LTC-571JD LED Digital Tube Datasheet - 0.56-Inch Character Height - AlInGaP Red Light - 2.6V Forward Voltage - 70mW Power Consumption - Technical Documentation

1. Product Overview

LTC-571JD ni moduli ya kuonyesha yenye utendaji wa hali ya juu, yenye tarakimu tatu na sehemu saba za LED, iliyoundwa mahsusi kwa matumizi yanayohitaji usomaji wa tarakimu ulio wazi na mkali. Kazi yake kuu ni kutoa pato la kuona la nambari katika vifaa vya elektroniki kama vile vifaa vya kupima, udhibiti wa viwanda, paneli za ala na vifaa vya matumizi ya kaya. Faida kuu ya kifaa hiki ni matumizi ya teknolojia ya chip ya LED ya kisasa ya AlInGaP (aluminium-indium-gallium-phosphide), ambayo ina ufanisi wa juu wa kutolea mwanga na usafi wa rangi ikilinganishwa na nyenzo za jadi. Hii inaleta sifa muhimu zilizokazwa katika maelezo ya mafunzo: mwangaza wa juu, muonekano bora wa herufi na sehemu zinazoendelea sawasawa, tofauti ya juu ya rangi, na pembe pana ya kuona. Kifaa hiki kimepangwa kulingana na nguvu ya mwanga, kuhakikisha uthabiti wa kiwango cha mwangaza kati ya vikundi tofauti vya uzalishaji, jambo muhimu sana kwa maonyesho ya tarakimu nyingi ambayo usawa ni muhimu. Soko lengwa linajumuisha wabunifu na wazalishaji wa vifaa vya elektroniki vya kitaalamu na viwanda, ambapo kuegemea, uwezo wa kusomeka chini ya hali mbalimbali za mwanga, na maisha marefu ya matumizi yanahitajika.

2. Detailed Technical Parameters

2.1 Luminous and Optical Characteristics

The optical performance is the core functionality of this display module. Under the test condition of a forward current (IF) of 1mA, its average luminous intensity (Iv) has a specified minimum of 340 µcd, a typical value of 700 µcd, with no upper maximum limit. This high brightness ensures visibility. The emitted light is in the red spectrum, with a peak emission wavelength (λp) of 656 nm and a dominant wavelength (λd) of 640 nm, both measured at IF=20mA. The spectral line half-width (Δλ) is 22 nm, indicating relatively pure color emission. It is important to note that the luminous intensity is measured using a sensor and filter combination that simulates the CIE photopic response curve, ensuring the measured values align with human visual perception.

2.2 Electrical Characteristics and Absolute Maximum Ratings

The electrical limits of the device define its safe operating area. Absolute maximum ratings must not be exceeded, as doing so will cause permanent damage. Key limitations include: a power dissipation of 70 mW per segment, a peak forward current of 110 mA per segment (under pulse conditions: 1/10 duty cycle, 0.1ms pulse width), and a continuous forward current of 25 mA per segment at 25°C, derating linearly by 0.33 mA/°C above 25°C. The maximum reverse voltage per segment is 5 V. The forward voltage (VF) per segment is typically 2.6V at IF=20mA, with a maximum of 2.6V, while the reverse current (IR) per segment is a maximum of 100 µA at VR=5V. The segment-to-segment luminous intensity matching ratio is specified as a maximum of 2:1, ensuring visual uniformity across the entire display.

2.3 Thermal and Environmental Specifications

Reliability across the temperature range is a key characteristic. The device is rated for an operating temperature range of -35°C to +85°C, with an identical storage temperature range. This wide range makes it suitable for harsh environments. For assembly, the maximum soldering temperature is 260°C for a maximum duration of 3 seconds, measured 1.6mm below the mounting plane. This is a standard guideline for wave soldering or reflow processes to avoid thermal damage to the LED chip or package.

3. Maelezo ya Mfumo wa Kugawa Daraja

Uhakiki-nyaraka unaelezea wazi kuwa kifaa hiki "kimegawanywa kulingana na nguvu ya mwanga." Hii inaonyesha kuwa kinatumia mfumo wa kugawa daraja au uchambuzi. Katika mchakato wa utengenezaji wa LED, kuna tofauti za asili za utendaji. Kugawa daraja kunamaanisha mchakato wa kugawa LED zilizotengenezwa katika vikundi (daraja) kulingana na vigezo maalum vya kipimo, kama vile nguvu ya mwanga, voltage ya mbele, au urefu wa wimbi kuu. Kwa LTC-571JD, kigezo kikuu cha kugawa daraja ni nguvu ya mwanga. Hii inahakikisha kuwa katika moduli ya kuonyesha ambayo mteja anapokea, viwango vya mwangaza vya tufe zote za nambari na sehemu zinafanana kwa karibu, na kuzuia hali ambapo nambari moja katika kitengo cha tufe nyingi za nambari inaonekana giza zaidi au nyangaza zaidi kuliko nyingine. Hii ni muhimu sana kwa usawa wa muonekano na utendaji wa bidhaa ya mwisho. Ingawa hakiki-nyaraka haujaelezea kwa kina msimbo maalum wa daraja au anuwai, kutaja kugawa daraja kunamhakikishia mtumiaji kuwa hatua hii ya udhibiti wa ubora ipo.

