LTST-C19GD2WT Full-Color SMD LED Datasheet - Size 3.2x2.8x0.4mm - Voltage 2.0-3.8V - Power 0.075-0.08W - Technical Documentation

1. Product Overview

LTST-C19GD2WT is a full-color surface-mount device (SMD) LED designed for modern electronic applications requiring compact, multi-color indication or illumination. This device integrates three independent semiconductor light sources within an ultra-thin package, capable of producing a broad color spectrum by individually or collectively controlling the red, green, and blue (RGB) elements.

The core advantages of this device lie in its extremely small footprint, standardized EIA package geometry, and compatibility with high-volume automated assembly processes, including infrared (IR) and vapor phase reflow soldering. It is classified as a green product, compliant with RoHS (Restriction of Hazardous Substances) standards, suitable for environmentally conscious designs. Its primary target markets include consumer electronics, instrument panels, decorative lighting, status indicators in communication equipment, and backlight modules where space is limited and color flexibility is required.

2. Cikakken Bayanin Sigogi na Fasaha

2.1 Matsakaicin Matsakaicin Matsaloli

These ratings define the stress limits that could cause permanent damage to the device. To ensure long-term reliable performance, operation at or near these limits is not recommended.

• Power Dissipation (Pd):Varies by color diode: 80 mW for blue and green, 75 mW for red. This parameter indicates the maximum power that the LED junction can safely dissipate as heat at an ambient temperature (Ta) of 25°C.
• Peak Forward Current (I_F(PEAK)):Specified at 1/10 duty cycle, 0.1ms pulse width. Blue/Green: 100 mA, Red: 80 mA. This rating is critical for pulsed operation (e.g., in multiplexed displays).
• DC Forward Current (I_F):Two conditions are specified.Note 1:Maximum value for driving each color individually (Blue: 20mA, Red: 30mA, Green: 20mA).Note 2:The maximum value for simultaneously driving all three colors (red, green, blue: 10mA each). This distinction is crucial for circuit design to prevent thermal overstress.
• Derating:As ambient temperature increases, the DC forward current must be linearly reduced from its value at 25°C. The derating factor is 0.25 mA/°C for blue/green and 0.4 mA/°C for red.
• Reverse voltage (V_R):All colors are 5V. Exceeding this voltage under reverse bias may cause junction breakdown.
• Temperature range:Operating temperature: -20°C to +80°C. Storage temperature: -30°C to +100°C.
• Soldering conditions:Can withstand infrared reflow soldering at 260°C for 5 seconds.

2.2 Halayen Lantarki da Na'urar Gani

These are typical performance parameters measured under Ta=25°C and specified test conditions.

• Luminous Intensity (I_V):At I_F=20mA, measured in millicandelas (mcd). Typical values: Blue: 40.0 mcd, Red: 100.0 mcd, Green: 150.0 mcd. Minimum values ensure baseline brightness.
• Viewing Angle (2θ_1/2):Yawanci 130 digiri ne. Wannan faffadan kallon shine siffar ruwan tabarau mai watsawa, yana ba da faffadan, daidaitaccen rarraba haske, maimakon ƙunƙun katako.
• Kololuwar fitar da tsayin raƙuman ruwa (λ_P):Tsayin raƙuman ruwa lokacin da fitarwa na bakan ya kai matsakaicin ƙima. Ƙimar al'ada: Blue: 468 nm, Red: 632 nm, Green: 520 nm.
• Babban tsayin raƙuman ruwa (λ_d):An samo shi bisa ga taswirar launi na CIE, yana wakiltar launin fahimta. Kewayon: Blue: 465-477 nm, Red: 618-630 nm, Green: 519-540 nm.
• Rabin nisa na layin bakan (Δλ):Bandwidth lokacin da ƙarfin fitar da haske ya ragu zuwa rabin matsakaicin ƙima. Ƙimar al'ada: Blue: 26 nm, Red: 17 nm, Green: 35 nm. Ƙunƙuntar faɗin yana nuna mafi tsantsar launin bakan.
• Ƙarfin lantarki na gaba (V_F):At I_F=20mA ƙimar al'ada: Blue: 3.5V, Red: 2.0V, Green: 3.5V (matsakaicin ƙimomi bi da bi: 3.8V, 2.4V, 3.8V). V na LED ja_FYa yi ƙasa saboda bambancin kayan semiconductor dinsa (Red: AlInGaP, Blue/Green: InGaN).
• Kwararar koma baya (I_R):A cikin V_R=5V ya zama matsakaicin 10 µA, yana nuna ingancin haɗin gwiwa mai kyau.

