SMD LED LTST-C193KSKT-5A Datasheet - Size 1.6x0.8x0.35mm - Voltage 1.7-2.3V - Power 50mW - Yellow - Technical Documentation

1. Product Overview

This document details the specifications of the LTST-C193KSKT-5A surface-mount device (SMD) LED. This component belongs to the miniature LED series, specifically designed for automated printed circuit board (PCB) assembly processes and applications with stringent space constraints. Its compact form factor and reliable performance enable integration into a wide range of modern electronic devices.

1.1 Siffofi da fa'idodi na asali

The LTST-C193KSKT-5A possesses several key technical advantages that enhance its usability and performance in demanding applications.

• RoHS Compliant:This device is manufactured in compliance with the Restriction of Hazardous Substances Directive, ensuring it is free from specific hazardous substances such as lead, mercury, and cadmium.
• Ultra-thin form factor:With a height of only 0.35 mm, it belongs to the ultra-thin chip LED category, suitable for extremely slim consumer electronics and displays.
• High-brightness AlInGaP chip:Utilizes aluminum indium gallium phosphide (AlInGaP) semiconductor material, renowned for producing high-efficiency light in the yellow, orange, and red spectral regions with good stability.
• Industry-standard packaging:Packaged in 8mm carrier tape, wound on 7-inch diameter reels, compatible with standard automated pick-and-place equipment used in high-volume electronics manufacturing.
• Process compatibility:Designed to be compatible with infrared (IR) reflow soldering processes, the standard process for assembling surface-mount components. Its driving characteristics are also compatible with integrated circuits (I.C.).

1.2 Kasuwa da aikace-aikace

The combination of small size, high brightness, and high reliability opens up numerous application possibilities across multiple industry sectors.

• Telecommunications Equipment:Used for status indicator lights in cordless phones, mobile phones, and network equipment.
• Computers and Office Automation:Used for laptop keyboard backlighting and status indicator lights on various peripherals.
• Consumer Electronics and Home Appliances:For power, mode, or function indicators in audio-visual equipment, kitchen appliances, and other household devices.
• Industrial equipment:For panel indicators in machinery and control systems.
• Display technology:Suitable for micro-displays and as a light source for symbols and signal indicators.

2. Sigogi na fasaha: Cikakken bayani mai zurfi

This section provides a detailed breakdown of the electrical, optical, and environmental limits and characteristics of LEDs.

2.1 Matsakaicin ƙididdiga na gaba ɗaya

These ratings define the stress limits that may cause permanent damage to the device. Operation at or beyond these limits is not recommended. All ratings are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation (Pd):50 mW. This is the maximum power the LED package can dissipate as heat.
• Continuous Forward Current (IF):20 mA DC. The maximum steady-state current that can be applied.
• Peak Forward Current:40 mA, permitted only under pulse conditions (1/10 duty cycle, 0.1ms pulse width) to briefly achieve higher light output.
• Reverse Voltage (VR):5 V. Exceeding this voltage under reverse bias may cause junction breakdown.
• Operating Temperature Range:-30°C to +85°C. The ambient temperature range over which the device is designed to operate.
• Storage Temperature Range:-40°C to +85°C.
• Infrared Soldering Conditions:Can withstand a peak temperature of up to 260°C for a maximum of 10 seconds during reflow soldering.

2.2 Electro-Optical Characteristics

These are typical performance parameters measured under specific test conditions (unless noted, Ta=25°C, IF=5 mA).

• Luminous Intensity (Iv):Ranges from 7.1 to 45.0 millicandelas (mcd). This wide range is managed through a binning system (see Section 3). Intensity is measured using a sensor filtered to match the human eye's photopic response (CIE curve).
• Viewing Angle (2θ1/2):130 degrees. This is the full angle at which the luminous intensity drops to half of its axial measured value, indicating a very wide emission pattern.
• Peak Emission Wavelength (λP):591.0 nm. Wavelength at the peak of the LED spectral output curve.
• Dominant Wavelength (λd):587.0 - 594.5 nm. This is the single wavelength perceived by the human eye that defines the color (yellow). It is derived from the CIE chromaticity coordinates.
• Spectral Line Half Width (Δλ):15 nm. A measure of spectral purity; a smaller value indicates better monochromaticity of the light source.
• Forward Voltage (VF):1.7 - 2.3 V at 5 mA current. The voltage drop across the LED when operating.
• Reverse Current (IR):When a 5V reverse bias is applied, the maximum current is 10 μA.

