LTST-C193TBKT-2A Blue LED Datasheet - Dimensions 1.6x0.8x0.35mm - Voltage 2.55-2.95V - Power 76mW - Technical Documentation

1. Product Overview

This document provides the complete technical specifications for the LTST-C193TBKT-2A, a Surface-Mount Device (SMD) Light-Emitting Diode (LED). This component belongs to the category of ultra-miniaturized optoelectronic devices, specifically designed for modern space-constrained electronic assemblies. Its primary function is to provide a reliable and efficient blue light source for status indication, backlighting, and decorative lighting applications.

The core advantage of this LED lies in its extremely low profile height and high brightness output. With a height of only 0.35 mm, it is classified as an ultra-thin chip LED, enabling its application in ultra-thin consumer electronics, wearable devices, and other scenarios where vertical space is extremely valuable. The device utilizes an InGaN (Indium Gallium Nitride) semiconductor chip, which is the industry-standard technology for producing efficient blue and green LEDs. This chip technology is renowned for its stability and performance.

The target market for this component is broad, encompassing manufacturers of office automation equipment, communication devices, home appliances, and various consumer electronics. Its compatibility with automatic placement equipment and standard infrared (IR) reflow soldering processes makes it suitable for high-volume automated production lines, ensuring consistent quality and reducing assembly costs.

2. In-depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

Absolute Maximum Ratings define the stress limits that may cause permanent damage to the device. These are not operating conditions. For the LTST-C193TBKT-2A, the key limits are as follows:

• Power Dissipation (Pd):76 mW. This is the maximum power that the LED package can dissipate in the form of heat without affecting its performance or lifespan. Exceeding this limit (typically by driving the LED with excessive current) will cause an uncontrolled rise in junction temperature.
• DC Forward Current (I_F):20 mA. This is the maximum continuous forward current recommended for reliable long-term operation. The typical operating current for testing optical parameters is much lower, at 2 mA.
• Peak Forward Current:100 mA, but only applicable under pulse conditions with a duty cycle of 1/10 and a pulse width of 0.1 ms. This rating is very important for applications requiring brief, high-intensity flashes.
• Temperature Range:The device can operate in an ambient temperature range of -20°C to +80°C and can be stored at temperatures from -30°C to +100°C.
• Infrared Soldering Conditions:The package can withstand a peak reflow soldering temperature of up to 260°C for a maximum of 10 seconds, which complies with Pb-free soldering process standards.

2.2 Electrical and Optical Characteristics

These parameters are measured at a standard ambient temperature of 25°C and define the device's performance under normal operating conditions.

• Luminous Intensity (I_V):When the forward current (I_F) is 2 mA, the range is from a minimum of 4.50 millicandelas (mcd) to a maximum of 18.0 mcd. Intensity measurements are performed using a sensor filtered to match the photopic response of the human eye (CIE curve).
• Viewing angle (2θ_1/2):130 degrees. This wide viewing angle is a characteristic of clear lenses (without diffusers), meaning the emitted light is distributed over a broad area, suitable for applications requiring large-area illumination rather than a focused beam.
• Peak Emission Wavelength (λ_P):468 nanometers (nm). This is the specific wavelength at which the spectral power output is highest.
• Dominant Wavelength (λ_d):At I_FAt =2mA, the range is from 465.0 nm to 480.0 nm. This is the single wavelength perceived by the human eye that defines the color of light, derived from the CIE chromaticity diagram.
• Spectral line half-width (Δλ):25 nm. This indicates spectral purity; a smaller value means the light is closer to monochromatic.
• Forward voltage (V_F):At I_FWhen =2mA, the range is 2.55V to 2.95V. This is the voltage drop across the LED when it is conducting current. It is a key parameter for designing the current limiting circuit.
• Reverse current (I_R):When a reverse voltage (V_R) of 5V is applied, it is a maximum of 10 microamperes (μA).Important note:This LED is not designed for reverse bias operation; this test is solely for characterizing leakage current characteristics.

3. Grading System Description

To ensure consistency in mass production, LEDs are binned according to performance. The LTST-C193TBKT-2A employs a three-dimensional binning system.

3.1 Forward Voltage Binning

The unit is volts (V), with a test current of 2 mA. Binning ensures that LEDs in a circuit have similar voltage drops, resulting in uniform brightness when connected in parallel.

