LTD-5723AJF LED Digital Tube Datasheet - 0.56 Inch Character Height - Yellow Orange - 2.6V Forward Voltage - 70mW Power Consumption - Technical Documentation

1. Product Overview

LTD-5723AJF shine babban aiki, mai nuni biyu, na'urar nuni ta LED mai sassa bakwai. Babban aikinsa shine samar da bayanai masu haske da haske na lambobi da ƙayyadaddun haruffa a cikin na'urorin lantarki. Babban fasahar sa ta dogara ne akan kayan semiconductor na Aluminum Indium Gallium Phosphide (AlInGaP), wanda aka ƙera musamman don fitar da hasken launin rawaya-orange. Zaɓin wannan kayan shine mabuɗin don cimma babban haske da inganci na na'urar. Mai nuni yana amfani da launin fuska mai launin toka da farar sifofin sassa, wanda ke haɓaka bambanci da karantawa a cikin yanayi daban-daban na haske. An rarraba shi bisa ƙarfin haske, yana tabbatar da daidaiton matakan haske tsakanin nau'ikan samarwa daban-daban. An ƙera na'urar a matsayin nau'in cathode gama gari, wanda shine daidaitaccen tsari don sauƙaƙe da'irori masu tuƙi na masu nuni da yawa.

2. In-depth Interpretation of Technical Parameters

2.1 Photometric and Optical Characteristics

Optical performance is the core of this display's functionality. At a forward current (IF) of 1mA, the average luminous intensity (Iv) is specified as a minimum of 320 µcd, with a typical value of 900 µcd. This parameter represents the amount of visible light emitted and is crucial for determining display visibility. The dominant wavelength (λd) is 605 nm, and at IF=20mA, the peak emission wavelength (λp) is 611 nm, which clearly positions the output in the yellow-orange region of the visible spectrum. The spectral line half-width (Δλ) is 17 nm, describing the purity or narrowness of the emitted color; a smaller value indicates better monochromaticity of the light source. Luminous intensity matching between segments is guaranteed within a 2:1 ratio, ensuring uniform appearance of all lit segments of a character.

2.2 Electrical Parameters

Electrical specifications define the operating boundaries and conditions for reliable use. Absolute maximum ratings set hard limits: continuous forward current per segment is 25 mA (derated linearly at 0.33 mA/°C from 25°C), peak forward current under pulse conditions is 60 mA, and maximum reverse voltage per segment is 5 V. At IF=20mA, the typical forward voltage (VF) per segment is 2.6 V, with a minimum of 2.05 V. This forward voltage is a key parameter for designing current-limiting circuits. At VR=5V, the maximum reverse current (IR) is 100 µA, indicating the leakage level when the LED is reverse-biased. The power dissipation limit per segment is 70 mW, which impacts thermal design.

2.3 Thermal and Environmental Specifications

The operating temperature range of this device is -35°C to +85°C, with the same storage temperature range. This wide range makes it suitable for challenging environments from industrial control to automotive interiors. The soldering temperature specification is critical for assembly: the device can withstand 260°C for 3 seconds at a point 1/16 inch (approximately 1.6 mm) below the mounting plane. Adherence to this reflow temperature profile is essential to prevent damage to the internal semiconductor die and wire bonds during surface-mount assembly.

3. Binning System Description

The datasheet explicitly states that the device is "binned for luminous intensity." This indicates that a binning or sorting process is implemented after production. The LEDs are tested and grouped (binned) based on their measured light output at a standard test current (likely 1mA or 20mA according to the datasheet). This ensures customers receive displays with consistent and predictable brightness levels. While the specific binning code structure is not detailed in this excerpt, such systems typically use alphanumeric codes to denote predefined ranges of luminous intensity, forward voltage, and sometimes wavelength. Designers must consult the manufacturer's complete binning documentation to select the appropriate grade based on their application's requirements for brightness uniformity.

