LTS-5825CKG-PST1 LED Digital Tube Datasheet - 0.56 Inch Character Height - AlInGaP Green Light - 2.6V Forward Voltage - 25mA Continuous Current - Technical Documentation

1. Product Overview

LTS-5825CKG-PST1 na'urar LED ce mai girma guda ɗaya, mai haɓaka aiki, mai haɗawa ta saman (SMD), wacce aka tsara don aikace-aikacen da ke buƙatar karatun lambobi masu haske da bayyananne. Babban fasahar ta ta dogara ne akan kayan semiconductor na AlInGaP, waɗanda aka girma akan tushen GaAs marar gani. Wannan tsarin kayan yana da suna wajen samar da haske mai inganci na kore. Ana amfani da abin rufe fuska baƙi don haɓaka bambanci, kuma ana amfani da sassan farare don mafi kyawun watsa haske da gani. Tsawon harafinsa shine inci 0.56 (mm 14.22), yana da kyakkyawan bayyanar haruffa, wanda ya dace da na'urorin lantarki na masu amfani da na masana'antu waɗanda ke da iyakataccen sarari amma karantawa tana da mahimmanci.

1.1 Core Advantages and Target Market

This seven-segment display is designed for reliability and performance. Key advantages include low power consumption, high brightness output, and a wide viewing angle, ensuring clear readability from various positions. The solid-state construction provides inherent reliability and a long operational life. Products are graded by luminous intensity to ensure consistent brightness matching in multi-digit applications. Primary target markets include instrument panels, test and measurement equipment, point-of-sale terminals, industrial control systems, and automotive dashboard displays—applications requiring single, highly visible digits.

2. In-depth and Objective Interpretation of Technical Parameters

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. The maximum power dissipation per segment is 70 mW. The peak forward current rating per segment is 60 mA, but this is only permitted under pulsed conditions (1 kHz frequency, 10% duty cycle) to manage heat. The continuous forward current per segment is the safe limit for steady-state operation, which is 25 mA at an ambient temperature (Ta) of 25°C. This rating derates linearly by 0.28 mA per degree Celsius when the ambient temperature exceeds 25°C. The device can operate and be stored within a temperature range of -40°C to +105°C. Soldering conditions specify that during reflow soldering with a peak temperature of 260°C for 3 seconds, the device body should be at least 1/16 inch above the mounting plane.

2.2 Electrical and Optical Characteristics

These parameters are measured under standard test conditions Ta = 25°C, providing expected performance indicators. At a forward current (IF) of 1 mA, the luminous intensity (Iv) ranges from a minimum of 501 μcd to a typical value of 1700 μcd. The peak emission wavelength (λp) is 571 nm, and the dominant wavelength (λd) at IF=20mA is 572 nm, clearly belonging to the green light spectrum. The spectral line half-width (Δλ) is 15 nm, indicating relatively pure color. The forward voltage per segment (VF) at IF=20mA is a maximum of 2.6V, with a typical value of 2.05V. The reverse current (IR) at a reverse voltage (VR) of 5V is a maximum of 100 μA, but continuous operation under reverse bias is prohibited. The segment-to-segment luminous intensity matching ratio is specified as a maximum of 2:1, ensuring uniform brightness across the entire digit.

3. Mechanical and Packaging Information

3.1 Package Dimensions and Structure

The device is in a surface-mount package. Key dimensional tolerance is ±0.25mm unless otherwise specified. Structural details include specifications for plastic flash (max 0.14 mm) and PCB warpage (max 0.06 mm). Pad surface finish is critical for reliable soldering, employing a layered structure: at least 1200 microinches of copper, at least 150 microinches of nickel, and 4 microinches of gold plating. An additional coating of 400 microinches is also applied.

3.2 Pin Connections and Internal Circuitry

The digital tube adopts a 10-pin configuration and uses a common anode circuit design. The internal circuit diagram shows that the anodes of all segments are internally connected to two common anode pins (pin 3 and pin 8). Each segment's cathode (A, B, C, D, E, F, G, and the decimal point DP) has its dedicated pin. This configuration is commonly used in multiplexing applications where multiple digital tubes share driving lines.

