ensuring compatibility with automated Surface Mount Technology (SMT) equipment. The carrier tape features pockets sealed with a top cover tape. The specification allows for a maximum of two consecutive missing components, and the minimum packaging quantity for the remaining order is 500 pieces.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Temperature Profile

A recommended infrared (IR) reflow soldering temperature profile is provided for lead-free assembly processes. Key parameters include the preheat zone (150-200°C), specific time above liquidus, and a peak temperature not exceeding 260°C with a maximum duration of 10 seconds. This profile is based on JEDEC standards and is intended as a general target. The actual profile must be characterized according to the specific PCB design, solder paste, and oven used in production.

6.2 Precautions for Manual Soldering

Ikiwa ununuzi wa mikono unahitajika, joto la chuma cha kuuza lisiwe zaidi ya 300°C, na wakati wa ununuzi mmoja usizidi sekunde 3. Joto la kupita kiasi au kuwasiliana kwa muda mrefu linaweza kuharibu kifurushi cha LED au waya za ndani za kuunganisha.

6.3 Kusafisha

Ikiwa usafishaji unahitajika baada ya ununuzi, tumia tu vilainishi vilivyobainishwa. Mwongozo unapendekeza kuzamisha LED katika ethanol au isopropanol kwa joto la kawaida kwa si zaidi ya dakika moja. Kutumia kemikali za kusafisha zisizobainishwa au zenye kutu kali kunaweza kuharibu lenzi ya plastiki au nyenzo za kifurushi, na kusababisha pato la mwanga kupungua au kushindwa mapema.

6.4 Masharti ya Uhifadhi

Uhifadhi sahihi ni muhimu kudumisha uwezo wa kulehemu. Mfuko wa kuzuia unyevu wenye dondakio usiofunguliwa unapaswa kuhifadhiwa kwenye ≤30°C na ≤90% unyevunyevu wa jamaa, na uhalali wa mwaka mmoja. Mara tu ufungaji asilia unapofunguliwa, vipengele vinapaswa kuhifadhiwa kwenye ≤30°C na ≤60% unyevunyevu wa jamaa. Inapendekezwa kukamilisha reflow ya infrared ndani ya wiki moja baada ya kufungua. Kwa uhifadhi wa muda mrefu zaidi nje ya mfuko asilia, vipengele vinapaswa kuhifadhiwa kwenye chombo kilichotiwa muhuri chenye dondakio au kikaushi cha nitrojeni. Vipengee vilivyohifadhiwa chini ya hali zisizofaa kwa zaidi ya wiki moja vinapaswa kuokwa kwenye takriban 60°C kwa angalau saa 20 kabla ya kusanyiko, ili kuondoa unyevu uliovutwa na kuzuia tukio la "popcorn" wakati wa mchakato wa reflow.

7. Mapendekezo ya Matumizi

7.1 Mazingira ya Kawaida ya Matumizi

LED hii yenye rangi mbili inafaa kabisa kwa matumizi ya hali na kiashiria ambapo nafasi ni ndogo na inahitaji kuwasilisha hali nyingi. Kwa mfano:

• Vifaa vya kielektroniki vinavyobebeka kwa watumiaji:Hali ya umeme/kujaa (kijani kibichi=imejaa, manjano=inajaa), taa ya kiashiria cha muunganisho (Bluetooth/Wi-Fi), au taa ya kiashiria cha hali kwenye simu janja, kompyuta kibao, vifaa vinavyovaliwa na vipokezi vya sauti visivyo na waya, vinafaidika na umbo lake nyembamba sana.
• Paneli za udhibiti za viwanda:Kiashiria cha Hali ya Mashine (Kijani = Inaendesha, Manjano = Kusubiri/Shida), Kiashiria cha Kiwango au Taa ya Uthibitisho kwenye Kiolesura cha Binadamu na Mashine (HMI).
• Taa za Ndani za Gari:Mwanga wa Nyuma wa Dashibodi wa Kitufe au Swichi, Taa za Mazingira, au Kiashiria cha Hali Kisicho Muhimu (kinahitaji Uthibitisho Maalum wa Ngazi ya Gari).
• Vifaa vya IoT na Vifaa vya Nyumba Bora:Hali ya mtandao, kiashiria cha shughuli za sensor, au onyo la kiwango cha betri.