3. Bayanin Tsarin Rarraba

Wannan samfurin yana amfani da tsarin rarrabawa, yana rarraba LED bisa ƙarfin haskensa, don tabbatar da daidaito a cikin rukuni. Kowane matakin ƙarfin yana da iyakar +/-15%.

• Matakin ƙarfin haske mai shuɗi:N (28.0-45.0 mcd), P (45.0-71.0 mcd), Q (71.0-112.0 mcd).
• Matakin ƙarfin haske mai ja:Q (71.0-112.0 mcd), R (112.0-180.0 mcd).
• Green luminous intensity bin:R (112.0-180.0 mcd), S (180.0-280.0 mcd), T (280.0-450.0 mcd).

The system allows designers to select devices that meet specific brightness requirements for color mixing or uniform appearance in arrays.

4. Bincike akan Lankwila Ayyuka

Although specific graphical curves (Figure 1, Figure 6) are referenced in the datasheet, their meaning is standard for LED technology.

• I-V (Current-Voltage) characteristics:LED is a diode with an exponential I-V relationship. Forward voltage (V_F) It has a negative temperature coefficient, meaning it slightly decreases as the junction temperature rises.
• Luminous Intensity vs. Forward Current:In the normal operating range, intensity is roughly proportional to the forward current. However, at extremely high currents, efficiency may decrease due to thermal effects.
• Luminous Intensity vs. Ambient Temperature:Light output typically decreases as ambient temperature (and junction temperature) increases. This is particularly important for high-power or high-density applications.
• Spectral Distribution:Each color of LED emits light at its peak wavelength (λ_P) is the characteristic bell-shaped curve of light. The full width at half maximum (Δλ) defines the width of the curve.

5. Bayanin Injiniya da Kunshewa

The device features an ultra-thin profile with a height of only 0.40 mm. It conforms to the EIA standard package outline, facilitating compatibility with industry-standard pick-and-place machines and solder paste stencils.

• Pin Assignment:Pin 1: InGaN blue, Pin 2: AlInGaP red, Pin 3: InGaN green. The lens is a white diffused type, which helps mix light from the individual chips to produce a more uniform color mix when viewed off-axis.
• Package Dimensions:Detailed mechanical drawings specify length, width, lead pitch, and tolerances (typically ±0.10 mm).
• Recommended Land Pattern:Recommended land patterns for PCB design are provided to ensure reliable solder joint formation and mechanical stability. The recommended solder paste stencil thickness is a maximum of 0.10mm.

6. Jagorar Walda da Haɗawa

6.1 Lankwilar Zazzabi na Walda Baya

An ba da shawarar tsarin zazzabi guda biyu na walda mai gudana ta infrared (IR): ɗaya don aikin walda na al'ada (tin-lead), ɗaya kuma don aikin walda mara gubar. Tsarin walda mara gubar an tsara shi musamman don amfani da man walda na SnAgCu (tin-azurfa-jar karfe), kuma ya dace da mafi girman wurin narkewa. Muhimman sigogi sun haɗa da yankin dumama, lokacin da ya wuce layin ruwa, mafi girman zazzabi (har zuwa 260°C) da lokacin riƙe mafi girman zazzabi.

6.2 General soldering conditions

• Walda Mai Gudana:Dumama: 120-150°C, Lokacin dumama: iyakar daƙiƙa 120, Mafi girman zazzabi: iyakar 260°C, Lokacin mafi girman zazzabi: iyakar daƙiƙa 5.
• Walda Mai Kalaman Igwa:Preheating: Maximum 100°C, up to 60 seconds. Solder wave: Maximum 260°C, up to 10 seconds.
• Hand Soldering (Soldering Iron):Temperature: Maximum 300°C, Time: Maximum 3 seconds (only once).

6.3 Storage and handling

• Storage:It is recommended not to exceed 30°C and 70% relative humidity. LEDs removed from their original moisture barrier packaging should undergo reflow soldering within one week. For longer-term storage, use a sealed container with desiccant or a nitrogen environment. Devices stored outside the packaging for more than one week should be baked at approximately 60°C for at least 24 hours before assembly to remove absorbed moisture and prevent the "popcorn" effect during reflow soldering.
• Cleaning:Use only the specified solvent. For cleaning, immerse in ethanol or isopropanol at room temperature for no more than one minute. Unspecified chemicals may damage the plastic package.
• ESD (Electrostatic Discharge) Precautions:LEDs are sensitive to ESD and surge damage. Handling recommendations include using a wrist strap or anti-static gloves and ensuring all equipment is properly grounded.

