LTS-4801JS LED Digital Tube Datasheet - 0.39 Inch Character Height - Yellow - 2.6V Forward Voltage - 70mW Power Consumption - Technical Documentation

1. Product Overview

The LTS-4801JS is a compact, high-performance single-digit seven-segment display module, specifically designed for applications requiring clear numeric readouts. Its primary function is to visually display digits 0-9 and some letters through independently addressable LED segments. The device is designed for reliability and ease of integration into various electronic systems.

Its core technology utilizes AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor material to manufacture the LED chip, which is fabricated on a GaAs substrate. This material system is chosen for its exceptional efficiency in producing high-brightness yellow light. The display features a gray panel with white segment markings, providing excellent contrast and readability under various lighting conditions. The devices are classified according to luminous intensity, ensuring consistent brightness levels between batches.

2. Bincike mai zurfi na sigogi na fasaha

2.1 Halayen gani

Optical performance is the core of display functionality. Key parameters are measured under standardized test conditions (typically at an ambient temperature of 25°C).

• Luminous Intensity (I_V):This parameter defines the perceived brightness of a lit segment. At a forward current (I_F) of 1mA, the typical average luminous intensity is 867 μcd (microcandelas), with a minimum specified value of 320 μcd. Measurement is performed using a sensor and filter that simulate the human eye's photopic response curve (as defined by the CIE International Commission on Illumination).
• Peak Emission Wavelength (λ_p):The wavelength at which the LED emits its maximum optical power. For the LTS-4801JS, this value is typically 588 nanometers (nm), located in the yellow region of the visible spectrum.
• Dominant Wavelength (λ_d):Wannan darajar 587 nm ce, ita ce tsawon zango guda wanda idon mutum ya fahimta, wanda ya fi dacewa da launin hasken da ake fitarwa. Kusa da tsayin zango mafi girma da babban tsayin zango yana nuna cewa bakan haske yana da tsabta a launin rawaya.
• Ramin rabin faɗin layin bakan haske (Δλ):Ma'aunin aunawa shine 15 nm, wannan darajar tana nuna tsabtar bakan haske ko kuma yadda tsayin zangon hasken da ake fitarwa ya bazu a kusa da kololuwar. Ƙunƙarar rabin faɗi yawanci tana nufin mafi girman jikewa da tsabtar launi.
• Matsakaicin daidaiton ƙarfin haskakawa (I_V-m):Wannan rabo ya ƙayyade cewa bai wuce 2:1 ba, yana tabbatar da cewa bambancin haske tsakanin mafi duhun sashi da mafi haske na na'urar guda ɗaya bai wuce wannan ma'auni ba, don haka yana tabbatar da daidaiton bayyanar.

2.2 Halayen lantarki

Ma'auni na lantarki suna ayyana iyakokin aiki da sharuɗɗan aminci da amintaccen amfani.

• Forward voltage per segment (V_F):Voltage drop when the LED segment is conducting current. At a test current of 20mA, the typical forward voltage is 2.6V, with a minimum of 2.05V. This parameter is crucial for designing current limiting circuits.
• Continuous forward current per segment (I_F):At 25°C, the maximum DC current that can be continuously applied to a single segment is 25 mA. Above this temperature, the rating must be linearly derated at a rate of 0.33 mA per degree Celsius.
• Peak forward current per segment:For pulsed operation (1/10 duty cycle, 0.1ms pulse width), a higher peak current of 60 mA is allowed. This facilitates multiplexing schemes or brief overdrive to enhance perceived brightness.
• Reverse voltage per segment (V_R):The maximum voltage that can be applied in reverse across an LED segment without causing damage is 5V. Exceeding this value may lead to immediate or latent failure.
• Reverse current per segment (I_R):The leakage current when the maximum reverse voltage (5V) is applied is typically 100 μA or less.
• Power dissipation per segment (P_D):The maximum power that can be dissipated by a single segment is 70 mW. This value is calculated as V_F* I_F, which is a key parameter for thermal management.

2.3 Ƙimar zafi da muhalli

These ratings define the operational limits of the device in terms of temperature and soldering processes.