4. Uchambuzi wa Mkunjo wa Utendaji

Mwongozo wa maelezo una sehemu ya "Mikondo ya Kawaida ya Umeme/Optiki". Michoro hii ni muhimu kwa uchambuzi wa kina wa muundo. Ingawa maandishi yaliyotolewa hayajaelezea kwa kina mikondo maalum, mikondo ya kawaida ya vifaa kama hivi kwa kawaida inajumuisha:Mchoro wa uhusiano kati ya mkondo wa mbele na voltage ya mbele (Mchoro wa I-V):Mchoro huu unaonyesha uhusiano kati ya mkondo unaopita kwenye LED na kushuka kwa voltage kwenye ncha zake mbili. Sio mstari sawa, na wabunifu hutumia mchoro huu kuchagua upinzani unaofaa wa kudhibiti mkondo.Mchoro wa uhusiano kati ya nguvu ya mwanga na mkondo wa mbele (Mchoro wa L-I):Mchoro huu unaonyesha jinsi pato la mwanga linavyoongezeka kadri mkondo unavyoongezeka. Kwa kawaida ni laini ndani ya safu fulani, lakini hujaa kwenye mikondo ya juu.Mwonekano wa Uhusiano wa Nguvu ya Mwanga na Joto la Mazingira:Mkunjo huu unaonyesha jinsi pato la mwanga linavyopungua kadri joto la kiungo cha LED linavyopanda. Kuelewa kupunguzwa huku ni muhimu sana kwa usanidi unaoendeshwa katika mazingira yenye joto la juu.Mchoro wa Usambazaji wa Wigo:Mchoro wa Uhusiano wa Nguvu ya Jamaa na Urefu wa Wimba, unaonyesha umbo na usafi wa kilele cha mionzi nyekundu karibu na 640-656 nanometers.

5. Habari za Mitambo na Ufungaji

Usanifu wa mitambo unahakikisha usakinishaji na muunganisho wa umeme unaotegemewa. Kifaa hiki kinatumia ufungaji wa kawaida, na urefu wa herufi ni inchi 0.56 (milimita 14.2). Vipimo vya ufungaji vinatolewa katika michoro ya kina, na vipimo vyote viko kwa milimita, isipokuwa ikitajwa vinginevyo, na uvumilivu wa kawaida ni ±0.25 mm. Hii inarahisisha usanifu sahihi wa pedi za PCB (Bodi ya Mzunguko wa Kuchapishwa). Mchoro wa Muunganisho wa Pini ni muhimu kwa uunganishaji sahihi wa waya. LTC-571JD ni aina ya cathode ya pamoja ya multiplexed yenye nukta ya desimali upande wa kulia. Pini 12 zimegawiwa kama ifuatavyo: Pini 1: Anodi E, Pini 2: Anodi D, Pini 3: Anodi D.P. (nukta ya desimali), Pini 4: Anodi C, Pini 5: Anodi G, Pini 6: Hakuna Muunganisho, Pini 7: Anodi B, Pini 8: Cathode ya Pamoja ya Kidokezo 3, Pini 9: Cathode ya Pamoja ya Kidokezo 2, Pini 10: Anodi F, Pini 11: Anodi A, Pini 12: Cathode ya Pamoja ya Kidokezo 1. Mchoro wa mzunguko wa ndani unaonyesha kwamba kila sehemu ya kidokezo inashiriki muunganisho wa cathode ya pamoja, ambayo ni utaratibu wa kawaida wa vionyeshi vya multiplexed ili kupunguza idadi ya pini za kuendesha zinazohitajika.

6. Mwongozo wa Uchomelezaji na Usanikishaji

Proper handling is critical for reliability. The key guideline provided is the soldering temperature limit: a maximum of 260°C for 3 seconds, measured 1.6mm below the seating plane. This is compatible with standard lead-free reflow temperature profiles. Designers should ensure their PCB assembly process adheres to this limit to prevent thermal stress on the LED chip, which can lead to reduced light output, color shift, or catastrophic failure. For manual soldering, a temperature-controlled iron should be used, and contact time should be minimized. Prior to use, the device should be stored in its original moisture barrier bag and kept in a controlled environment (within the specified -35°C to +85°C range) to prevent moisture absorption, which can cause "popcorning" during reflow.

