LTD-5221AJF LED Digital Tube Datasheet - 0.56-inch Character Height - AlInGaP Yellow-Orange - 2.6V Forward Voltage - Technical Documentation

1. Product Overview

LTD-5221AJF ni moduli ya kuonyesha ya sehemu saba ya nambari yenye utendaji wa hali ya juu, iliyoundwa kwa matumizi yanayohitaji usomaji wa nambari ulio wazi, mkali na wenye matumizi ya nishati ya chini. Kazi yake kuu ni kutoa maonyesho ya hali ya juu ya uwazi kwa vifaa vya nambari, bidhaa za elektroniki za watumiaji na paneli za udhibiti wa viwanda.

Faida kuu ya kifaa hiki iko katika chipi yake ya LED inayotumia nyenzo za semiconductor za alumini-indiamu-gali-fosforasi (AlInGaP). Mfumo huu wa nyenzo unajulikana kwa ufanisi wake wa juu wa kutolea mwanga katika safu ya mwanga ya nyekundu hadi manjano-machungwa na usafi bora wa rangi. Kionyeshi hiki hutumia paneli ya rangi ya kijivu nyepesi na rangi nyeupe ya sehemu za nambari, ambayo husaidia kufikia tofauti kubwa ya rangi, hata katika hali mbalimbali za mwanga wa mazingira.

Kionyeshi hiki kimeainishwa kama kifaa cha mkondo wa chini, kilichojaribiwa na kuchaguliwa kwa makusudi kwa utendaji bora chini ya mkondo wa chini wa kuendesha. Muundo wake unalenga kutoa muonekano bora wa herufi, mwangaza wa juu na pembe pana ya maoni, kuhakikisha kuwa inaonekana wazi kutoka kwa pembe nyingi. Muundo thabiti hutoa uaminifu wa asili na maisha marefu ya utumiaji, na kufanya iwe inafaa kwa matumizi yanayohitaji uthabiti mkubwa.

1.1 Core Features and Target Applications

Sifa muhimu za bidhaa hii zinafafanuliwa kwa urefu wa herufi wa inchi 0.56 (milimita 14.22), unaopata usawa mzuri kati ya ukubwa na uwezo wa kusomeka. Sehemu za maonyesho yake zinaendelea na zimegawanyika sawasawa, zikionyesha uzuri rahisi na wa kitaalam. Mahitaji yake ya nguvu ya chini ni faida kubwa kwa vifaa vinavyotumia betri au vinavyohitaji usikivu wa matumizi ya nishati.

Kifaa hiki huainishwa kulingana na nguvu ya mwanga, ambayo inamaanisha kuwa vitengo hupangwa au kuchujwa kulingana na pato lao la mwanga, na hivyo kuhakikisha usawa wa mwangaza kati ya maonyesho mengi katika bidhaa moja. Hii ni muhimu sana kwa matumizi kama vile paneli za mita zenye tarakimu nyingi au alama za alama.

Soko lengwa na matumizi ya kawaida ni pamoja na vifaa vya kupimia vinavyobebeka, vifaa vya matibabu, dashibodi za magari (kwa maonyesho ya ziada), paneli za udhibiti wa vifaa vya nyumbani, vituo vya uhakiki wa mauzo, na maonyesho ya timer/hisaidizi viwango vya viwanda. Uaminifu na utendaji wake hufanya iwe chaguo bora kwa bidhaa za elektroniki za kiwango cha watumiaji na kitaalamu.

2. Uchambuzi wa Kina wa Vigezo vya Kiufundi

The electrical and optical characteristics of LTD-5221AJF are specified under standard test conditions with an ambient temperature (TA) of 25°C. A deep understanding of these parameters is crucial for proper circuit design and ensuring long-term reliability.

2.1 Viwango vya Juu Kabisa

These ratings define the stress limits that may cause permanent damage to the device and are not applicable to normal operating conditions.

• Power dissipation per segment:70 mW. This is the maximum power that a single LED segment can safely dissipate without causing overheating.
• Peak forward current per segment:90 mA. This is only allowed under pulse conditions (0.1 ms pulse width, 1/10 duty cycle), such as in multiplexed drive schemes, to achieve higher instantaneous brightness.
• Continuous forward current per segment:25 mA at 25°C. This current is linearly derated at a rate of 0.33 mA/°C when the ambient temperature exceeds 25°C. This derating is critical for thermal management.
• Reverse voltage per segment:5 V. Exceeding this voltage under reverse bias may damage the PN junction of the LED.
• Operating and storage temperature range:-35°C hadi +85°C. Upeo huu mpana unahakikisha utendaji katika mazingira magumu.
• Joto la kulehemu:Kifaa kinaweza kustahimili joto la kilele la 260°C kwa sekunde 3 kwenye umbali wa inchi 1/16 (takriban mm 1.6) chini ya ndege ya usakinishaji.