2.3 Thermal Considerations

Although not explicitly detailed in the form of thermal resistance (θJA), the maximum power dissipation of 50 mW and the operating temperature range define the thermal operating window. Proper PCB layout, including providing sufficient copper foil area for the solder pads, is crucial for heat dissipation, especially when operating near the maximum rated current. Exceeding the maximum junction temperature will accelerate light output degradation and shorten the operational lifespan.

3. Binning System Description

To ensure consistency in mass production, LEDs are binned according to their performance. The LTST-C193KSKT-5A employs a three-dimensional binning system based on forward voltage, luminous intensity, and dominant wavelength (hue).

3.1 Forward Voltage (VF) Binning

Binning ensures that LEDs in a circuit have similar voltage drops, promoting brightness uniformity when connected in parallel. The tolerance per bin is ±0.1V.
Gear E2: 1.7V - 1.9V
Gear E3: 1.9V - 2.1V
Gear E4: 2.1V - 2.3V

3.2 Luminous Intensity (Iv) Binning

This binning groups LEDs based on their light output at the standard test current (5mA). The tolerance for each bin is ±15%.
Gear K: 7.1 - 11.2 mcd
Gear L: 11.2 - 18.0 mcd
Gear M: 18.0 - 28.0 mcd
Gear N: 28.0 - 45.0 mcd

3.3 Hue / Dominant Wavelength (λd) Binning

Yana muhimman aikace-aikace masu tsaurin buƙatu na launi, wannan rarrabuwa yana tabbatar da daidaitaccen yanayin rawaya. Kowane mataki yana da ƙimar kuskure na ±1 nm.
Mataki J: 587.0 - 589.5 nm
Mataki K: 589.5 - 592.0 nm
Mataki L: 592.0 - 594.5 nm

4. Performance Curve Analysis

Ko da yake takardar ƙayyadaddun bayanai ta yi nuni da takamaiman lanƙwan zane, an bayyana ma'anarsa a nan.

4.1 Current-Voltage (I-V) Characteristics

Ƙarfin lantarki na gaba (VF) yana da ingantaccen ƙimar zafin jiki, kuma yana ƙaruwa yayin da ƙarfin lantarki ke ƙaruwa. Yayin ƙirƙirar da'irar iyakancewar ƙarfin lantarki, dole ne a yi la'akari da yanayin kewayon VF na 1.7-2.3V a ƙarashin 5mA. Tura LED da matsakaicin ƙarfin lantarki na DC na 20mA zai haifar da mafi girman ƙarfin lantarki na gaba, yana buƙatar daidaitawar ƙirar wutar lantarki ko direba daidai.

4.2 Temperature Dependence

Like all semiconductors, LED performance is sensitive to temperature. The luminous intensity of AlInGaP LEDs typically decreases as the junction temperature increases. Therefore, maintaining a low thermal resistance path from the LED junction to the environment is key to achieving stable, long-term brightness. The specified operating temperature range of -30°C to +85°C defines the environmental limits of this relationship.

4.3 Spectral Distribution

The LED emits light in a narrow band with a center wavelength of approximately 591 nm (peak) and a half-width of 15 nm, which defines its yellow color. The dominant wavelength (λd) is the parameter used for hue binning. The spectrum is largely independent of current, but the peak wavelength may shift slightly with temperature.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This LED employs a compact chip-scale package. Key dimensions (in millimeters) are approximately: length 1.6mm, width 0.8mm, and an extremely low height of 0.35mm. Refer to the detailed mechanical drawing for precise tolerances (typically ±0.1mm) and features such as the cathode identification mark.

5.2 Recommended PCB Land Pattern

A recommended PCB land pattern (footprint) is provided to ensure reliable soldering and mechanical stability. This pattern typically includes pads slightly larger than the device terminals to facilitate good solder fillet formation. Adhering to this recommendation helps prevent "tombstoning" (component lifting on one end) during reflow soldering.

5.3 Polarity Identification

The device has an anode and a cathode. The datasheet specifies the method for identifying the cathode, which is crucial for correct orientation during assembly and circuit operation. Incorrect polarity will prevent the LED from illuminating, and applying a reverse voltage exceeding 5V may damage it.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Parameters

This device is rated for infrared (IR) reflow soldering with a peak temperature of 260°C for a maximum of 10 seconds. A recommended reflow profile is provided, typically following JEDEC standards. It includes:
- Preheat:150-200°C, maximum 120 seconds, to gradually heat the board and activate the flux.
- Reflow (Liquidus):Peak temperature not exceeding 260°C, with time above 260°C kept to a minimum.
- Cooling:A controlled cooling phase.
This curve must be characterized for a specific PCB assembly (considering board thickness, component density, and solder paste type).