• Operating Temperature Range:This display is designed to operate reliably within an ambient temperature range of -35°C to +85°C.
• Storage Temperature Range:The device can be stored non-operational within the same temperature range of -35°C to +85°C.
• Soldering temperature:The device can withstand wave soldering or reflow soldering processes where the temperature 1/16 inch (approximately 1.6mm) below the mounting plane is maintained at 260°C for 3 seconds. This is the standard rating for lead-free soldering processes.

3. Grading and Classification System

The datasheet explicitly states the device is "classified by luminous intensity." This indicates a binning process exists, where manufactured units are sorted into different groups (bins) based on their light output measured at a standard test current (likely 1mA or 20mA). This ensures customers receive displays with consistent brightness levels. While this excerpt does not detail the specific bin codes, designers should note that brightness may vary between the minimum (320 μcd) and typical (867 μcd) values. For applications requiring strict brightness matching across multiple displays, specifying a bin may be necessary.

4. Performance Curve Analysis

The datasheet references "Typical Electrical/Optical Characteristic Curves" on the last page. Although specific graphs are not provided in the text, standard curves for such devices typically include:

• Relative Luminous Intensity vs. Forward Current (I-V Curve):This graph shows how light output increases with forward current, typically in a sublinear relationship, emphasizing the importance of current regulation over voltage regulation for maintaining consistent brightness.
• Forward Voltage vs. Forward Current:The graph illustrates the exponential I-V relationship of the diode.
• Relative Luminous Intensity vs. Ambient Temperature:It shows the decrease in light output as junction temperature rises, a key consideration for high-temperature or high-current applications.
• Spectral Distribution:A plot of relative intensity versus wavelength, showing a peak at approximately 588nm and a half-width of 15nm.

These curves are crucial for detailed design work, enabling engineers to predict performance under non-standard conditions.

5. Mechanical and Packaging Information

5.1 Physical Dimensions

This display has a character height of 0.39 inches (10.0 mm), referring to the physical size of a single numeric digit. The datasheet (page 2) provides a detailed dimensional drawing. Unless otherwise specified, all dimensions are in millimeters (mm), with a standard tolerance of ±0.25mm (0.01 inches). This drawing is crucial for PCB (Printed Circuit Board) layout to ensure correct package dimensions and aperture design.

5.2 Pin Configuration and Polarity

The LTS-4801JS is a 10-pin device, utilizing acommon anodeConfiguration. This means that the anodes (positive terminals) of all LED segments are internally connected together and brought out to a specific pin, while the cathode (negative terminal) of each segment has its own dedicated pin.

Pin Connection Details:

1. Pin 1: Cathode of Segment G
2. Pin 2: Cathode of Segment F
3. Pin 3: Common Anode (internally connected to Pin 8)
4. Pin 4: Cathode of Segment E
5. Pin 5: Cathode of Segment D
6. Pin 6: Cathode of Decimal Point (D.P.)
7. Pin 7: Cathode of Segment C
8. Pin 8: Common Anode (internally connected to Pin 3)
9. Pin 9: Cathode of Segment B
10. Pin 10: Cathode of Segment A

Gargadi Mai Muhimmanci:Fil 3 da 8 suna haɗe a ciki, suna ba da mahaɗin mahaɗi guda biyu don anode gama gari, wannan yana da amfani don zanen PCB ko ƙira na redundancy. Fil 6 an keɓe shi don maki goma na dama. Tsarin da'irar ciki yana tabbatar da wannan tsarin gama gari na anode a bayyane, yana nuna cewa duk anode na LED ɓangaren suna haɗuwa tare.

6. Soldering and Assembly Guide

Babban jagorar da aka bayar shine iyakar ƙimar zafin walda: Na'urar za ta iya jure 260°C a ƙasa da filin shigarwa na 1.6mm na tsawon dakika 3. Wannan ya dace da daidaitaccen lanƙwasin sake kunnawa maras gubar (IPC/JEDEC J-STD-020).