2.2 Electrical and Optical Characteristics

These parameters describe the performance of the device under normal operating conditions.

• Average luminous intensity (Iv):At a forward current (IF) of 1 mA, the range is from 320 μcd (minimum) to 700 μcd (typical). This extremely low drive current highlights its high efficiency. Intensity measurements are performed using a filter that simulates the human eye's photopic response (CIE curve).
• Forward voltage (VF) per segment:The typical value is 2.6 V, with a maximum of 2.6 V at IF=20 mA. The minimum value is 2.05 V. This parameter is crucial for designing current-limiting circuits.
• Peak emission wavelength (λp):611 nm. This is the wavelength at which the emission intensity is highest, defining the yellow-orange color.
• Dominant Wavelength (λd):605 nm. This is the wavelength perceived by the human eye and is closely related to the chromaticity point.
• Spectral line half-width (Δλ):17 nm. This indicates color purity; a narrower width means the color is more saturated and purer.
• Reverse current per segment (IR):The maximum is 100 μA at a reverse voltage (VR) of 5V.
• Luminous intensity matching ratio (Iv-m):Maximum 2:1. This parameter specifies the maximum allowable ratio between the brightest and darkest segments within a single digit under identical driving conditions (IF=1mA) to ensure uniformity.

3. Grading and Classification System

The datasheet clearly states that the device is "classified by luminous intensity." This implies the existence of a binning process.

3.1 Luminous Intensity Grading

Ingawa hati hii haitoi msimbo maalum wa kikundi, utendaji halisi unahusisha kupima kila onyesho au kila kundi la LED, na kuzigawa (kikundi) kulingana na mwanga unaozalisha unaopimwa chini ya mkondo wa kawaida wa kupima (k.m., 1mA au 20mA). Hii inawaruhusu watengenezaji kununua onyesho zenye mwangaza wa chini uliothibitishwa au zilizo katika anuwai maalum ya mwangaza, na kuhakikisha muunganiko wa kuona wa tarakimu zote katika matumizi ya onyesho yenye tarakimu nyingi. Wakati muunganiko ni kigezo muhimu cha kubuni, wabunifu lazima watazume hati maalum za kikundi za mtengenezaji ili kupata misimbo inayopatikana na vipimo.

4. Uchambuzi wa mkunjo wa utendaji

Vipimo vya karatasi vinataja "Mikunjo ya Kawaida ya Umeme/Optiki," ambayo ni zana muhimu za kuelewa tabia ya kifaa zaidi ya data ya nukta moja ya jedwali.

4.1 Ufafanuzi wa mkunjo wa kawaida

Although no specific charts are plotted in the provided text, the standard curves for such devices typically include:

• Forward Current vs. Forward Voltage (I-V Curve):This nonlinear curve shows the relationship between the voltage across the LED and the current flowing through it. It is crucial for selecting the appropriate current-limiting resistor or designing a constant-current driver. The "knee point" of this curve is typically around the standard VF value.
• Luminous Intensity vs. Forward Current (I-L Curve):Grafu hii inaonyesha jinsi pato la mwanga linavyobadilika kadri mkondo wa kuendesha unavyoongezeka. Kwa kiwango fulani kawaida huwa na mstari wa moja kwa moja, lakini kwenye mikondo ya juu sana inaweza kufikia kiwango cha juu kabisa. Mkunjo huu unathibitisha ufanisi wa juu kwenye mikondo ya chini (kama inavyoonyeshwa na sehemu ya majaribio ya 1mA ya Iv).
• Nguvu ya mwanga dhidi ya joto la mazingira:Mkunjo huu unaonyesha kupungua kwa pato la mwanga kwa sababu ya joto. Kadri halijoto inavyopanda, ufanisi wa LED hupungua, na kusababisha nguvu ya mwanga kupungua kwa mkondo sawa wa kuendesha. Hii inasisitiza umuhimu wa kupunguzwa kwa mkondo kama ilivyobainishwa katika viwango vya juu kabisa.
• Mkunjo wa usambazaji wa wigo:This graph will display the relative intensity of emitted light at different wavelengths around the 611 nm peak, with a width defined by the 17 nm FWHM parameter.