4. Performance Curve Analysis

The datasheet references "typical electrical/optical characteristic curves," which are crucial for in-depth design analysis. Although specific graphs are not provided in the text, standard curves for such devices typically include:

• Luminous Intensity vs. Forward Current curve (I-V curve):This graph shows how light output increases with current. It is typically nonlinear; at very high currents, efficiency (lumens per watt) tends to decrease due to thermal effects.
• Forward voltage versus forward current curve:This graph shows the I-V characteristics of a diode, which is crucial for selecting the correct series resistor or designing a constant current driver.
• Curve of Luminous Intensity vs. Ambient Temperature:This curve illustrates how brightness decreases as junction temperature increases. Understanding this derating is crucial for applications operating in high-temperature environments.
• Spectral Distribution Diagram:Grafik hubungan intensitas relatif terhadap panjang gelombang, menunjukkan puncak pada 611 nm dan lebar setengah tinggi 17 nm, mengonfirmasi karakteristik warna.

Kurva-kurva ini memungkinkan insinyur untuk mengoptimalkan kondisi penggerak guna menyeimbangkan kecerahan, efisiensi, dan umur pakai.

Informasi Mekanik dan Kemasan

Perangkat dilengkapi dengan gambar dimensi kemasan rinci (tidak sepenuhnya disajikan dalam teks). Fitur mekanis kunci dari kemasan semacam ini (disimpulkan dan standar) meliputi: tinggi karakter 0,56 inci (14,22 mm), yang mendefinisikan ukuran karakter. Kemasan memiliki konfigurasi dua digit berdampingan, terintegrasi dalam satu housing. Ia memiliki 18 pin untuk koneksi listrik, menggunakan bentuk kemasan DIP (Dual In-line Package) standar atau serupa. Anotasi "Rt. Hand Decimal" dalam deskripsi bagian menunjukkan setiap digit menyertakan satu titik desimal di sisi kanan. Warna panel abu-abu dan segmen kode putih adalah bagian dari desain kemasan yang bertujuan meningkatkan kontras. Dimensi tepat, jarak pin, dan kontur kemasan keseluruhan tercakup dalam gambar dimensi, dengan toleransi ±0,25 mm kecuali dinyatakan lain.

Takaddar ta ambaci "lakatuttukan halaye na lantarki/na gani na yau da kullun", waɗanda ke da mahimmanci ga zurfin binciken ƙira. Ko da yake ba a ba da takamaiman jadawali a cikin rubutun ba, daidaitattun lakatuttukan irin waɗannan na'urori yawanci sun haɗa da:

A pin connection table is provided. It details the 18-pin configuration, where pins 1-12 and 15-18 are the anodes for specific segments (A-G and DP) of Digit 1 and Digit 2, respectively. Pins 13 and 14 are the common cathodes for Digit 2 and Digit 1, respectively. This common-cathode architecture means all LED segments for a single digit share a common ground (cathode) connection. The internal circuit diagram (referenced but not shown) would illustrate how the 14 segments (7 per digit, plus the decimal point) are connected to these anode and cathode pins. This structure allows for time-division multiplexing, where digits are illuminated rapidly one after another by toggling their common cathodes, thereby reducing the total number of driver pins required.

7. Welding and Assembly Guide

The primary assembly guideline provided is the soldering temperature specification: 260°C for 3 seconds at 1/16 inch (approximately 1.6mm) below the mounting plane. This is the standard reflow temperature profile for many lead-free soldering processes. Key considerations include:

• Reflow temperature profile:Engineers must ensure the oven temperature profile does not exceed this temperature/time at the component body to prevent damage to the epoxy package and the internal die.
• ESD Protection:Although not stated, AlInGaP LEDs are semiconductor devices and should be handled following standard ESD (Electrostatic Discharge) precautions.
• Cleaning:If cleaning is required after soldering, please use a method compatible with the display's epoxy resin material.
• Storage:Store within the specified range of -35°C to +85°C in a dry, anti-static environment to prevent moisture absorption and performance degradation.

