SMD LED LTST-C191KGKT-5A Datasheet - 0.55mm Ultra-Thin Height - 2.1V Max Forward Voltage - Green - Technical Documentation

1. Product Overview

This document details the specifications of the LTST-C191KGKT-5A, a Surface-Mount Device (SMD) Light-Emitting Diode (LED). This component belongs to the chip LED series designed for modern compact electronic assemblies. Its primary application is as an indicator light, status signal, or backlight element in consumer electronics, communication equipment, and general electronic devices.

The core advantage of this product lies in its extremely low profile height. A height of only 0.55 mm allows end products to be designed thinner. It utilizes Aluminum Indium Gallium Phosphide semiconductor material as the light-emitting chip, a material renowned for producing high-brightness, high-efficiency light in the red, orange, yellow, and green spectral ranges. The device is packaged on an industry-standard 8 mm carrier tape and wound onto 7-inch reels, making it fully compatible with high-speed automated pick-and-place assembly equipment used in modern electronics manufacturing.

1.1 Main Features

• Ultra-Thin Profile:With a package height of only 0.55 mm, it contributes to slim product designs.
• High Brightness:Utilizes AlInGaP chip technology to achieve excellent luminous intensity.
• Automation-Friendly:Supplied in 8 mm carrier tape, 7-inch reels, compatible with automated assembly lines.
• Robust Assembly:Compatible with infrared reflow and vapor phase reflow soldering processes, including lead-free soldering profiles.
• Standardized Package:Complies with EIA standard dimensions to ensure reliable mounting and soldering.
• Drive Compatibility:IC compatible, meaning it can be driven directly by the output of a standard integrated circuit with appropriate current limiting.

2. Detailed Technical Specifications

2.1 Absolute Maximum Ratings

These ratings define the stress limits that may cause permanent damage to the device. Operation at or near these limits is not guaranteed and should be avoided to ensure reliable operation. All values are specified at an ambient temperature of 25°C.

• Yin amfani da wutar lantarki:75 milliwatts. Wannan shine matsakaicin ƙarfin da na'urar za ta iya ɓata a matsayin zafi.
• Matsakaicin halin yanzu na gaba:_F(PEAK)):80 milliamps. Wannan shine matsakaicin halin yanzu na gaba da aka yarda na ɗan lokaci, yawanci a cikin yanayin bugun jini (1/10 aikin aiki, faɗin bugun 0.1 millisecond).
• Ci gaba da halin yanzu na gaba:_F):30 milliamps DC. Matsakaicin halin yanzu da zai iya ci gaba da gudana ta LED.
• Rage ƙimar halin yanzu:When the ambient temperature exceeds 25°C, the maximum allowable continuous forward current must be linearly reduced at a rate of 0.4 milliamperes per degree Celsius.
• Reverse Voltage:_R):5 volts. The maximum reverse voltage that can be applied across the LED.
• Operating Temperature Range:-55°C to +85°C. The ambient temperature range over which the device is designed to operate.
• Storage Temperature Range:-55°C to +85°C.
• Infrared Soldering Conditions:During the reflow soldering process, it can withstand a peak temperature of up to 260°C for a duration not exceeding 5 seconds.

2.2 Electrical and Optical Characteristics

These are typical performance parameters measured under standard test conditions. They define the expected behavior of the device during normal operation._F=5mA unless noted). They define the expected behavior of the device in normal operation.