6.2 Manual Soldering

For manual rework, use a soldering iron with a temperature not exceeding 300°C. The contact time with the LED terminals in a single operation should be limited to a maximum of 3 seconds to prevent thermal damage to the plastic package and semiconductor chip.

6.3 Storage and Handling Conditions

- Moisture Sensitivity Level (MSL):This device is rated MSL 2a. Once the original moisture barrier bag is opened, the components must undergo IR reflow soldering within 672 hours (28 days) under factory floor conditions (≤30°C/60% RH).
- Long-Term Storage:For storage exceeding 672 hours from the original sealed bag, components should be stored in a dry cabinet with desiccant or a sealed container.
- Baking:Components exceeding the floor life should be baked at approximately 60°C for at least 20 hours prior to soldering to remove absorbed moisture and prevent the "popcorn" effect during reflow.
- ESD Precautions:LEDs are sensitive to electrostatic discharge (ESD). Handle using appropriate ESD control measures, such as grounded wrist straps, antistatic mats, and conductive containers.

6.4 Cleaning

If post-solder cleaning is required, use only specified solvents. Immersing the LED in ethanol or isopropyl alcohol at room temperature for less than one minute is acceptable. Avoid using unspecified or aggressive chemical cleaners to prevent damage to the epoxy lens or package.

7. Packaging and Ordering Information

7.1 Standard Packaging

The product is packaged in industry-standard embossed carrier tape for automated handling. The carrier tape width is 8mm. This tape is wound on a 7-inch (178mm) diameter reel.

7.2 Reel Specifications and Quantity

Each full 7-inch reel contains 5000 pieces of LTST-C193KSKT-5A LEDs. The carrier tape is equipped with a cover tape to protect the components during transportation and handling. The packaging complies with the ANSI/EIA-481 specification.

7.3 Minimum Order Quantity and Part Number

The standard part number is LTST-C193KSKT-5A. The suffix "-5A" may indicate a specific bin combination or other product variant. For non-full reel orders, a minimum packaging quantity of 500 pieces is typically available as remainder stock.

8. Application Suggestions and Design Considerations

8.1 Current Limiting

LEDs are current-driven devices. Always use a series current-limiting resistor or a constant current driver circuit to set the operating current. The resistor value can be calculated using Ohm's Law: R = (Supply Voltage - LED Forward Voltage) / Desired Current. Select a resistor with a power rating suitable for the power dissipation. For example, to drive an LED from a 3.3V supply at 5mA with a typical VF of 2.0V: R = (3.3V - 2.0V) / 0.005A = 260Ω. Using a standard 270Ω resistor is appropriate.

8.2 Thermal Management in Design

For applications operating at high current (e.g., close to 20mA) or in high ambient temperatures, thermal management is crucial. Use the recommended PCB pad layout and connect the thermal pad to a sufficient area of copper pour to act as a heat sink. This helps conduct heat away from the LED junction, maintaining brightness and lifespan.

8.3 Optical Design

The 130-degree viewing angle provides a very wide emission pattern, making it ideal for status indicators that need to be viewed from different angles. For applications requiring a more directional beam, secondary optics (such as a lens mounted above the LED) are needed. The crystal clear lens of this LED is suitable for light guides or diffusers in backlighting applications.

9. Technical Comparison and Differentiation

The primary differentiating factors of the LTST-C193KSKT-5A are itsultra-thin 0.35 mm heightand its use ofAlInGaP technologyfor yellow light emission.

• Compared to standard SMD LEDs (e.g., 0603, 0402):This chip LED is significantly thinner, enabling its use in space-constrained products where even standard 0.6mm tall LEDs are too large.
• Compared to other yellow LED technologies:Compared to older yellow Gallium Phosphide (GaP) LEDs, AlInGaP offers significantly higher luminous efficacy and better temperature stability, resulting in brighter and more consistent light output.
• Compared to white LEDs:For applications requiring pure yellow indication (e.g., specific warning symbols), monochromatic yellow AlInGaP LEDs are more efficient and offer higher color saturation than phosphor-converted white LEDs with yellow filters.

10. Tambayoyin da ake yawan yi (bisa sigogin fasaha)

Q: Can I drive this LED directly from a 3.3V or 5V microcontroller pin?
Amsa: A'a. Dole ne koyaushe ka yi amfani da resistor mai iyakancewar kwarara a jere. Haɗawa kai tsaye zai yi ƙoƙarin ɗaukar wutar lantarki mai yawa, wanda zai iya lalata LED da fitar da microcontroller.