8. Application Suggestions

8.1 Typical Application Scenarios

This display is ideal for applications requiring clear, medium-sized numeric readouts. Common uses include: test and measurement equipment (multimeters, oscilloscopes), industrial control panels, point-of-sale terminals, automotive dashboard displays (for non-critical information), consumer appliances (microwave ovens, ovens, audio equipment), and medical devices. The yellow-orange color is often chosen for its high visibility and lower perceived glare compared to pure red or green, especially under varying lighting conditions.

Higher Brightness and Efficiency: The AlInGaP material system converts electrical energy into light with significantly higher efficiency in the red, orange, and yellow spectral ranges, resulting in higher luminous intensity at the same drive current. Better Temperature Stability: Compared to older technologies, the variation in light output and wavelength of AlInGaP LEDs with temperature is typically smaller. Color Saturation: A spectral full width at half maximum (FWHM) of 17 nm indicates relatively pure color, making it more visually appealing and distinguishable than emitters with a broader spectrum. Contrast Ratio: The combined design of a gray panel with white segments aims to maximize contrast when the segments are off, improving overall readability compared to displays with black panels or segments of different colors.

• Drive Circuit:Use a constant current driver or appropriate current limiting resistor for each anode line. Calculate the resistor value based on the supply voltage (Vcc), typical forward voltage (Vf ~2.6V), and the desired forward current (e.g., 10-20 mA for good brightness).
• Time Division Multiplexing:对于像这样的多位数码管，时分复用驱动方案是高效的。这涉及通过晶体管开关依次使能每个数字的公共阴极，同时在阳极线上呈现该数字的段码数据。刷新率必须足够高（>60 Hz）以避免可见闪烁。
• Viewing Angle:The datasheet claims a "wide viewing angle," but for optimal placement, consider the angle of the primary user's line of sight relative to the display surface.
• Brightness Control:Brightness can be adjusted by changing the forward current (within specified limits) or by using Pulse Width Modulation (PWM) on the drive current.

9. Technical Comparison and Differentiation

The key differentiating advantage of the LTD-5723AJF stems from the comparison of its AlInGaP technology with older technologies, such as standard GaAsP (Gallium Arsenide Phosphide) LEDs:

• Higher Brightness and Efficiency:The AlInGaP material system converts electrical energy into light with significantly higher efficiency in the red, orange, and yellow spectral ranges, resulting in higher luminous intensity at the same drive current.
• Better Temperature Stability:Compared to older technologies, AlInGaP LEDs typically exhibit smaller fluctuations in luminous output and wavelength with temperature changes.
• Color saturation:A spectral full width at half maximum of 17 nm indicates relatively pure color, making it more visually appealing and distinguishable than emitters with broader spectra.
• Contrast:The combination design of a gray panel with white segments aims to maximize contrast when the segments are off, improving overall readability compared to displays with black panels or segments of different colors.

10. Frequently Asked Questions Based on Technical Parameters

Q: What is the purpose of the "Luminous Intensity Matching Ratio" being 2:1?
A: This ensures that under the same conditions, the brightness of the darkest segment in a character is not less than half the brightness of the brightest segment. This guarantees visual uniformity, preventing some segments from appearing significantly darker than others, which is crucial for readability.

Q: Can I drive this display with a 5V power supply?
A: Yes, but a current-limiting resistor must be connected in series with each anode. For example, to achieve a typical IF of 20mA with a 5V supply and a VF of 2.6V, the resistor value should be R = (5V - 2.6V) / 0.02A = 120 ohms. Also, be sure to verify the power dissipation on the resistor.

Q: What does "common cathode" mean for my circuit design?
A: This means the cathodes (negative terminals) of all LEDs for a digit are internally connected to one pin (pin 14 for digit 1, pin 13 for digit 2). To illuminate a digit, you need to apply a positive voltage to the anodes of the desired segments while connecting that digit's common cathode pin to ground (0V). This simplifies time-division multiplexing.