7. Habari za Ufungaji na Uagizaji

Sehemu namba ni LTC-571JD. Ingawa dondoo zilizotolewa hazijaorodhesha maelezo mahususi ya ufungashaji (mfano, ufungashaji wa mkanda, idadi ya mabomba), desturi ya kiwango cha tasnia kwa vionyeshi kama hivi ni kutumia mabomba ya kuzuia umeme statiki au vibao vya usafirishaji ili kulinda pini na paneli. "Namba ya vipimo" DS30-2001-188 na "Tarehe ya kuanza kutumika" 12 Juni 2001 ni vitambulisho vya udhibiti wa toleo. Kanuni ya kutaja aina "LTC-571JD" inaweza kufuata mfumo wa usimbuaji wa ndani ambapo "LTC" inaweza kumaanisha laini ya bidhaa za onyesho, "571" inabainisha ukubwa na aina, na "JD" inaweza kumaanisha rangi, kiwango au tofauti nyingine.

8. Mapendekezo ya Matumizi

8.1 Mandhari ya Kawaida ya Utumiaji

Kionyesha hiki kinafaa kabisa kwa kifaa chochote kinachohitaji usomaji wazi wa nambari zenye tarakimu nyingi. Matumizi ya kawaida ni pamoja na: multimeters za dijiti na clamp meters, frequency counters, process timers na controllers, vionyeshi vya moduli za umeme, vifaa vya ufuatiliaji wa matibabu, zana za utambuzi wa magari, na point-of-sale terminals. Mwangaza wake wa juu na pembe ya maono pana hufanya iwe inafaa kwa matumizi ambayo yanaweza kuhitaji kutazamwa kutoka pembe fulani au chini ya mwanga mkali wa mazingira.

8.2 Design Considerations and Circuit Implementation

Kubuni kwa kutumia LTC-571JD kunahitaji mzunguko wa kiendeshi cha multiplexing kwa sababu inatumia muundo wa cathode ya pamoja. Kawaida hutumia microcontroller au IC maalum ya kiendeshi cha kuonyesha (kama vile MAX7219 au vifaa sawa). Kiendeshi huwezesha kila cathode ya pamoja ya kisanduku cha nambari (pini 8, 9, 12) kwa mpangilio kwa mzunguko wa juu (mfano 100Hz-1kHz), wakati huo huo kutoa data inayolingana ya anode ya sehemu (pini 1, 2, 3, 4, 5, 7, 10, 11) kwa kisanduku hicho cha nambari. Njia hii inapunguza idadi ya pini za I/O zinazohitajika kutoka (sehemu 7 + nukta 1 ya desimali) * tarakimu 3 = 24 hadi sehemu 7 + nukta 1 ya desimali + tarakimu 3 = 11. Lazima upinzani wa kuzuia mkondo uwekwe kwa mfululizo kwenye kila mstari wa anode ya sehemu ili kuweka mkondo wa mbele (mfano, 10-20 mA kwa kila sehemu). Thamani ya upinzani inaweza kuhesabiwa kwa kutumia fomula R = (Vcc - Vf) / If, ambapo Vf ni voltage ya kawaida ya mbele (2.6V). Kwa usambazaji wa umeme wa 5V na lengo la mkondo wa 15mA: R = (5 - 2.6) / 0.015 = 160 ohms. Upinzani wa 150 au 180 ohms unafaa. Mabuni lazima wahakikishe kuwa mkondo wa kilele kwa kila sehemu hauzidi kiwango cha msukumo cha 110mA na kwamba matumizi ya wastani ya nguvu kwa kila sehemu, kwa kuzingatia uwiano wa wakati wa multiplexing, yanabaki chini ya 70mW.

9. Technical Comparison and Differentiation

The LTC-571JD is primarily differentiated by its use of AlInGaP LED technology. Compared to technologies like traditional standard GaAsP (Gallium Arsenide Phosphide) red LEDs, AlInGaP offers significantly higher luminous efficiency. This means it can produce more light output (higher brightness) at the same current, or achieve the same brightness at lower current, thereby improving energy efficiency. The designation "High-Efficiency Red" highlights this advantage. Furthermore, AlInGaP LEDs typically offer better temperature stability and longer operational life. The "Continuous Uniform Segment" feature indicates the use of a high-quality mask or diffuser design that eliminates gaps or uneven illumination within each segment, providing a professional, high-quality appearance superior to displays where segment or dot patterns are noticeable.