7.2 Mazingatio ya Ubunifu

• Current Drive:Always use a series current-limiting resistor or a dedicated constant-current LED driver IC. Use the formula R = (V_{Power Supply}- V_F) / I_F Calculate the resistance value using the maximum V from the datasheet_Fto ensure I_Fdoes not exceed the limit. Remember that V for each color_FTofauti.
• Usimamizi wa joto:Ingawa matumizi ya nguvu ni ya chini, eneo la shaba la PCB au mashimo ya upitishaji joto ya kutosha yanapaswa kuhakikishwa, hasa wakati wa kuendesha karibu na mkondo wa juu zaidi au kwa halijoto ya juu ya mazingira, ili kuweka halijoto ya kiungo ndani ya mipaka.
• Ulinzi wa ESD:Mwongozo una onyo kuhusu kutokwa kwa umeme tuli (ESD). Vifaa hivi ni nyeti. Tekeleza taratibu salama za usindikaji wa ESD (kifungo cha mkono, kituo cha kazi kilichogundishwa) wakati wa usanikishaji, na katika matumizi ya mwisho, fikiria kuongeza diode ya kukandamiza voltage ya muda mfupi (TVS) au upinzani kwenye nyeti ikiwa inaweza kufichuliwa kwa tukio linalowezekana la ESD.
• Usanifu wa Kioo:Pembe ya kuona ya digrii 130 hutoa uwazi mpana. Kwa matumizi yanayohitaji boriti iliyolengwa zaidi, lenzi ya nje au kielekezi cha mwanga kinaweza kuhitajika. Lenzi ya "maji safi" inahakikisha upotovu mdogo wa rangi.

8. Ulinganisho wa Teknolojia na Tofauti

Tofauti kuu ya LTST-C295TGKSKT iko katika mchanganyiko wa utendaji wake:

• Umbo nyembamba sana (0.55mm):Ikilinganishwa na LED nyingi za kawaida za SMD (kawaida 0.6mm, 0.8mm au zaidi), hii ni faida kubwa, ikifanya iweze kutumika katika vifaa vya kisasa vyembamba zaidi.
• Rangi mbili kwenye kifurushi kimoja:Ikilinganishwa na kutumia LED mbili za rangi moja tofauti kufanya kazi kama hiyo, hii inaokoa nafasi kwenye PCB na kurahisisha usanikishaji.
• Teknolojia ya Chipu:Kutumia InGaN kutengeneza mwanga wa kijani, na AlInGaP kutengeneza mwanga wa manjano, inawakilisha nyenzo za kisasa za semiconductor zenye ufanisi wa juu, zinazotoa mwangaza mzuri na usawa wa rangi.
• Uzingatiaji:Inakidhi na viwango vya ROHS na ni bidhaa ya kijani, inahakikisha kufuata kanuni za kimazingira duniani kote.

9. Maswali Yanayoulizwa Mara kwa Mara (Kulingana na Vigezo vya Kiufundi)

Je: Ninaweza kuendesha LED ya kijani na ya manjano kwa wakati mmoja kwa mkondo wa moja kwa moja kamili?
A: Siyo. Thamani ya juu kabisa ya kiwango cha juu inabainisha matumizi ya nguvu ya kila chip (mwanga wa kijani 76mW, mwanga wa manjano 75mW). Kufanya kazi kwa wakati mmoja kwa 20mA (kijani) na 30mA (manjano) kutasababisha matumizi ya nguvu ya takriban 70mW (3.5V*20mA) na 72mW (2.4V*30mA) mtawalia, ambayo inakaribia kikomo cha kila moja. Jumla ya joto linalozalishwa lazima isimamiwe. Inashauriwa kurejelea hesabu za joto au kupunguza kidogo sasa wakati wa uendeshaji wa mwangaza kamili wa wakati mmoja.

Q: Kuna tofauti gani kati ya urefu wa wimbi la kilele na urefu wa wimbi kuu?
A: Urefu wa wimbi la kilele (λ_P) ni urefu wa wimbi wa kimwili wa sehemu yenye nguvu zaidi katika pato la wigo. Urefu wa wimbi kuu (λ_d) is a value calculated based on colorimetry, representing the single wavelength of a pure monochromatic light that appears identical to the LED's color to a standard human observer. λ_dIt is generally more useful for color matching in design.

Q: How to interpret the binning code when ordering?
A: The binning code (e.g., 'S' for green, 'T' for yellow) guarantees that the luminous intensity will fall within the specified minimum/maximum range for that code, with a +/-15% tolerance. For consistency in product appearance, it is crucial to specify a single binning code for all devices within a production lot. If not specified, you may receive LEDs from any bin within the product's overall range.