• Gear A: 2.55V (min) to 2.65V (max)
• Gear 1: 2.65V to 2.75V
• Gear 2: 2.75V to 2.85V
• Gear 3: 2.85V to 2.95V

The tolerance within each gear is ±0.1V.

3.2 Luminous Intensity Binning

The unit is millicandela (mcd), measured at I_F=2mA. This allows for the selection of LEDs for applications requiring specific brightness levels.

• Grade J: 4.50 mcd to 7.10 mcd
• Gear K: 7.10 mcd to 11.20 mcd
• Gear L: 11.20 mcd to 18.0 mcd

The tolerance within each bin is ±15%.

3.3 Dominant Wavelength Binning

The unit is nanometer (nm), in I_FMeasured at =2mA. This controls the precise hue of blue.

• Gear AC: 465.0 nm to 470.0 nm (bluer, shorter wavelength)
• Gear AD: 470.0 nm to 475.0 nm
• Gear AE: 475.0 nm to 480.0 nm (slightly greenish, longer wavelength)

The tolerance within each gear is ±1 nm.

4. Performance Curve Analysis

Although the datasheet references specific charts (e.g., Figure 1 for spectral distribution, Figure 6 for viewing angle), the typical behavior of such InGaN LEDs can be described as follows:

• Current vs. Voltage (I-V) Curve:Forward voltage (V_F) has a positive temperature coefficient; for a given current, it decreases slightly as the junction temperature increases. The curve exhibits an exponential relationship near the turn-on voltage (approximately 2.5V) and becomes more linear at higher currents.
• Luminous intensity vs. current (L-I curve):Within the normal operating range (e.g., up to 20mA), the light output is roughly proportional to the forward current. However, efficiency (lumens per watt) typically peaks at a certain current below the maximum rating and then decreases due to thermal effects and efficiency droop.
• Temperature Characteristics:The luminous intensity of InGaN blue LEDs typically decreases as the junction temperature increases. The dominant wavelength also shifts slightly with increasing temperature (usually towards longer wavelengths).
• Spectral Distribution:The spectrum is a Gaussian curve centered at a peak wavelength of 468 nm with a full width at half maximum of 25 nm.

5. Mechanical and Packaging Information

5.1 Package Size

LED hii inafuata vipimo vya kifurushi cha kawaida cha EIA. Vipimo muhimu (kwa milimita) ni pamoja na urefu wa 1.6mm, upana wa 0.8mm na urefu wa kipekee wa nyembamba sana wa 0.35mm. Michoro ya kiufundi inabainisha eneo la pedi za kuuzia, muundo wa kijenzi na uvumilivu (kawaida ±0.10mm).

5.2 Polarity Identification

Cathode kwa kawaida huwa na alama, kama vile mfuo, alama ya kijani kwenye mkanda, au kona iliyopigwa kwenye kifaa yenyewe. Lazima kuzingatia upeo sahihi wakati wa kukusanyisha ili kuzuia uharibifu kutokana na voltage ya nyuma.

5.3 Recommended Pad Design

Pad pattern recommendations are provided to ensure reliable solder joint formation and proper alignment during reflow soldering. The recommended stencil thickness for solder paste is a maximum of 0.10mm to prevent bridging between closely spaced pads.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Temperature Profile

Provides a recommended infrared (IR) reflow soldering temperature profile suitable for lead-free processes, compliant with JEDEC standards. Key parameters include:

• Preheat:150°C to 200°C.
• Preheat time:Maximum 120 seconds to fully activate the flux and minimize thermal shock.
• Peak temperature:Maximum 260°C.
• Time above liquidus:The example curve on page 3 shows the critical time the solder is in a molten state, which must be controlled to ensure proper solder joint formation.
• Total soldering time at peak temperature:Mafi tsawon daƙiƙa 10. Ba za a maimaita wannan tsari fiye da sau biyu ba.

Saboda ƙirar allon da'ira, man guduro, da halayen murhun sake dawowa sun bambanta, wannan lanƙwasa manufa ce ta gama gari, dole ne a tabbatar da ita don takamaiman saitunan samarwa.

6.2 Manual Welding

If manual soldering is necessary, use a soldering iron with a temperature not exceeding 300°C, and limit the contact time per operation to a maximum of 3 seconds. Overheating can damage the plastic package and semiconductor chip.