10. Maswali Yanayoulizwa Mara kwa Mara (FAQ)

Swali: Je, "No Connection" pini (pini 6) inatumika kwa nini?
Jibu: Pini hii ipo kwa mitambo, lakini imetengwa kwa umeme. Inaweza kujumuishwa ili kudumisha ulinganifu na uthabiti wa mitambo wakati wa mchakato wa kuingiza plastiki, au ili kudumisha umbali wa kawaida wa pini. Haipaswi kuunganishwa na mstari wowote wa mzunguko.

Swali: Katika usanidi wa multiplexing, jinsi ya kuhesabu mkondo wa wastani kwa kila sehemu?
A: The average current equals the peak current multiplied by the duty cycle. For a three-digit multiplexed display where each digit has equal time, the duty cycle per digit is 1/3. If each segment is driven at 20mA when its digit is active, the average current per segment is 20mA * (1/3) ≈ 6.67mA. This average current is used for power consumption calculations.

Q: Can I drive this display with a constant (non-multiplexed) current?
A: Technically yes, by connecting all common cathodes together and driving each segment anode independently. However, this would require 11 drive lines (8 anodes + 3 cathodes tied together) and is less efficient than multiplexing in terms of component count and microcontroller I/O usage. The electrical ratings still apply.

Q: What does "gray panel and white segments" mean?
Jibu: Hii inaelezea muonekano wa kionyeshi wakati haujawashwa. Panel (usuli) ni kijivu, ambacho husaidia kuongeza utofauti wakati namba nyekundu zinawaka. Namba zenyewe ni nyeupe, ambayo ni rangi ya nyenzo zilizosambazwa au kifuniko, mwanga wa LED nyekundu unapita kupitia hiyo, ukitoa mwanga mwekundu mkali wakati umeme unapowashwa.

11. Mifano ya Uundaji na Matumizi Halisi

Fikiria kubuni voltamita rahisi yenye tarakimu tatu kwa kutumia kontroller ndogo (microcontroller) yenye kibadilishaji cha analogi-kwa-digiti (ADC). Kontroller ndogo husoma voltage (0-5V), kuibadilisha kuwa tarakimu tatu (0.00 hadi 5.00), na kuendesha LTC-571JD. Msimbo wa kuendesha utatumia usambazaji wa wakati (time-division multiplexing). Katika kitanzi, itafanya: 1) Kuweka muundo wa namba kwa tarakimu ya mamia kwenye bandari ya anode, kisha kuwezesha cathode ya kisima cha namba 1 (pini 12). 2) Kusubiri mchepuko mfupi (mfano 2ms). 3) Kuzima kisima cha namba 1, kuweka muundo wa namba kwa tarakimu ya makumi, na kuwezesha cathode ya kisima cha namba 2 (pini 9). 4) Kurudia mchakato huu kwa tarakimu ya mwisho/desimali kwa kutumia kisima cha namba 3 (pini 8) na anode ya nukta ya desimali (pini 3). Kitanzi kinarudiwa haraka, kikitoa hisia ya tarakimu tatu zilizowaka kwa ustadi na kuendelea. Kwenye kila mstari wa anode, kupima upinzani unaozuia mkondo unaofaa kwa kiwango cha juu cha 15-20mA ni muhimu. Ubunifu huu unatumia vyema pini chache za I/O za kontroller ndogo.

12. Utangulizi wa Kanuni za Kiufundi

LTC-571JD is based on the principle of solid-state semiconductor light emission. The core component is an AlInGaP LED chip. When a forward voltage exceeding the diode junction potential (approximately 2.1-2.6V) is applied, electrons and holes recombine in the semiconductor active region, releasing energy in the form of photons (light). The specific composition of the AlInGaP alloy determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, red light (approximately 640-656 nanometers). The chip is mounted on an opaque GaAs substrate, which helps reflect light outward, improving efficiency. Light from the tiny LED chip passes through the molded plastic package, with the segment areas made of white diffusive material and the background area of a gray filter, thereby forming the recognizable seven-segment digit shape. The common-cathode multiplexing architecture is an electrical design choice that connects all LEDs of one digit to a shared negative terminal, allowing for individual digit control.

13. Technology Trends and Development

While LTC-571JD represents a mature and reliable technology, the broader field of display technology continues to evolve. The development trend for seven-segment displays is towards higher efficiency and integration. Modern variants may use more advanced semiconductor materials or chip-scale packaging for slightly better performance or narrower bezels. However, the basic multiplexed LED segment display remains highly relevant due to its simplicity, robustness, low cost for purely numeric output, and excellent visibility. The core principles embodied in this datasheet—efficient materials (AlInGaP), careful binning for uniformity, and clear mechanical/electrical specifications—remain foundational to the design of reliable display components. For new designs, engineers might also evaluate fully integrated modules with built-in controllers, or consider dot-matrix OLEDs for alphanumeric flexibility, but for purely numeric applications requiring high brightness and long life, displays like the LTC-571JD remain a proven, optimal solution.