LTS-4817CKS-P LED Digital Tube Datasheet - 0.39 Inch Character Height - AlInGaP Yellow Light - 2.6V Forward Voltage - 70mW Power Consumption - Technical Documentation

1. Product Overview

LTS-4817CKS-P is a high-performance, surface-mount, single-digit seven-segment display module. It is specifically designed for applications requiring clear and bright numeric readouts within a compact package. The device utilizes advanced AlInGaP (Aluminum Indium Gallium Phosphide) LED chip technology, grown on a GaAs substrate, renowned for its high efficiency and excellent color purity, particularly within the yellow spectrum. This display features a gray faceplate with white segments, providing high contrast for optimal readability. It is configured as a common anode device, a standard arrangement that simplifies driving circuitry in multi-digit applications, and includes a right-hand decimal point.

1.1 Main Features and Advantages

• Compact Size:Character height is 0.39 inches (10.0 mm), suitable for space-constrained applications.
• Excellent Optical Performance:Provides high brightness and high contrast, ensuring excellent character appearance even in well-lit environments.
• Wide Viewing Angle:Consistent visibility is provided across a wide range of viewing angles.
• Low Power Consumption:Designed for energy-efficient operation, with a typical forward current of 20mA per segment.
• Uniform segment illumination:Continuous, uniform segments ensure a clean and professional-looking digital display.
• High reliability:The solid-state structure provides a long service life and can resist impact and vibration.
• Quality Assurance:Devices are graded according to luminous intensity to ensure consistent brightness levels across different production batches.
• Environmental Compliance:Encapsulated as lead-free design, compliant with RoHS (Restriction of Hazardous Substances) directive.

1.2 Target Applications and Markets

Wannan na'urar dijital ta dace sosai da kowane nau'in na'urorin lantarki da ke buƙatar mai nuna lamba. Aikace-aikacen yau da kullun sun haɗa da ma'aunai na masana'antu (kamar ma'aunai na panel, na'urorin ƙidayar lokaci, ƙidayawa), na'urorin amfani da masu amfani (kamar microwave, injin wanki, na'urorin sauti), dashboard na mota (don nuna taimako), na'urorin kiwon lafiya da na'urorin aunawa da aunawa. SMD (Surface Mount Device) ɗin sa ya sa ya dace sosai da tsarin haɗawa ta atomatik, don haka yana rage farashin samarwa mai yawa da haɓaka amincin.

2. Technical Parameters and Objective Interpretation

Wannan sashe ya dogara da takamaiman takardun, don yin cikakken bincike na zahiri akan ƙayyadaddun lantarki da na gani na na'urar.

2.1 Absolute Maximum Ratings

These ratings define the stress limits that may cause permanent damage to the device. It is not recommended to reach or approach these limits during normal operation.

• Power consumption per segment:70 mW. This is the maximum power that a single LED segment can safely dissipate as heat.
• Peak forward current per segment:60 mA (a 1/10 duty cycle, 0.1ms pulse width). This rating applies only to pulse operation and should not be used for continuous DC drive.
• Continuous forward current per segment:25 mA at 25°C. When the ambient temperature exceeds 25°C, this current derates linearly at a rate of 0.28 mA/°C. For example, at 85°C, the maximum allowable continuous current is approximately: 25 mA - (0.28 mA/°C * (85°C - 25°C)) = 8.2 mA.
• Operating and storage temperature range:-35°C to +105°C. This device is suitable for industrial temperature range.
• Soldering Temperature:Withstands 260°C for 3 seconds at 1/16 inch (approximately 1.6mm) below the seating plane, which complies with lead-free reflow soldering process standards.