6.3 Cleaning

Do not use unspecified chemical cleaners. If cleaning is required after soldering, immerse the LED in ethanol or isopropyl alcohol at room temperature for no more than one minute. Strong solvents can damage the epoxy lens and package.

6.4 Storage and Handling

• ESD Precautions:LED is sensitive to Electrostatic Discharge (ESD). Use an anti-static wrist strap, anti-static mat, and properly grounded equipment during handling.
• Moisture Sensitivity:When stored in the original sealed moisture barrier bag with desiccant at ≤30°C and ≤90% relative humidity, the device has a shelf life of one year. Once the bag is opened, LEDs should be stored at ≤30°C and ≤60% relative humidity.
• Floor Life:Components exposed to ambient air should undergo infrared reflow soldering within 672 hours (28 days). For longer exposure, they should be stored in a sealed container with desiccant or in a nitrogen dry box. If exposure exceeds 672 hours, baking at approximately 60°C for at least 20 hours prior to soldering is recommended to remove absorbed moisture and prevent "popcorn" effect during reflow.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

LEDs are supplied in industry-standard embossed carrier tape and sealed with cover tape.

• Reel dimensions:Diameter 7 inches.
• Quantity per roll:5000 pieces.
• Minimum package quantity:Remaining quantity starts from 500 pieces.
• Missing Parts:A maximum of two consecutive empty positions are allowed in the reel.
• Standard:Packaging conforms to ANSI/EIA-481-1-A-1994 specification.

8. Application Suggestions

8.1 Typical Application Scenarios

• Status Indication:Power-on, battery charging, network activity, and mode indicator lights in smartphones, tablets, laptops, and IoT devices.
• Backlighting:Used in consumer electronics and appliances for membrane switches, small LCD displays, or decorative panels.
• Decorative Lighting:Ambient lighting in automotive interiors, gaming peripherals, and home electronics.

8.2 Design Considerations

• Current Limiting:Always use a series resistor or constant current driver to limit the forward current to the desired level (e.g., 2mA for typical brightness, 20mA for maximum brightness). Do not connect directly to a voltage source.
• Thermal Management:Although power consumption is low, if operating at high ambient temperatures or near the maximum current, ensure sufficient PCB copper area or thermal vias under the pad to aid heat dissipation and maintain LED lifespan and color stability.
• Optical Design:Transparent lenses produce a Lambertian emission pattern (wide viewing angle). If a more focused beam is required, external secondary optics (lenses or light guides) are necessary.
• Application Scope:This component is suitable for standard commercial and industrial applications. For applications requiring extremely high reliability where failure could compromise safety (e.g., aviation, medical life support), the component manufacturer must be consulted for suitability assessment.

9. Technical Comparison and Differentiation

The primary differentiating factor of the LTST-C193TBKT-2A is its0.35mm heightCompared to standard 0603 or 0402 LEDs, which typically have a height of 0.6-0.8mm, its profile height is reduced by 40-50%. This is a key advantage in the ongoing trend of device miniaturization, especially for smartphones, ultra-thin laptops, and wearable technology with severely limited internal space.

Furthermore, the combination of its ultra-thin profile and relatively high luminous intensity (up to 18.0 mcd at only 2mA) is noteworthy. Many LEDs of similar thickness may sacrifice brightness. The use of mature InGaN chips ensures good color consistency and reliability within its specified bins.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 What value of resistor should be selected when using a 5V power supply?

Using Ohm's Law (R = (V_{Power supply}- V_F) / I_F), and assuming a typical V_Fis 2.8V, the required I_Fis 10mA: R = (5V - 2.8V) / 0.010A = 220 ohms. For a conservative design, ensuring the current does not exceed the limit, the maximum V from the datasheet should be used._F(2.95V) Calculation: R_{Minimum value}= (5V - 2.95V) / 0.010A = 205 ohms (use standard value of 220Ω or 240Ω).

10.2 Can I operate this LED continuously at its maximum current of 20mA?

A'a, amma akwai muhimman abubuwa da za a lura. A 20mA, amfani da wutar lantarki ya kusan 2.8V * 0.020A = 56mW, wanda ya ƙasa iyakar 76mW. Duk da haka, aiki a matsakaicin ƙimar yana haifar da ƙarin zafi, wanda zai iya rage rayuwar LED, kuma a tsawon lokaci yana haifar da ɗan canjin launi da raguwar ingancin haske. Don mafi kyawun rayuwa da kwanciyar hankali, idan haske ya isa, ana ba da shawarar aiki a ƙananan ƙarfin kwarara (misali 5-10mA).