Designers should use these curves to predict performance under non-standard conditions, such as different drive currents or operating temperatures.

5. Maelezo ya Mitambo na Ufungaji

5.1 Package Dimensions and Tolerances

The physical outline and key dimensions of the device are provided in the drawing (referenced but not shown). All dimensions are in millimeters, with a standard tolerance of ±0.25 mm (0.01 in) unless otherwise specified in feature-specific notes. This information is critical for PCB layout, ensuring proper pad and aperture design, and mechanical integration into the final product enclosure.

5.2 Pin Connections and Internal Circuitry

LTD-5221AJF is a two-digit, common-anode display. The internal circuit diagram and pin connection table are crucial for correct wiring.

• Configuration:Common anode. This means the anodes of all LEDs for each digit are internally connected together. To illuminate a segment, its corresponding cathode pin must be driven low (connected to ground or a current sink), while the common anode for that digit is driven high (connected to VCC through a current-limiting resistor).
• Pinout:This 18-pin device assigns specific pins to the cathodes for segments A-G and the decimal point (D.P.) of digit 1 and digit 2, as well as to two common anode pins (one for each digit). Pin 1 is marked as "No Connection" (N.C.).
• Nukta ya desimali:Uainishaji unabainisha "nukta ya desimali ya kulia", inayoonyesha nafasi ya nukta ya desimali inayohusiana na nambari.

Usanidi huu wa anode ya pamoja kawaida hupendelewa katika mifumo inayotegemea microcontroller, kwa sababu pini za I/O kwa kawaida zina uwezo mkubwa wa kuvuta sasa (kudhibiti kiwango cha chini) kuliko kutoa sasa (kudhibiti kiwango cha juu).

6. Soldering and Assembly Guide

Absolute Maximum Ratings hutoa vigezo muhimu vya uchomeaji: kifaa kinaweza kustahimili joto la kilele cha 260°C kilichopimwa chini ya ndege ya usakinishaji kwa milimita 1.6 kwa sekunde 3. Hii inalingana na mkunjo wa kawaida wa joto wa reflow isiyo na risasi.

6.1 Recommended Practices

• Uuzaji wa Solder ya Reflow:Tumia mkunjo wa joto wa kawaida wa solder isiyo na risasi ya reflow, na kiwango cha juu cha joto kisizidi 260°C. Wakati ulio juu ya mstari wa kioevu (mfano 217°C) unapaswa kudhibitiwa ili kupunguza mkazo wa joto kwenye kifuniko cha plastiki na waya za ndani za kuunganisha.
• Uuzaji wa Solder wa Mikono:If manual soldering is necessary, use a temperature-controlled soldering iron. Apply heat to the PCB pad, not directly to the display pins, and limit contact time to prevent overheating.
• Cleaning:Use cleaning solvents compatible with the display's plastic material to avoid discoloration or degradation.
• Storage:Within the specified temperature range (-35°C to +85°C), store in a dry, anti-static environment to prevent moisture absorption (which may lead to "popcorn" phenomenon during reflow soldering) and electrostatic discharge damage.

7. Mazingatio ya Ubunifu wa Programu

7.1 Drive Circuit Design

Usanidi sahihi wa mzunguko wa kusukuma ni muhimu sana kwa utendaji na maisha ya huduma.

• Kikomo cha Sasa:It is essential to connect a current-limiting resistor in series with each common anode (for static driving) or use a constant current driver. The resistor value can be calculated using Ohm's Law: R = (Vcc - VF) / IF. For example, with Vcc at 5V, VF at 2.6V, and a desired IF of 10 mA: R = (5 - 2.6) / 0.01 = 240 Ω.
• Low Current Operation:The device's characteristic parameters are specified down to 1mA per segment. For ultra-low-power applications, driving at 1-2 mA provides sufficient visibility while minimizing power consumption.
• Multiplexing:For multi-digit displays, multiplexing is standard practice. This involves enabling the common anode of one digit at a time while presenting the segment data for that digit. The peak current rating (90 mA, 1/10 duty cycle) allows for higher pulse currents to compensate for the reduced duty cycle, thereby maintaining perceived brightness. The average current per segment must still adhere to the continuous current rating.
• Microcontroller Interface:Kwa onyesho la anode ya pamoja, pini za microcontroller zinazounganishwa na cathode za sehemu zinapaswa kusanidiwa kutoa ishara. Ili kuwasha sehemu, weka pini inayohusika kwenye kiwango cha chini. Ili kuzima, weka kwenye kiwango cha juu (au iwe na upinzani mkubwa ikiwezekana). Pini ya anode ya pamoja kwa kawaida huendeshwa na transistor ya nje (k.m. BJT ya PNP au MOSFET ya P-channel) inayoweza kutoa mkondo wa nambari nzima.