2.2 Electrical and Optical Characteristics (Typical at 25°C)

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

• Luminous Intensity (I_V):Light output is correlated with current. At a low current of 1mA, the typical intensity is 650 µcd (microcandelas). At the standard test current of 10mA, the intensity rises significantly to 8450 µcd. Designers must select the drive current based on the required brightness and power budget.
• Forward Voltage (V_F):At I_F=20mA, the typical value is 2.6V. This parameter is crucial for designing current-limiting circuits. The minimum value is 2.05V, indicating some variation exists between individual LEDs.
• Peak/Dominant Wavelength (λ_p/λ_d):588 nm (peak) and 587 nm (dominant wavelength). This confirms that the emitted light is located in the yellow region of the visible spectrum.
• Spectral Line Full Width at Half Maximum (Δλ):15 nm. This narrow bandwidth is characteristic of AlInGaP technology and contributes to achieving a pure color appearance.
• Reverse current (I_R):At V_R=5V, maximum 100 µA. This parameter is for test purposes only; applying continuous reverse bias is not a normal operating condition.
• Luminous intensity matching ratio:The maximum ratio between segments within the same device is 2:1. This means the dimmest segment is at least half as bright as the brightest segment, ensuring a uniform appearance.
• Crosstalk:≤ 2.5%. This specifies the maximum unintended light leakage into adjacent unlit segments, which is important for display clarity.

3. Grading System Description

Takaddar ta nuna cewa na'urar "ana rarrabe ta bisa ƙarfin haske". Wannan yana nufin tsarin rarrabawa, inda LED ke kasancewa bayan samarwa bisa ga fitowar haske (a cikin µcd) da aka auna a ƙayyadadden yanayin gwaji (watakila 10mA ko 20mA). Wannan yana tabbatar da cewa abokan ciniki suna samun sassa masu daidaitaccen matakin haske. Ko da yake wannan takaddar ba ta yi cikakken bayani kan takamaiman lambobin darajar ba, ya kamata masu zane su tuntubi masana'anta don sanin rarrabuwar ƙarfin da ake da shi, don tabbatar da daidaito a aikace-aikacensu, musamman lokacin amfani da na'urori masu lamba da yaya a jere.

4. Performance Curve Analysis

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

• I-V (Current-Voltage) Curve:Hana hana voltage ya mbele na uhusiano wa sasa ya mbele. Ni isiyo ya mstari, mara tu voltage ya mbele inapozidi kizingiti cha diode (takriban 2V kwa AlInGaP), sasa huongezeka kwa kasi.
• Nguvu ya mwanga dhidi ya sasa ya mbele:Mkunjo huu kwa kawaida ni wa mstari katika anuwai kubwa. Nguvu huongezeka sawia na sasa, hadi kufikia hatua ya usawa wa joto.
• Nguvu ya mwanga dhidi ya halijoto ya mazingira:Shows how light output decreases as junction temperature increases. AlInGaP LEDs exhibit a negative temperature coefficient, meaning brightness declines with rising temperature.
• Spectral Distribution:A chart showing relative light output across wavelengths, centered at 587-588 nm, with a specified 15 nm half-width.

Designers should use these curves to optimize driving conditions, understand thermal effects, and predict performance under different operating environments.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This device employs a surface-mount package. Key dimensional specifications in the datasheet include: all dimensions are in millimeters, with a general tolerance of ±0.25 mm. Specific quality control requirements for the display panel are: foreign matter on segments must be ≤10 mils, surface ink contamination ≤20 mils, bubbles within segments ≤10 mils, and reflector warpage ≤1% of its length. Plastic lead burrs are limited to a maximum of 0.14 mm. These specifications ensure consistency in physical appearance and reliable mounting.

5.2 Pin Connection and Polarity

Internal circuit diagram and pin connection table show the 7-segment display and decimal point are common anode configuration. The two common anode pins (pins 3 and 8) are internally connected. The cathodes for segments A to G and the decimal point (DP) are on separate pins (1, 2, 4, 5, 6, 7, 9, 10). Pin 5 is identified as the cathode for the right decimal point. Correct polarity identification is crucial for circuit design to avoid LED reverse bias.

5.3 Recommended Pad Pattern

A land pattern diagram is provided to guide PCB (Printed Circuit Board) design. Adhering to this recommended pattern, including proper pad dimensions, spacing, and thermal relief design, is essential for achieving reliable solder joints during reflow soldering and maintaining the mechanical integrity of the connections.

6. Soldering and Assembly Guide

6.1 SMT Soldering Instructions

The device is designed for reflow soldering. Key instructions include:

• Reflow profile:The maximum peak temperature is 260°C. The recommended preheat stage is 120-150°C, with a maximum duration of 120 seconds.
• Process Limitations:The number of reflow process cycles must be less than two. If a second soldering is required (e.g., for double-sided boards), it must be completely cooled to normal ambient temperature between the first and second soldering processes.
• Hand Soldering:If a soldering iron is used, the tip temperature should not exceed 300°C, and the contact time should be limited to a maximum of 3 seconds.