10.3 Me ya sa kusurwar gani ta yi fadi (130°) haka?

Transparent (non-diffuse) epoxy resin lenses are molded into a hemispherical shape that covers the tiny LED chip. This shape acts as a lens, refracting light from the small point source and distributing it across a very wide angle. This is ideal for applications where the LED needs to be visible from multiple different viewing positions, not just head-on.

10.4 Menene bambanci tsakanin tsayin kalaman kololuwa da babban tsayin kalaman?

Peak Wavelength (λ_P):The physical wavelength at which an LED emits the maximum optical power. It is a property of the semiconductor material.Dominant Wavelength (λ_d):The perceived wavelength. It is the wavelength of monochromatic light that appears to a standard human observer to have the same color as the LED light. These two values differ due to the shape of the human eye sensitivity curve and the spectral width of the LED. The dominant wavelength is more relevant for color specification in design.

11. Practical Design and Application Cases

Scenario: Designing a multi-LED status indicator strip for a portable Bluetooth speaker.The design requires 5 blue LEDs to indicate battery level. Space behind the thin plastic diffuser panel is extremely limited.

Component Selection:The LTST-C193TBKT-2A was chosen for its 0.35mm height, allowing it to be mounted within the slim housing. Its 130° wide viewing angle ensures the indicator strip is visible from various angles.

Circuit Design:The LED will be driven by the 3.3V regulator on the motherboard. The target brightness is the middle value of the K grade (approximately 9 mcd), and a forward current of 5mA is selected for good visibility and power efficiency. For conservative design, the maximum V_F2.95V is used for calculation: R = (3.3V - 2.95V) / 0.005A = 70 ohms. A standard 68Ω resistor is selected, resulting in a slightly higher current of approximately 5.1mA.

PCB Layout:Use the pad layout recommended in the datasheet. Connect a small amount of copper to the cathode pad (typically thermally connected to the LED substrate) to aid heat dissipation, especially since the five LEDs will be closely spaced together.

Assembly:Place LEDs from 8mm tape using automated equipment. The assembly line uses a proven, lead-free reflow temperature profile compliant with JEDEC recommendations in the datasheet, with careful monitoring of peak temperature and time above liquidus to prevent thermal damage to the ultra-thin package.

12. Introduction to Technical Principles

LTST-C193TBKT-2A is based on an InGaN (Indium Gallium Nitride) semiconductor chip. The light emission principle is electroluminescence. When a forward voltage is applied across the semiconductor p-n junction, electrons from the n-type region and holes from the p-type region are injected into the active region. There, they recombine, releasing energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor material. By adjusting the ratio of indium to gallium in the InGaN compound, the bandgap can be tuned to produce light in the blue, green, and near-ultraviolet spectral ranges. The chip is then encapsulated in transparent epoxy resin, forming a lens that protects the delicate semiconductor structure from mechanical and environmental damage and helps extract light efficiently from the chip.

13. Industry Trends and Development

The development of LEDs like LTST-C193TBKT-2A is driven by several key trends in the electronics industry:

• Miniaturization:The relentless pursuit of thinner and smaller consumer devices demands components with continuously shrinking footprint and height. A 0.35mm profile height represents the current benchmark for chip LEDs in high-volume applications.
• Efficiency Improvement:Continuous improvements in InGaN epitaxial growth and chip design steadily increase the luminous efficacy (lumens per watt) of blue LEDs, allowing for brighter output at lower currents, thereby reducing power consumption and heat generation.
• Advanced Packaging:Packaging technology is crucial for ultra-thin devices. The development of mold compounds, die attach materials, and Wafer Level Packaging (WLP) technology has made micro-components more robust and reliable.
• Automation and Standardization:Compatibility with tape-and-reel packaging, automated placement, and standard reflow profiles is essential for integration into the global automated manufacturing ecosystem, thereby maintaining low assembly costs and high quality.

Future development directions may include thinner packaging, integration of drive circuits within LED packages (smart LEDs), and further improvements in color consistency and thermal performance.