Tambaya: Me ya sa kewayon ƙarfin haske ya yi fadi haka (7.1 zuwa 45.0 mcd)?
Amsa: Wannan shine jimlar kewayon samarwa. Ta hanyar tsarin rarrabawa (K, L, M, N grades), zaka iya zaɓar LED tare da ƙaramin kewayon ƙarfin haske don aikace-aikacenka, don tabbatar da daidaiton haske.

Tambaya: Menene bambanci tsakanin kololuwar tsawon raƙuman ruwa da babban tsawon raƙuman ruwa?
Amsa: Kololuwar tsawon raƙuman ruwa (λP) shine kololuwar zahiri na bakan fitarwa. Babban tsawon raƙuman ruwa (λd) ƙima ce ta lissafi dangane da fahimtar launi; ita ce guda ɗaya tsawon raƙuman ruwa wanda ya dace da launin da idon mutum ya gani. λd ya fi dacewa don ƙayyadaddun launi da rarrabawa.

Tambaya: Sau nawa zan iya sake yin gyarawar wannan LED?
Amsa: Takaddun bayanan sun ƙayyade cewa za a iya aiwatar da tsarin gyarawa sau biyu, kowane lokaci bai wuce 260°C kololuwar zafin jiki ba, na tsawon dakika 10. Maimaita sake gyarawa yana ƙara matsin lamba na zafi.

11. Misalan aikace-aikace na zahiri

Case 1: Ultra-Thin Tablet Keyboard Backlight:Designers are creating a detachable keyboard for a tablet. The space budget for components under the keycaps is extremely limited. The 0.35mm profile of the LTST-C193KSKT-5A allows it to be installed where standard LEDs cannot fit. Multiple LEDs are placed on a flexible PCB under the transparent keycaps. They are driven at 5-10mA by a constant current driver IC, providing uniform, low-power backlighting. The wide viewing angle ensures good light diffusion under each key.

Case 2: Industrial Sensor Status Indicator:A compact industrial proximity sensor requires a bright, reliable status LED to indicate power and detection status. The AlInGaP yellow LED provides high brightness with good visibility in well-lit environments. The designer uses the high-intensity "N" grade LED, driving it at 15mA from the sensor's 24V power supply (using a transistor as a switch) via a current-limiting resistor. The robust SMD package can withstand the vibration and temperature fluctuations typical in industrial environments.

12. Gabatarwar fasaha da aikin tsari

A Light Emitting Diode (LED) is a semiconductor device that emits light through a process called electroluminescence. The core of the LTST-C193KSKT-5A is a chip made of Aluminum Indium Gallium Phosphide (AlInGaP). This III-V compound semiconductor material has a direct bandgap suitable for efficient light emission.

Working Principle:When a forward voltage exceeding the diode junction potential (VF) is applied, electrons from the n-type semiconductor and holes from the p-type semiconductor are injected into the active region. When these charge carriers (electrons and holes) recombine, they release energy. In AlInGaP LEDs, this energy is released primarily as photons (light) in the yellow/orange/red portion of the spectrum. The specific wavelength (color) is determined by the bandgap energy of the semiconductor material, which is engineered by adjusting the ratios of aluminum, indium, gallium, and phosphorus during crystal growth. The generated light escapes through an epoxy lens, which also provides environmental protection.

13. Yanayin masana'antu da Ci gaba

The market for SMD LEDs like the LTST-C193KSKT-5A continues to evolve, driven by several key trends:

• Miniaturization:Driven by consumer electronics (smartphones, wearables, ultra-thin laptops), the demand for thinner and smaller LEDs is relentless. Chip-scale packaging (CSP) and even thinner variants are areas of ongoing development.
• Efficiency Improvements:Advancements in epitaxial growth, chip design, and light extraction techniques continue to push the luminous efficacy (lumens per watt) higher for colored LEDs like AlInGaP, enabling brighter light or lower power consumption.
• Gajerar aminci mai girma:Yayin da LED ke amfani da shi don ƙarin aikace-aikace masu mahimmanci (kayan cikin mota, na'urorin kiwon lafiya), an fi mayar da hankali kan haɓaka dogon lokacin aminci, kwanciyar hankali na launi tare da zafin jiki da lokaci, da aiki a cikin yanayi mara kyau.
• Haɗawa:Yarjejeniyar ita ce haɗa ƙwayoyin LED da yawa (misali RGB don haɗa launuka) cikin fakitin guda ɗaya, ko haɗa LED tare da IC mai tuƙi da dabaru sarrafawa, don samar da tsarin "LED mai hankali".
• Fakiti na ci gaba:Ana haɓaka sabbin kayan fakiti da hanyoyi, don sarrafa zafi daga ƙananan LED masu ƙarfi sosai da kyau, da kuma samar da sarrafa haske madaidaiciya kai tsaye daga fakiti.