Following these guidelines prevents thermal damage to the LED chip, plastic package, and internal wire bonds.

6.2 Moisture Sensitivity and Storage

SMD digital tubes are transported in moisture-proof packaging. They must be stored at 30°C or below and a relative humidity (RH) of 60% or less. Once the sealed bag is opened, the components begin to absorb moisture from the atmosphere. If the parts are not used immediately and are not stored in a controlled dry environment (e.g., a dry cabinet), they must be baked before reflow soldering to prevent "popcorn" phenomenon or delamination caused by rapid expansion of moisture during the high-temperature reflow process. The datasheet provides specific baking conditions: components on reels are baked at 60°C for ≥48 hours, or bulk components are baked at 100°C for ≥4 hours / 125°C for ≥2 hours. Baking can only be performed once.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The device is supplied in embossed carrier tape wound on reels, suitable for automatic placement machines.

• Reel Dimensions:Standard 13-inch and 22-inch reel sizes are indicated.
• Carrier tape:Dimensions are provided and comply with the EIA-481-C standard. The carrier tape thickness is 0.40 ±0.05 mm.
• Packaging quantity:A 13-inch reel contains 800 pieces. A 22-inch reel contains a carrier tape 45.5 meters in length. The minimum packaging quantity for remaining lots is 200 pieces.
• Leader Tape and Trailer Tape:The carrier tape includes a leader tape (minimum 400 mm) and a trailer tape (minimum 40 mm) to facilitate machine loading.

7.2 Part Number and Revision

The base part number is LTS-4817CKS-P. The "-P" suffix may indicate a specific variant or packaging type. The datasheet itself has a revision history (Revision A, effective date January 11, 2020). Designers must always use the latest revision to ensure they have the most current specifications.

8. Application Notes and Design Considerations

8.1 Typical Application Circuit

For common anode digital tubes like the LTS-4817CKS-P, the anodes (pins 3 and 8) are connected to the positive supply voltage (V_CC). Each cathode pin (corresponding to segment A-G and DP) is connected to a current-limiting resistor, which is then connected to the output of the driver IC (e.g., decoder/driver or microcontroller GPIO pin). The driver sinks current to ground to illuminate the segment. The current-limiting resistor (R_LIMIT) value is calculated using Ohm's Law: R_LIMIT= (V_CC- V_F) / I_F, where V_Fis the forward voltage of the LED (using a typical value of 2.6V), I_FNi iwọn ina ti a nlo (fun apẹẹrẹ, 10mA tabi 20mA).

8.2 Design Considerations

• Gbigbe ina:Do not connect an LED directly to a voltage source without a current-limiting mechanism (resistor or constant current driver) to prevent thermal runaway and damage.
• Multiplexing:For multi-digit displays, multiplexing is typically used to control multiple segments with fewer driver pins. This involves rapidly cycling power to the common anode of each digit. The peak current rating of the LTS-4817CKS-P (60mA pulse) allows for higher instantaneous current during multiplexing to achieve the required average brightness.
• Thermal Management:Although the device itself has low power consumption, PCB layout should consider heat dissipation, especially when driving at higher currents or in high ambient temperatures. Sufficient copper area around the pads will help.
• ESD Protection:LEDs are sensitive to Electrostatic Discharge (ESD). Standard ESD handling precautions should be observed during assembly.

9. Technical Comparison and Differentiation

The LTS-4817CKS-P distinguishes itself by utilizing AlInGaP technology for yellow light emission. Compared to older technologies like GaAsP, AlInGaP offers significantly higher luminous efficiency, resulting in brighter output at the same drive current, better temperature stability, and superior color purity (narrower spectral width). Its SMD package and 0.39-inch character height give it an advantage over other SMD numeric displays, striking a balance between readability and saving board space. The inclusion of intensity grading is a key quality differentiator in applications requiring uniform appearance.

10. Frequently Asked Questions (FAQ)

Q1: What is the difference between peak wavelength (λ_p) and dominant wavelength (λ_d)?
A1: Peak wavelength is the wavelength at which the emission spectrum intensity reaches its maximum. Dominant wavelength is the wavelength of monochromatic light that matches the perceived color of the LED output. For narrow-spectrum LEDs like this one, they are very close (587nm vs 588nm).