10. Uchambuzi wa Kesi Halisi za Ubunifu

Mazingira:Unda kiashiria cha nishati ya chini kwa kifaa kinachoshikwa mkononi, kinachotolewa na kisimamizaji cha 3.3V. Kiashiria kiwe kijani kibichi wakati voltage ya betri iko juu ya 3.6V, na kiwe manjano wakati voltage inashuka chini ya 3.5V.

Implementation Plan:A microcontroller with an Analog-to-Digital Converter (ADC) monitors the battery voltage. Two GPIO pins are used to control the LEDs. The circuit will be configured according to the internal pin arrangement (e.g., if it is common cathode, the cathode pin is grounded, and the microcontroller sinks current through a current-limiting resistor to light each anode). The resistor values will be calculated separately: R_{Green Light}= (3.3V - 3.5V) / 0.020A = ~ -10Ω (invalid). This indicates a problem: the V_F(max 3.5V) is too close to or exceeds the supply voltage (3.3V).

Solution:1) Use a lower current for the green LED (e.g., 10mA), which will reduce its V_F.2) Use a charge pump or boost converter to generate a slightly higher voltage (e.g., 4.0V) to drive the LED. 3) Use a green LED with a lower V_F. This case highlights the importance of checking V early in the design process based on the available power supply voltage._F.

11. Utangulizi wa Kanuni ya Uendeshaji

Diode ya mwanga (LED) ni kifaa cha semiconductor p-n junction kinachotoa mwanga kwa njia ya umeme-luminiscence. Wakati voltage ya mbele inatumika, elektroni kutoka eneo la aina-n na mashimo kutoka eneo la aina-p huingizwa kwenye eneo la makutano. Wakati hivi vichukua-nguvu vinaungana tena, nishati hutolewa. Katika semiconductors za kawaida kama vile silicon, nishati hii hasa ni joto. Katika semiconductors zenye pengo la bendi moja kwa moja kama vile InGaN na AlInGaP, sehemu kubwa ya nishati hii hutolewa kwa njia ya fotoni (mwanga). Urefu wa wimbi (rangi) wa mwanga unaotolewa umedhamiriwa na nishati ya pengo la bendi (E_g) ya nyenzo ya semiconductor, kulingana na fomula λ = hc/E_g. Nyenzo za InGaN hutumiwa kwa urefu wa wimbi mfupi (bluu, kijani), wakati nyenzo za AlInGaP hutumiwa kwa urefu wa wimbi mrefu (manjano, machungwa, nyekundu). Ufungaji wa LED yenye rangi mbili ni kifusi kinachobeba chips mbili za semiconductor huru zenye pengo tofauti la bendi.

12. Technology Trends

Uendelevu wa LED kama LTST-C295TGKSKT umefuata mwelekeo muhimu kadhaa wa tasnia:

• Kupunguzwa kwa ukubwa:Kupunguzwa endelevu kwa ukubwa wa kifurushi na urefu ili kufikia bidhaa za mwisho nyembamba na kompaktifu zaidi, kama inavyoonyeshwa na urefu wa sehemu ya 0.55mm.
• Kuongeza kiwango cha ushirikiano:Kuchanganya kazi nyingi (kama vile rangi mbili) katika kifurushi kimoja, ili kuokoa nafasi kwenye bodi ya mzunguko na kurahisisha usanikishaji.
• Ufanisi wa nyenzo:Uboreshaji endelevu wa ukuaji wa epitaxial wa nyenzo za InGaN na AlInGaP umesababisha ufanisi wa juu zaidi wa quantum ndani, kuruhusu mwangaza mkubwa zaidi kwa mikondo ya chini, au kupunguza matumizi ya nishati kwa pato sawa la mwanga.
• Ufungaji wa hali ya juu:Uboreshaji wa nyenzo za ufungaji na michakato umeimarisha utendaji wa joto, kuruhusu matumizi ya mikondo ya kuendesha ya juu zaidi katika vifurushi vidogo, na kuongeza uaminifu chini ya hali ngumu za mazingira.
• Ustahimilivu wa otomatiki:Kanuni za Usanifu wa Uzalishaji (DFM) huhakikisha vipengele vinavyolingana kabisa na mstari wa usanikishaji wa kiotomatiki wa kasi na usahihi, zikiwa na sifa kama ufungaji wa kawaida wa reeli za mkanda.