Q: How should I understand the "Peak Forward Current" rating of 60mA?
A: Wannan shine mafi girman kwararar wucin gadi da LED zata iya jurewa a ƙarƙashin yanayin bugun jini na ɗan gajeren lokaci (0.1ms faɗin bugun, 1/10 cikakken aiki). Ba ya dacewa da aiki na ci gaba ba. Wucewa madaidaicin kwararar gaba (25 mA) na iya haifar da lalacewa cikin sauri ko kasa aiki.

The key differentiating advantages of LTD-5723AJF stem from the comparison of its AlInGaP technology with older technologies, such as standard GaAsP (Gallium Arsenide Phosphide) LEDs:

Yi la'akari da ƙirƙirar ƙididdiga mai sauƙi na lambobi biyu ta amfani da microcontroller. Fil ɗin I/O na microcontroller za a haɗa shi ta hanyar resistor mai iyakance kwarara zuwa layukan anode goma sha biyu (sassan lambobi biyu A-G da DP). Ƙarin fil ɗin microcontroller guda biyu za su sarrafa transistor ɗin NPN, wanda tarawar sa ke haɗe zuwa fil ɗin cathode gama gari (13 da 14), mai fitarwa kuma ya kasa ƙasa. Software zai aiwatar da tsarin aiki na raba lokaci: kashe transistor ɗin cathode biyu, saita fil ɗin I/O don nuna sassan "Lambar 1", sannan a buɗe transistor ɗin cathode na Lamba 1 na ɗan gajeren lokaci. Sannan a maimaita wannan tsari don Lamba 2. Wannan madauki yana gudana akai-akai tare da mitar girma. Matsakaicin kwararar kowane yanki yana ƙaddara ta hanyar kololuwar kwarara da cikakken aiki (misali, kowane lamba 20mA kololuwa, 50% cikakken aiki, matsakaicin kwarara 10mA). Wannan hanyar tana rage adadin abubuwan da ake amfani da su da kuma amfani da wutar lantarki.

Color Saturation: A spectral full width at half maximum (FWHM) of 17 nm indicates relatively pure color, making it more visually appealing and distinguishable than emitters with broader spectra.

Its working principle is based on the electroluminescence of a semiconductor p-n junction. The AlInGaP (aluminum indium gallium phosphide) crystal structure forms the active region. When a forward voltage exceeding the diode's turn-on voltage (approximately 2.0-2.2V) is applied, electrons from the n-type region and holes from the p-type region are injected into the active region. When these carriers recombine, they release energy. In AlInGaP, a significant portion of this energy is released as photons (light) with a wavelength corresponding to the material's bandgap energy, which is designed to be approximately 605-611 nm (yellow-orange). The opaque GaAs substrate helps reflect light upward, improving external light extraction efficiency. Each segment of the 7-segment display contains one or more of these tiny AlInGaP LED chips.

13. Development Trends

Although this specific device represents mature technology, the broader field of display LEDs continues to evolve. Trends related to such indicator lights and segment displays include:

• Efficiency Improvement:Ongoing materials science research aims to enhance internal quantum efficiency (generating more photons per electron) and light extraction efficiency (more photons escaping the chip), enabling brighter displays at lower power consumption.
• Miniaturization:Even in segment code displays, there is a continuous pursuit of smaller pixel pitch and higher resolution, allowing more information to be displayed in the same space.
• Integration:Trends include integrating the LED driver IC directly into the display package or module, simplifying circuit design for end users.
• New Materials:Although AlInGaP dominates the red-orange-yellow spectrum, other material systems like InGaN (used for blue/green/white light) are also advancing. The trend is toward achieving full-color capability in small displays.
• Flexible Substrates:Research on placing LED chips on flexible circuits may lead to novel display form factors, though this is more applicable to dot-matrix displays than traditional segment displays.

LTD-5723AJF, leveraging its mature AlInGaP technology, delivers a reliable and high-performance solution for applications requiring its specific color, brightness, and dimensional characteristics.