La'akari da Ƙira:

• Iyakancewar Kwarara:LED na'urori ne masu tuƙi ta hanyar kwarara. Kowane ɓangare dole ne ya kasance a jere tare da resistor mai iyakancewar kwarara (ko kuma a tuƙe shi da tushen kwarara mai dorewa) don hana wuce iyakar mafi girma na ci gaba da gaba (25mA). Ana ƙididdige ƙimar resistor ta amfani da dokar Ohm: R = (V_{Power Supply}- V_F) / I_F, where V_Fis the typical forward voltage (2.6V).
• Thermal Management:Ensure that the total power consumption (number of lit segments * V_F* I_F) does not cause overheating, especially when operating near the upper limit of the temperature range.
• ESD Protection:AlInGaP LED yana iya zama mai hankali ga zubar da wutar lantarki (ESD). Ya kamata a bi matakan kariya na yau da kullun na sarrafa ESD yayin haɗawa.
• Ajiya:Ajiye na'urar a cikin yanayin bushewa da kula da zafin jiki a cikin kewayon da aka kayyade na -35°C zuwa +85°C.

7. Application Recommendations

7.1 Typical Application Scenarios

LTS-4801JS ya dace da fadin aikace-aikace masu buƙatar lamba ɗaya mai iya karantawa sosai:

• Na'urorin Gwaji da Aunawa:Digital multimeters, frequency counters, power supplies, sensor readers.
• Consumer Electronics:Kitchen appliance timers, bathroom scales, audio equipment level meters.
• Industrial Control:Panel meters, process control indicators, timer displays.
• Automotive Aftermarket:Gauges and displays for performance monitoring (where environmental specifications apply).
• Prototyping & Educational Kits:Due to its simplicity and common-anode configuration, it is an excellent component for learning digital electronics and microcontroller interfacing.

7.2 Design Considerations and Interfaces

Microcontroller Interface:Driving a common anode display with a microcontroller typically involves:

1. Connecting the common anode pin to a positive voltage source (e.g., 3.3V or 5V) via a transistor, or directly if the MCU's GPIO can supply sufficient current for multiple segments.
2. Connecting the individual segment cathode pins to the microcontroller's GPIO pins, usually through current-limiting resistors.
3. To illuminate a segment, the corresponding MCU pin is driven low (sinking current) while the anode is held high.

Multiplexing:Although this is a single-digit display, the same principle applies when using multi-digit displays. Multiplexing involves rapidly cycling power between digits, illuminating only one digit at a time. This significantly reduces the number of required driver pins. The peak forward current rating (60mA) allows segments to be briefly driven harder during their multiplexed "on" time to compensate for the reduced duty cycle and maintain brightness.

Viewing Angle:The datasheet emphasizes a "wide viewing angle," which is highly beneficial for applications where the display might be viewed from off-axis positions.

8. Technical Comparison and Differentiation

The key differentiating factors of the LTS-4801JS lie in its material technology and specific performance characteristics:

• AlInGaP vs. Traditional Materials:Compared to older technologies like standard GaP (Gallium Phosphide) yellow LEDs, AlInGaP offers significantly higher luminous efficiency and brightness. This results in better readability, especially under high ambient light conditions, and potentially lower power consumption for a given light output.
• Color Quality:Ang tinukoy na 587-588nm pangunahing/peak wavelength ay gumagawa ng dalisay at puspos na dilaw, na karaniwang pinipili para sa mga indicator at display dahil sa mataas na visibility at mataas na contrast nito laban sa madilim na background.
• Grey Panel/White Segment:Ang kombinasyong ito ay nagbibigay ng mataas na contrast kapag naka-off ang display (puting karakter sa grey na background) at nagpapanatili ng mahusay na contrast kapag naka-on (maliwanag na dilaw na karakter sa grey na background), na nagpapahusay sa pangkalahatang readability kumpara sa mga display na may black panel o iba pang kombinasyon ng kulay.
• Pagiging Maasahan:Bilang isang solid-state device na walang gumagalaw na bahagi o marupok na filament, mayroon itong mataas na pagiging maasahan at mahabang buhay ng serbisyo sa ilalim ng tamang electrical at thermal na kondisyon.