• Luminous Intensity:_V):Ranging from 4.5 to 18.0 millicandelas. This is a measure of the LED's brightness as perceived by the human eye, measured using a filter matching the CIE photopic response curve.
• Viewing Angle:_/2):130 degrees. This is the full angle at which the luminous intensity drops to half of its axial measured value. Such a wide viewing angle allows the LED to be seen from a broad range of positions.
• Peak Emission Wavelength:_P):574 nm. Wavelength specific lokacin da ƙarfin hasken fitarwa ya kai matsakaicin ƙima.
• Babban tsawon zango:_d):A ƙarfin na 5 mA, kewayon daga 564.5 nm zuwa 573.5 nm. Wannan shi ne tsawon zango guda ɗaya wanda ya fi wakiltar launin haske a fahimta, wanda ya samo asali daga taswirar launi na CIE. Yana ayyana ma'anar "kore" a wurin launi.
• Ramin rabin faɗin bakan haske:15 nm. Faɗin bakan fitarwa a rabin matsakaicin ƙimar ƙarfinsa. Ƙunƙarar ramin rabin faɗin tana nuna mafi tsabtar launin bakan.
• Ƙarfin lantarki na gaba:_F):A ƙarfin na 5 mA, kewayon daga 1.70 V zuwa 2.10 V. Faɗin ƙarfin lantarki a ƙarshen LED lokacin da aka kunna ƙarfin lantarki.
• Ƙarfin lantarki na baya:_R):Lokacin da aka yi amfani da ƙarfin lantarki na baya na 5 V, matsakaicin 100 µA.
• Ƙarfin ƙwaƙwalwa:A ana auna a 0 volts na gaba da karkatarwa da mitar 1 MHz, ƙimar al'ada shine 40 pF.

3. Bin System Description

Don tabbatar da daidaito a cikin samar da yawa, ana rarraba LED zuwa matakan aiki daban-daban bisa ga ma'auni masu mahimmanci. Wannan yana ba masu zane damar zaɓar na'urorin da suka dace da takamaiman buƙatun daidaiton launi da haske a aikace-aikacensu.

3.1 Forward Voltage Binning

Ana rarraba na'urar bisa ga ƙarfin lantarki na gaba da aka auna a 5mA. Lambar rarrabawa da kewayon da ya dace suna kamar haka:_F) measured at 5mA. The bin code and corresponding range are:

• Lambar Rarrabawa 2:1.70 volts zuwa 1.80 volts
• Gear code 3:1.80 volts to 1.90 volts
• Gear code 4:1.90 volts to 2.00 volts
• Gear code 5:2.00 volts to 2.10 volts

The tolerance within each gear is ±0.1 volts.

3.2 Luminous Intensity Binning

Na'urar ana rarraba ta bisa ga ƙarfin haske da aka auna a ƙarfin 5 milliamps. Lambobin bincike da kewayon da suka dace kamar haka:_V) measured at 5mA. The bin code and corresponding range are:

• Lambar bincike J:4.50 millicandela zuwa 7.10 millicandela
• Lambar bincike K:7.10 millicandela zuwa 11.2 millicandela
• Lambar bincike L:11.2 millicandela zuwa 18.0 millicandela

Rangwame a cikin kowane bincike shine ±15%.

3.3 Dominant Wavelength Binning

Devices are classified based on their dominant wavelength measured at 5mA, which directly correlates to the shade of green. The bin code and corresponding range are as follows:_d) measured at 5mA, which directly correlates to the shade of green. The bin code and corresponding range are:

• Bin Code B:564.5 nm to 567.5 nm
• Bin Code C:567.5 nm to 570.5 nm
• Bin Code D:570.5 nm to 573.5 nm

The tolerance within each gear is ±1 nm.

4. Performance Curve Analysis

Although specific graphical curves are referenced in the datasheet, the provided data allows for the analysis of key relationships.

4.1 Relationship Between Forward Current and Forward Voltage

Forward voltage is specified at a test current of 5mA, with a typical range of 1.70V to 2.10V. Like all diodes, the LED's forward voltage has a positive temperature coefficient and increases slightly with increasing drive current. The specified forward voltage range must be considered when designing the voltage margin of the drive circuit._F) is specified at a test current of 5mA, with a typical range of 1.70V to 2.10V. Like all diodes, the LED's V_Fhas a positive temperature coefficient and will also increase slightly with higher drive currents. The specified V_Frange must be considered when designing the driving circuit's voltage headroom.

4.2 Relationship Between Luminous Intensity and Forward Current

Over a considerable range, the luminous intensity is approximately proportional to the forward current. The rated intensity value is given at a standard test current of 5 mA. Operating at the maximum continuous current of 30 mA yields significantly higher light output, but thermal management and lifetime considerations become critical.

4.3 Spectral Characteristics

The peak emission wavelength is typically 574 nm, with a spectral half-width of 15 nm. The dominant wavelength, which defines the perceived color, ranges from 564.5 nm to 573.5 nm depending on the bin. This firmly places its emitted light in the green region of the visible spectrum. The relationship between peak wavelength and dominant wavelength is influenced by the precise shape of the emission spectrum.