7.2 Thermal Management

Ingawa LED zina ufanisi, bado hutoa joto. Muundo lazima uzingatie kipengele cha kupunguza mkondo endelevu cha 0.33 mA/°C. Ikiwa onyesho linatarajiwa kufanya kazi katika mazingira ya joto la juu (k.m. ndani ya kifuniko kilichofungwa au karibu na vyanzo vingine vya joto), mkondo wa juu unaoruhusiwa unaendelea lazima upunguzwe ipasavyo. Ikiwa unaendeshwa karibu au kufikia mkondo wa juu uliokadiriwa, hakikisha uingizaji hewa wa kutosha au upotezaji joto.

8. Ulinganishi wa Kiufundi na Tofauti

The primary differentiation of LTD-5221AJF lies in its material technology and low-current optimization.

• Comparison with traditional GaAsP or GaP LEDs:Teknolojia ya AlInGaP inatoa ufanisi mkubwa wa kutolea mwanga na uthabiti bora wa joto, na hivyo kutoa maonyesho yenye mwangaza zaidi na rangi thabiti zaidi inayobadilika kidogo na joto na umri.
• Ikilinganisho na LED za mwangaza wa kawaida:Kifaa hiki kimechunguzwa na kuchaguliwa mahsusi kwa utendaji katika mikondo ya chini. Sehemu nyingi za kawaida za nambari saba zina sifa za 20mA; hiki kifaa kinahakikisha utendaji katika 1mA, na hivyo kuifanya bora zaidi katika matumizi yanayohitaji umeme wa betri kwa uangalifu.
• Ikilinganisha na vionyeshi vya LED ya bluu/kijani/njeupe:Rangi ya manjano-machungwa (605-611 nm) hutoa uonekano bora, na ikilinganishwa na rangi zenye mawimbi mafupi, kwa kawaida huchukuliwa kuwa na mzigo mdogo kwa macho chini ya hali ya mwanga dhaifu. Pia kwa ujumla huwa na ufanisi mkubwa wa mwanga ikilinganishwa na LED za zamani za bluu au nyeupe.

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

Swali: Je, naweza kuendesha kiolezi hiki moja kwa moja kutoka kwa pini ya kidhibiti 3.3V bila kutumia kipingamizi cha kudhibiti mkondo?
Jibu: Hapana. Lazima utumie kila wakati utaratibu wa kudhibiti mkondo (kipingamizi au kiendesha mkondo wa kudumu). Hata kama Vcc (3.3V) iko karibu na VF (2.05-2.6V), ukosefu wa kipingamizi kutawezesha mkondo mwingi kupita, unaoweza kuharibu LED na pini ya kidhibiti.

Swali: Kuna tofauti gani kati ya "Peak Emission Wavelength" na "Dominant Wavelength"?
A: Peak wavelength (λp=611nm) is the physical peak of the emission spectrum. Dominant wavelength (λd=605nm) is the wavelength of the pure monochromatic light that appears to the observer to have the same color as the LED. They are typically close but not identical.

Q: The matching ratio is 2:1. Does this mean one segment could be up to twice as bright as another?
A: Yes, this specification allows for that maximum difference under identical test conditions. For most applications, this difference is not perceptually significant. If extremely high uniformity is required, consult the manufacturer for tighter binning options or consider using displays from the same production lot.

Q: Can I use this display for outdoor applications?
A: The operating temperature range (-35°C to +85°C) supports many outdoor environments. However, direct exposure to sunlight and weather requires conformal coating on the PCB and a protective window for the display to prevent UV aging of plastics and moisture ingress. The high contrast of the light gray/white panel aids readability in sunlight.