9. Frequently Asked Questions (Based on Technical Parameters)

Q1: Ano ang layunin ng pagkakaroon ng dalawang common anode pin (3 at 8)?
A1: Suna a cikin ciki an haɗa su. Wannan yana ba da sassauci na ƙira don shimfidar PCB, yana ba da damar haɗin wutar lantarki daga kowane gefen kunsa. Hakanan yana taimakawa wajen rarraba ƙarfin lantarki idan ana turawa duk sassan a lokaci guda a ƙarfin lantarki mai girma.

Q2: Yadda ake ƙididdige daidaitaccen ƙimar resistor mai iyakancewar ƙarfin lantarki?
A2: Yi amfani da dabara R = (V_{Power Supply}- V_F) / I_F. Don wutar lantarki 5V, manufar ƙarfin lantarki na sashe 20mA, V_Fna yau da kullun shine 2.6V: R = (5 - 2.6) / 0.02 = 120 ohms. Don ƙira mai ra'ayin mazan jiya don guje wa ƙarfin lantarki mai yawa, koyaushe yi amfani da matsakaicin ƙarfin wutar lantarki da mafi ƙarancin V_F: R_min = (5 - 2.05) / 0.025 = 118 ohms. Madaidaicin resistor na 120Ω ko 150Ω ya dace.

Q3: Zan iya turawa wannan nuni kai tsaye ta hanyar filayen GPIO na microcontroller?
A3: It depends on the MCU. You can easily sink current (connect the cathode to a GPIO set low) because a typical MCU GPIO can sink 20-25mA. However, sourcing current to the common anode (setting the pin high) to light multiple segments may exceed a single pin's source current capability. Small NPN/PNP transistors or dedicated driver ICs (like the 74HC595 shift register with constant current output) are typically used to control the anode power supply.

Q4: What does "classified by luminous intensity" mean for my design?
A4: This means the displays are tested and binned according to brightness. If your application uses multiple displays and requires them to have the same brightness, you should specify that you need units from the same intensity bin. For a single display, it ensures the device you receive meets the minimum brightness specification.

10. Practical Design and Usage Examples

Scenario: Building a simple digital counter using Arduino.

1. Hardware Connections:Connect pins 3 and 8 (common anodes) to the Arduino's 5V pin via a 100Ω resistor (optional, for extra protection). Connect each cathode pin (1,2,4,5,6,7,9,10) to an Arduino digital pin (e.g., D2 to D9), each connection through a 150Ω current-limiting resistor.
2. Software Logic:In Arduino code, define the segments (A-G, DP) required to form each digit (0-9). This is typically stored in a byte array (segment mapping table). To display a digit, the code looks up the corresponding pattern, sets the Arduino pins connected to the desired segment cathodes to LOW (to light them), and sets other pins to HIGH. Since the anode is always at 5V, this completes the circuit for the selected segments.
3. Precautions:If all segments plus the decimal point are lit, the total current is approximately 9 segments * 20mA = 180mA, supplied by the 5V power rail. Ensure your power supply can handle this current.

11. Working Principle

The device operates based on the principle of electroluminescence in a semiconductor p-n junction. When the forward voltage applied across an LED segment exceeds the diode's threshold voltage (approximately 2.05V), electrons from the n-type AlInGaP layer recombine with holes from the p-type layer within the active region. This recombination event releases energy in the form of photons (light). The specific composition of the AlInGaP alloy determines the semiconductor's bandgap energy, which directly dictates the wavelength (color) of the emitted photons—in this case, yellow light at approximately 588nm. The seven segments (A through G) and the decimal point (DP) are independent LED chips that can be controlled independently by applying forward bias across their respective cathode-anode pathways.

12. Technology Trends and Background

AlInGaP technology represents a significant advancement in the performance of visible-light LEDs, particularly for red, orange, amber, and yellow light. Due to its superior efficiency and brightness, it has largely replaced older GaAsP and GaP technologies. Trends in display technology have shifted towards higher integration—such as multi-digit seven-segment modules, dot-matrix displays, and ultimately full-graphic OLED or TFT-LCD screens—which offer greater flexibility but often at increased complexity and cost. However, discrete seven-segment LEDs like the LTS-4801JS remain highly relevant in applications where cost, simplicity, reliability, extreme readability of individual digits, or high brightness under ambient light are critical. They persist as a foundational, robust solution in an increasingly complex world of display technologies.