4.4 Zafi Janyewar Zafi

The datasheet clearly specifies a derating factor of 0.4 mA/°C for the maximum continuous forward current when the ambient temperature exceeds 25°C. This is a critical design parameter. For example, at an ambient temperature of 85°C, the maximum allowable continuous current is reduced by (85-25)*0.4 = 24 mA. Therefore, the maximum current at 85°C is 30 mA - 24 mA = 6 mA. Exceeding this derated current increases the risk of accelerated degradation or failure.

5. Bayanin Injiniya da Kunshewa

5.1 Girman Kunshewa

This device utilizes an EIA standard chip LED package. A key mechanical characteristic is its 0.55 mm height. The detailed dimension drawing will show the length, width, and the positions of the cathode/anode terminals. Unless otherwise specified on the drawing, the standard tolerance for all dimensions is ±0.10 mm.

5.2 Gane Polarity

For surface-mount LEDs, polarity is typically indicated by a marking on the package, such as a dot, notch, or colored stripe near the cathode. The orientation in the carrier tape and reel packaging ensures feeding into automated equipment with the correct polarity. The cathode is usually connected to a larger internal lead frame or thermal pad for better thermal performance.

5.3 Recommended Solder Pad Layout

Provides the recommended pad pattern for printed circuit boards. This pattern is designed to ensure reliable solder joint formation during reflow soldering, provide sufficient mechanical strength, and prevent solder bridging. It typically includes a pad area slightly larger than the device terminal to facilitate the formation of a good solder fillet.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

The datasheet provides two recommended infrared reflow soldering profiles: one for conventional tin-lead solder processes and one for lead-free solder processes. The lead-free profile must be used when employing tin-silver-copper solder paste. Key parameters for the lead-free process include:

• Preheating:Gradually increase temperature to avoid thermal shock.
• Soak/Preheat Time:Typically up to 120 seconds maximum.
• Peak Temperature:Maximum 260°C.
• Time Above Liquidus:The time the component spends above the solder's melting point should be controlled, typically a maximum of about 5 seconds at peak temperature.

Adhering to these profiles is crucial to prevent damage to the LED's plastic lens and internal bonding wires from overheating or thermal stress.

6.2 Wave Soldering and Hand Soldering

If wave soldering is used, it is recommended to include preheating below 100°C for up to 60 seconds and exposure to a solder wave at a maximum of 260°C for no more than 10 seconds. For manual rework using a soldering iron, the tip temperature should not exceed 300°C, the contact time per solder joint should be limited to within 3 seconds, and only one repair cycle should be performed.

6.3 Cleaning

If cleaning is required after soldering, only specified solvents should be used. The datasheet recommends immersion in ethanol or isopropyl alcohol at room temperature for no more than one minute. Unspecified chemical cleaners may damage the plastic lens or encapsulant material, leading to cracking or fogging.

6.4 Storage Conditions

LEDs are moisture-sensitive devices. For situations where they are stored outside the original moisture barrier packaging, environmental control is crucial. The recommended storage conditions are a temperature not exceeding 30°C and a relative humidity not exceeding 70%. If stored outside the original bag for more than 672 hours, the components must be baked at approximately 60°C for at least 24 hours before reflow soldering to remove absorbed moisture and prevent "popcorn" damage during the high-temperature reflow process.

7. Packaging and Ordering Information

7.1 Carrier Tape and Reel Specifications

The product is supplied in embossed carrier tape with protective cover tape, wound on 7-inch diameter reels. The standard packaging quantity is 5000 pieces per reel. For quantities that are not multiples of 5000, the minimum packaging quantity for the remainder is 500 pieces. The packaging conforms to the ANSI/EIA 481-1-A-1994 standard, ensuring compatibility with automated equipment. The carrier tape ensures correct component orientation and protects the device during handling and transportation.

7.2 Part Number Structure

The part number LTST-C191KGKT-5A encodes specific attributes of the device. While the complete company naming logic can be complex, it typically includes a series identifier, color/performance code, and possibly a bin or packaging code. The "Water Clear" lens description indicates the lens material is transparent, allowing the native color of the AlInGaP chip to be seen directly, thereby maximizing light output.