4. Soldering and Assembly Guide

4.1 SMT Welding Instructions

For reflow soldering, a specific temperature profile must be followed. The preheating phase should be between 120-150°C, for a maximum of 120 seconds. The peak temperature during reflow must not exceed 260°C, and the time above this critical temperature should be limited to a maximum of 5 seconds. Crucially, the number of reflow process cycles must be less than two. If a second reflow is required (e.g., for double-sided assembly), the board must be allowed to cool completely to normal ambient temperature between the first and second processes. For manual soldering using a soldering iron, the tip temperature should not exceed 300°C, and the contact time per solder joint should be limited to a maximum of 3 seconds.

4.2 Recommended Solder Pad Pattern

Recommended land pattern (package outline drawing) is provided with dimensions in millimeters. Following this pattern is critical for forming good solder joints, ensuring mechanical stability, and providing thermal relief during operation.

5. Packaging and Handling

5.1 Packaging Specifications

The devices are supplied in tape-and-reel format for automated assembly. The carrier tape is made of black conductive polystyrene alloy with a thickness of 0.30±0.05 mm. The warpage of the carrier tape is controlled to not exceed 1 mm over a length of 250 mm. Each 13-inch reel contains 700 devices, and the total tape length on a 22-inch reel is 44.5 meters. The packaging includes leader and trailer sections (at least 400 mm and 40 mm, respectively) to facilitate machine feeding. For remaining lots, a minimum packaging quantity of 200 pieces is specified. The direction for pulling the carrier tape from the reel is clearly marked.

5.2 Moisture Sensitivity and Baking

As a surface-mount device, this digital tube is sensitive to moisture absorption, which may lead to "popcorn" phenomenon or delamination during high-temperature reflow. The device is shipped in sealed moisture-proof packaging and should be stored under conditions of ≤30°C and relative humidity ≤90%. Once the sealed bag is opened, the device has a limited floor life. If the bag is opened for more than one week under conditions that do not meet the storage specifications (temperature below 30°C and relative humidity below 60%), baking is required before reflow. Baking conditions depend on the packaging state: devices in reels need to be baked at 60°C for ≥48 hours; bulk devices need to be baked at 100°C for ≥4 hours or at 125°C for ≥2 hours. Baking should be performed only once.

6. Application Recommendations and Design Considerations

6.1 Yanar Farko Aikace-aikace

This seven-segment display is ideal for any application requiring a single, highly readable digit. Common uses include digital clocks (displaying seconds or minutes), battery level indicators, single-digit counters, parameter setting displays on appliances, and status code displays on electronic devices. Its SMD format makes it suitable for modern, compact PCB designs.

6.2 Zane-zane Tunani

• Current Limiting:A current limiting resistor must be connected in series with each segment cathode. The resistor value should be calculated based on the power supply voltage, the LED's forward voltage (VF), and the desired forward current (IF). The continuous forward current must not exceed 25 mA.
• Drive Circuit:Common anode configuration simplifies driving, allowing the use of low-side switches (transistors or ICs) to sink current from the cathode.
• Thermal Management:Ensure sufficient PCB copper area or thermal vias, especially when operating near maximum current or in high ambient temperatures, to prevent overheating and lumen depreciation.
• ESD Protection:As with all semiconductor devices, implement standard ESD precautions during handling and assembly.

7. Performance Curve Analysis

The datasheet references typical characteristic curves, which are crucial for detailed design. Although specific graphs are not detailed in the provided text, engineers typically expect to see forward current versus forward voltage (IV curve), luminous intensity versus forward current, luminous intensity versus ambient temperature, and possibly spectral distribution graphs. These curves enable designers to understand nonlinear behaviors, such as how efficiency changes with current or how brightness decreases with rising temperature, allowing optimization of driving conditions for specific application environments.