Q2: Inaweza kuendesha LED hii kwa 25mA kwa mfululizo?
A2: Ndiyo, lakini tu ikiwa halijoto ya mazingira (T_a) ni sawa au chini ya 25°C. Katika halijoto ya juu ya mazingira, lazima upunguze mkondo kulingana na kipengele cha kupunguzwa cha 0.28 mA/°C ili kuepuka kuzidi halijoto ya juu ya kiungo na kupunguza uaminifu.

Q3: Kwa kuwa sifai kuifanya kinyume, kwa nini jaribio la mkondo wa kinyume ni muhimu?
A3: I_RTesting is a quality control measure. High reverse leakage current may indicate defects in the LED chip PN junction.

Q4: My assembly process requires two reflow soldering cycles. Is this allowed?
A4: Permitted, but strictly limited to a maximum of two times. You must ensure that the circuit board and components are completely cooled to room temperature between the first and second reflow cycles.

11. Practical Application Examples

Scenario: Design a simple digital timer display.
Wani mai zane yana ƙirƙira na'urar ƙidayar lokaci mai nuni da lambobi biyu don mintuna da dakika. Za su yi amfani da na'urori biyu na LTS-4817CKS-P. Anode gama-gari na kowace lambar za a haɗa shi da fil ɗin GPIO na microcontroller wanda aka saita a matsayin fitarwa, kowane shi kaɗai. Filayen cathode goma sha huɗu (sassan 7 + DP na kowace lamba) za a haɗa su tare a tsakanin lambobin biyu (ma'ana, duk sassan 'A' na cathode suna haɗuwa, duk sassan 'B' na cathode suna haɗuwa, da sauransu), kowanne an haɗa shi da resistor mai iyakancewar kwarara, sannan kuma zuwa filin GPIO ko wani IC mai tuƙi na waje wanda zai iya ɗaukar kwararar da ake buƙata. Microcontroller zai yi amfani da hanyar haɗawa ta rarraba lokaci: zai kunna anode na lambar 'mintuna', ya saita tsarin cathode na adadin mintunan da ake buƙata, ya jira ɗan gajeren lokaci (misali 5ms), sannan ya kashe wannan anode, ya kunna anode na lambar 'dakika', ya saita tsarin cathode na adadin dakika, ya jira, sannan ya maimaita. Wannan tsari yana faruwa da sauri fiye da yadda idon mutum zai iya gani, wanda ke haifar da hasashe cewa lambobin biyu suna haskakawa akai-akai. Ƙaramin maki na dama a kowace lamba za a iya amfani dashi azaman mai raba alama mai ƙyalli tsakanin mintuna da dakika.

12. Technical Principle Introduction

LTS-4817CKS-P ya dogara ne akan kayan semiconductor na AlInGaP da aka girma a kan wani abu mai ɗaukar hoto na Arsenide na Gallium (GaAs). Lokacin da ake amfani da ƙarfin lantarki mai kyau akan mahaɗin PN na wannan kayan, ana shigar da electrons da ramuka cikin yankin mai aiki, inda suke haɗuwa. Wannan tsarin haɗuwa yana sakin makamashi a cikin nau'in photon (haske). Takamaiman abun da ke cikin lattice na atom ɗin aluminum, indium, gallium, da phosphorus yana ƙayyade makamashin tazarar band, wanda kai tsaye yake ƙayyade tsawon zango (launi) na hasken da ake fitarwa. Ga wannan na'urar, an daidaita abun don samar da photons a cikin kewayon tsawon zango na rawaya (kimanin 587-588 nm). Sannan, an ɗora guntu a cikin ruwan tabarau na filastik da aka yi da gyare-gyare, wanda ke siffanta fitarwar haske kuma yana ba da kariyar muhalli.

13. Industry Trends and Development

The trend for display technologies like the LTS-4817CKS-P is the pursuit of higher efficiency, enabling brighter displays at lower power consumption, which is crucial for battery-powered devices. Simultaneously, there is a continuous push for miniaturization while maintaining or improving readability. Integration is another trend, where driving electronics are sometimes integrated into the display module itself to simplify system design. Furthermore, advancements in materials and packaging are improving the thermal performance and long-term reliability of LEDs, allowing them to be used in more demanding environments. While full-color, dot-matrix, and OLED displays continue to expand in high-end applications, monochrome digit LED displays like this remain highly relevant due to their simplicity, robustness, low cost, and excellent readability under various lighting conditions.