8. Application Recommendations

8.1 Typical Application Scenarios

• Status Indication:Power-on, battery charging, network activity, or mode indicator lights in smartphones, tablets, laptops, and wearable devices.
• Backlighting:Utilizing its ultra-thin characteristics for edge-lit or direct-lit backlighting of symbols on small LCDs, keyboards, or control panels.
• Consumer Electronics:Decorative or functional lighting in audio equipment, gaming consoles, and home appliances.
• Industrial Control:Status and fault indicators on human-machine interfaces, sensors, and control units.

8.2 Circuit Design Considerations

Current Drive Method:LEDs are current-driven devices. To ensure uniform brightness when driving multiple LEDs in parallel,It is strongly recommendedto connect an independent current-limiting resistor in series with each LED. Relying on the natural I-V characteristics of LEDs to balance current in a simple parallel connection is not recommended, as slight variations in forward voltage will lead to significant differences in current and brightness between devices.

Electrostatic Discharge Protection:Semiconductor junctions are susceptible to damage from electrostatic discharge. Operational precautions must be observed: use grounded wrist straps and work surfaces, store components in anti-static materials, and use ionizers to neutralize static charges that may accumulate on plastic lenses during handling.

8.3 Gudanar da Zafi

Despite their small size, LEDs generate heat at the junction. Power dissipation limits and current derating factors are directly related to thermal performance. Care must be taken with PCB layout in high ambient temperature environments or when driven with high current. Using sufficient copper area connected to the LED terminals helps conduct heat away from the device to the PCB, maintaining a lower junction temperature and ensuring long-term reliability.

9. Kwatancen Fasaha da Bambance-bambance

The primary differentiation of this LED lies in itsUltra-low profile与High brightness enabled by AlInGaP technologyThe combination. Compared to older technologies like gallium phosphide, aluminum indium gallium phosphide offers significantly higher luminous efficiency, producing brighter light output at the same drive current. Compared to some other ultra-thin packages, the use of standard EIA pad patterns ensures broad compatibility with existing PCB designs and assembly processes, requiring no special tools. The wide viewing angle of 130 degrees is another advantageous feature, suitable for applications where indicator lights need to be visible from off-axis angles.

10. Tambayoyi da Amsoshi na Kowa

10.1 Menene bambanci tsakanin Peak Wavelength da Dominant Wavelength?

Peak Wavelength:_P):The specific wavelength at which the LED's optical power output physically reaches its maximum. It is a property of the semiconductor material and epitaxial layers.Babban tsawon zango:_d):A calculated value representing the wavelength of monochromatic light that, according to human eye color perception, matches the color of the LED's actual broad-spectrum output. The dominant wavelength is the parameter that defines the "color" for specification and binning purposes._dis the parameter that defines the "color" (e.g., green) for specification and binning purposes.

10.2 Me yasa kowane LED da aka haɗa a layi daya yana buƙatar resistor a jere?

LEDs have a non-linear I-V characteristic. When two LEDs are directly connected in parallel to a voltage source, a small difference in forward voltage will cause a large difference in current. The LED with a slightly lower forward voltage will disproportionately draw more current, becoming brighter and potentially overheating, while the other remains dimmer. Adding a series resistor for each LED provides negative feedback, stabilizing the current and ensuring brightness matching despite differences in forward voltage._F)—common due to manufacturing variations—will cause a large difference in current when two LEDs are connected directly in parallel to a voltage source. The LED with the slightly lower V_Fwill draw disproportionately more current, becoming brighter and potentially overheating, while the other remains dim. A series resistor for each LED provides negative feedback, stabilizing the current and ensuring matched brightness despite V_F variations.

10.3 Zan iya amfani da mafi girman kwararar na yau da kullun na milliamperes 30 don tuka wannan LED?

Yes, but the thermal environment must be carefully considered. At 30mA and a typical forward voltage of 2.0V, the power dissipation is 60mW, which is close to the absolute maximum of 75mW. Furthermore, the current must be derated for ambient temperatures above 25°C. At 30mA, there is very little margin. For reliable long-term operation, it is often prudent to drive the LED at a lower current, such as 5mA or in the 10-20mA range, which still provides good brightness while significantly reducing thermal stress and improving lifetime._Fof 2.0V, the power dissipation is 60mW, which is close to the absolute maximum of 75mW. Furthermore, the current must be derated for ambient temperatures above 25°C. At 30mA, there is very little margin. For reliable long-term operation, it is often prudent to drive the LED at a lower current, such as the 5mA or 10-20mA range, which still provides good brightness while significantly reducing thermal stress and improving lifetime.