8. Technical Comparison and Differentiation

The key differentiation of the LTS-5825CKG-PST1 lies in its use of AlInGaP technology to produce green light. Compared to older technologies like traditional GaP, AlInGaP offers significantly higher luminous efficiency and brightness. The black mask/white segment design provides superior contrast, especially under bright lighting conditions, outperforming displays with light-colored masks. The 0.56-inch character height fills a specific niche between small indicator lights and large panel displays. Its luminous intensity grading is a quality assurance feature that ensures consistency in multi-digit applications, a critical factor not always guaranteed by basic LED components.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the difference between peak wavelength and dominant wavelength?
A: Peak wavelength (λp) is the wavelength at which the emitted optical power is greatest. Dominant wavelength (λd) is the wavelength of monochromatic light that matches the perceived color of the emitted light. For narrow-spectrum LEDs like this product, the two are very close (571 nm vs. 572 nm).

Q: Can I drive this digital tube continuously at 20mA?
A: Yes, 20mA is below the maximum continuous forward current rating of 25mA. However, you must consider the ambient temperature, as the current rating is derated when exceeding 25°C.

Q: Since it cannot operate in reverse bias, why is the reverse current specification important?
A: IR specification is a quality and leakage current test parameter. High reverse current may indicate a manufacturing defect in the semiconductor junction.

Q: What does "Luminous Intensity Grade" mean?
A: This means the devices are tested and sorted (graded) based on their measured light output at a standard test current. This allows designers to select digits from the same brightness grade to ensure uniform brightness in an array and prevent one digit from appearing dimmer than another.

10. Practical Use Case Examples

Consider designing a simple digital timer with a resolution of 1 second. The seconds digit of this unit can be implemented using the LTS-5825CKG-PST1. A microcontroller will be used to control the display. If multiplexing other digits, the common anode pin will be connected to a positive supply voltage (e.g., 5V) with a suitable current-limiting scheme. The eight cathode pins (segments A-G and DP) will be connected to the GPIO pins of the microcontroller, each through its own current-limiting resistor (e.g., with a 5V supply, considering Vf is approximately 2.1V, around 150Ω corresponds to 20mA current). The software will cycle through displaying digits 0-9, turning on the corresponding combination of cathode pins each second. High brightness and contrast ensure the digits are easily readable from a distance, while low power consumption helps improve overall system efficiency.

11. Brief Introduction to Working Principles

Wannan na'urar tana aiki bisa ka'idar haske ta lantarki na semiconductor p-n junction. Lokacin da aka sanya ƙarfin lantarki mai kyau (anode yana da kyau idan aka kwatanta da cathode) wanda ya wuce ƙarfin ginin junction, electrons daga yankin n-type da ramuka daga yankin p-type ana shigar da su cikin yankin aiki, kuma a can suke haɗuwa. A cikin AlInGaP LED, wannan haɗuwa yana sakin makamashi galibi a cikin nau'in photons (haske) a cikin kewayon tsayin haske na kore. Takamaiman abun ciki na gawa na aluminum, indium, gallium da phosphide yana ƙayyade makamashin tazarar band, wanda hakan ke ƙayyade launin hasken da ake fitarwa. GaAs substrate mara kyau yana ɗaukar duk wani haske da ake fitarwa ƙasa, yana haɓaka ingantaccen ingantaccen fitar da haske a saman na'urar.

12. Technology Trends

Trends in LED display technology continue to move towards higher efficiency, miniaturization, and higher reliability. While AlInGaP is a mature and highly efficient technology for red, orange, amber, and green LEDs, new materials like indium gallium nitride (InGaN) can now cover the entire visible spectrum, including green and blue, with very high efficiency. For single-digit displays, the trends are thinner packages, higher pixel density (for dot-matrix alphanumeric displays), and integration with driver ICs or smart features. However, for specific applications requiring a simple, robust, high-brightness single digit, discrete segment tubes like the LTS-5825CKG-PST1 remain a cost-effective and reliable solution. Environmental considerations are also driving the elimination of hazardous substances and improvements in the recyclability of packaging materials.