10. Mifano Halisi ya Usanifu na Matumizi

10.1 Case Study: Portable Multimeter Display

In handheld digital multimeters, power efficiency is crucial. The LTD-5221AJF can be driven at 1-2 mA per segment in a multiplexed configuration. A microcontroller with integrated LED driver segments can efficiently control 2-4 digits. The wide viewing angle allows users to read measurements from different angles, and the high contrast ensures clear readability in both dim laboratory settings and brighter environments. The low forward voltage also helps maximize battery life when powered by 3V or 4.5V batteries.

10.2 Case Study: Industrial Timer/Counter

Kwa timu za viwango vya paneli, uimara na kuonekana ni muhimu. Uimara wa hali ngumu wa maonyesho ya LED unazidi teknolojia za zamani kama vile maonyesho ya mwanga wa utupu (VFD) kwa upinzani wa mshtuko/mshtuko na maisha. Utulivu wa nyenzo za AlInGaP unahakikisha rangi na mwangaza wa kiashiria haibadilika sana kwa miaka mingi ya uendeshaji endelevu. Usanidi wa anode ya pamoja unarahisisha kiunganishi na moduli za pato la dijiti za PLC za viwango ambazo kwa kawaida hutumia mpango wa ardhi ya pamoja.

11. Utangulizi wa Kanuni za Kiufundi

LTD-5221AJF inategemea teknolojia ya semikondukta ya AlInGaP inayokua kwenye msingi wa GaAs usio na uwazi. Mfumo huu wa nyenzo huruhusu kubuni kwa usahihi pengo la bendi la semikondukta kwa kurekebisha uwiano wa Al, In, Ga, na P. Pengo kubwa la bendi linahusiana na utoaji wa mwanga wa urefu mfupi wa wimbi (nishati ya juu). Muundo unaotumika hapa unaunda pengo la bendi ambalo, wakati elektroni zinapounganishwa na mashimo kwenye makutano ya PN chini ya upendeleo wa mbele, hutoa utoaji wa fotoni katika eneo la manjano-machungwa (takriban 611 nm).

"Msingi wa GaAs usio na uwazi" una umuhimu mkubwa. LED za nyekundu za mapema zilitumia msingi wa GaP wenye uwazi, lakini safu ya AlInGaP inalingana vizuri zaidi na kimiani na GaAs. Msingi wenyewe unachukua sehemu ya mwanga unaozalishwa, lakini katika vifaa vya hali ya juu, usanifu wa kisasa wa chip hutumia mbinu kama vile Kiotoaji cha Kutafakari cha Bragg Kilichosambazwa (DBR) au kuunganisha wafers kwenye msingi wenye uwazi (kama GaP) ili kuboresha ufanisi wa uchimbaji wa mwanga. Maelezo haya yanataja msingi usio na uwazi, ikionyesha kuwa huu ni usanifu wa kawaida na wa gharama nafuu wa chip.

12. Mwelekeo na Msingi wa Teknolojia

Ingawa maelezo maalum haya yanatoka mwaka 2000, teknolojia ya msingi ya AlInGaP bado ina umuhimu mkwa kwa LED nyekundu, ya machungwa na ya manjano kutokana na ufanisi na uthabiti wa rangi. Hata hivyo, uwanja mpana wa maonyesho umekua zaidi.

• Mwelekeo wa Ujumuishaji:Matumizi ya kisasa kwa kawaida hutumia maonyesho ya OLED yenye safu wima na mlalo au LCD ili kupata umbile kubwa katika kuonyesha maandishi na michoro. Hata hivyo, kwa matumizi rahisi ya kusoma nambari yenye mwanga mkali na gharama nafuu ambayo hayahitaji ubinafsishaji, LED yenye sehemu saba bado haina ushindani.
• Uboreshaji wa ufanisi:Utafiti endelevu wa nyenzo za AlInGaP na usanifu wa chip (kama vile usanifu wa chip uliopinduliwa nyembamba) unaendelea kusukuma ufanisi wa mwanga (lumeni kwa watt) juu zaidi, kuruhusu maonyesho makali zaidi kwa mkondo wa chini au kupunguza joto.
• Mchanganyiko wa rangi:For full-color applications, red AlInGaP LEDs are used in combination with indium gallium nitride (InGaN) blue and green LEDs. Yellow-orange variants like the LTD-5221AJF find their place in monochrome applications where their specific color and high efficiency are favored.
• Driver Integration:A modern trend is integrating the LED display with the driver IC in a single package or module, simplifying design and reducing component count, though potentially at a higher unit cost.

In summary, the LTD-5221AJF represents a mature, optimized solution for specific and enduring application needs: reliable, bright, low-power digital display.