10.4 Yaya mahimmanci tsarin gasa kafin gyaɗa?

It is very critical if the component has been exposed to ambient humidity outside its sealed moisture barrier bag for longer than the specified time. Plastic packages absorb moisture. During the rapid heating of reflow soldering, this trapped moisture can vaporize rapidly, causing internal delamination, package or lens cracking, or bond wire breakage—a failure known as the "popcorn" effect. Baking at 60°C for 24 hours safely drives out this absorbed moisture, preventing such damage.

11. Nazarin Shari'ar Zane

Scenario:Design a status indicator light for a new ultra-thin Bluetooth speaker. The indicator must be bright enough in daylight, have a wide viewing angle, and fit within a housing with a total thickness of less than 4 millimeters.

Component Selection:The LTST-C191KGKT-5A was chosen primarily for its 0.55mm height, allowing ample space for the housing wall and diffuser. The AlInGaP technology ensures sufficient brightness. The 130-degree viewing angle means the light is visible from almost any angle around the speaker.

Circuit Design:The LED is driven by a GPIO pin from the system's microcontroller, outputting 3.3 volts. Calculate the series resistor. Targeting a drive current of 10mA for a good balance between brightness and power consumption/heat: R = (Supply Voltage - Forward Voltage) / Forward Current. Using a typical forward voltage of 2.0 volts, R = (3.3V - 2.0V) / 0.01A = 130 ohms. On the PCB, a standard 130Ω resistor is placed in series with the LED._source- V_F) / I_F. Using a typical V_Fof 2.0V, R = (3.3V - 2.0V) / 0.01A = 130 Ohms. A standard 130Ω resistor is placed in series with the LED on the PCB.

PCB Layout:Use the pad layout recommended in the datasheet. Enhance heat dissipation by connecting the cathode pad to a small area of copper pour on the PCB, as the ambient temperature inside the speaker enclosure may rise during operation.

Assembly:LEDs are ordered on tape-and-reel for automated assembly. Provide the contract manufacturer with the lead-free reflow soldering profile from the datasheet to ensure proper soldering without thermal damage.

12. Technical Principles

LED yana dogara da semiconductor p-n junction da aka yi da aluminum indium gallium phosphide. Lokacin da aka yi amfani da ƙarfin lantarki mai kyau, electrons daga yankin n-type da kuma ramuka daga yankin p-type ana shigar da su cikin yankin aiki, inda suke haɗuwa. Wannan tsarin haɗuwa yana sakin makamashi a cikin nau'in photon. Takamaiman tsawon raƙuman hasken da aka fitar yana ƙayyade ta hanyar makamashin band-gap na kayan semiconductor, wanda aka ƙera ta hanyar daidaita adadin aluminum, indium, gallium da phosphorous yayin girma crystal. Aluminum indium gallium phosphide yana da inganci musamman wajen samar da haske na jeri na ja, orange, rawaya da kore. "Ruwa mai tsabta" ruwan tabarau yawanci ana yin su da epoxy ko silicone, ana gyara su kai tsaye a saman guntu da igiyoyin haɗin gwiwa, suna ba da kariyar muhalli, tallafin injiniya da gyaran gani, don cimma kusurwar gani da ake buƙata.

13. Industry Trends

Trends na LED mai nuna alama sun ci gaba da tafiya zuwaƘananan ƙira和Mafi ingancici gaba. Tsayin kunshe yana ci gaba da raguwa don samar da ƙananan samfuran ƙarshe. A lokaci guda, kuma ana tafiya zuwa ga mafi haske, don cimma matakin haske da ake buƙata a ƙananan ƙarfin tuƙi, don haka adana ikon tsarin da sauƙaƙe ƙirar zafi. Yayin da aluminum indium gallium phosphide ke da rinjaye a cikin bakan kore-rawaya-ja na keɓaɓɓen alamun, fasahar indium gallium nitride ta fi yadu a cikin shuɗi, fari da kore na gaskiya.