7. Packaging and ordering information

The LTST-C19GD2WT is supplied in tape and reel packaging suitable for automated assembly equipment.

• Tape Specifications:8mm tape width.
• Reel Specifications:Reel dengan diameter 7 inci.
• Kuantitas:5000 keping per reel standar. Untuk sisa pesanan, jumlah kemasan minimum adalah 500 keping.
• Kualitas Kemasan:Memenuhi standar ANSI/EIA 481-1-A-1994. Kantong komponen kosong disegel dengan cover tape. Jumlah maksimum komponen yang hilang secara berurutan dalam reel tape adalah dua.

8. Application recommendations

8.1 Yanayin Aikace-aikace na Al'ada

This LED is suitable for general electronic devices, including but not limited to: status indicators on consumer devices (routers, printers, chargers), backlighting for small displays or icons, decorative accent lighting, and multi-color alert systems in office automation or communication equipment.

8.2 Zane na'urar motsa jiki

A key design consideration is that LEDs are current-driven devices. To ensure uniform brightness when driving multiple LEDs in parallel, it is strongly recommended to connecteachLED in series with a current-limiting resistor (Circuit Model A). Driving multiple LEDs directly from a voltage source through a single shared resistor in parallel (Circuit Model B) is discouraged. The variation in forward voltage (V_F) characteristics among individual LEDs—even from the same batch—will lead to uneven current distribution, resulting in significant brightness differences and potential overcurrent in some devices.

8.3 Gudanar da Zafi

Despite its low power, proper thermal management must be considered, especially when driving at maximum current or in high ambient temperatures. Adhere to the power dissipation and current derating specifications. Ensure the PCB layout provides sufficient copper area for heat dissipation, particularly if a thermal pad is specified in the package land pattern.

9. Kwatancin Fasaha da Bambance-bambance

Babban abin da ya bambanta wannan kayan aiki shineSiririn tsayi na 0.4mm, wanda yake da amfani sosai ga aikace-aikacen da ke da ƙarancin sarari kamar na'urorin nuni masu siriri ko na'urorin sawa, da kumaCimma cikakken haɗin RGB a cikin daidaitaccen kushin SMD guda ɗaya. Idan aka kwatanta da amfani da LED guda uku masu rabuwa, wannan hanyar haɗawa tana adana sararin allon, tana sauƙaƙa haɗawa, kuma tana inganta daidaiton haɗin launi saboda kusancin tushen haske a ƙarƙashin ruwan tabarau guda ɗaya na watsawa. Dacewar sa da tsarin sake kwararowar IR na al'ada ya sa ya zama mafita mai sauƙin shigarwa ga layukan samarwa na zamani na SMT.

10. Tambayoyin da Ake Yi Akai-akai (FAQ)

Q: Can I drive the red, green, and blue LEDs simultaneously at their respective DC maximum currents (20mA, 30mA, 20mA)?
A: No. The datasheet specifies two different DC maximum forward current conditions. When driving all three colors simultaneously,the maximum current for eachcolor is limited to 10mA (Note 2). This is a thermal limitation to prevent the total power dissipation within the tiny package from exceeding a safe level.

Q: Why is the forward voltage of the red LED (2.0V) lower than that of the blue and green LEDs (3.5V)?
A: This is due to the different semiconductor materials used. The red LED uses AlInGaP (aluminum indium gallium phosphide), which has a lower bandgap energy than the InGaN (indium gallium nitride) used for blue and green LEDs. A lower bandgap means a lower forward voltage is required to turn on and emit light.

Q: How can I generate white light using this RGB LED?
A: White light is produced by mixing the three primary colors (red, green, blue) at appropriate intensities. This typically requires a microcontroller or a dedicated LED driver IC to perform Pulse Width Modulation (PWM) on the current for each diode independently. By varying the duty cycle of each color, you can mix them to produce white light, as well as any color within the gamut defined by the specific wavelengths of the three LEDs.

Q: The datasheet mentions a "lead-free process" temperature profile. If my assembly is lead-free, must I use this?
A: Yes, it is highly recommended. Lead-free solder alloys (e.g., SAC305) typically have a higher melting point than traditional tin-lead solder. The recommended lead-free reflow profile is designed to achieve a sufficient peak temperature (while staying within the LED's 260°C, 5-second limit) to properly melt the solder paste and form reliable solder joints without subjecting the components to excessive thermal stress.

11. Nazarin Lamuran Zane

Scenario: Designing a compact status indicator for a smart home hub.The device required a single multi-color LED to indicate network status (red for error, green for connected, blue for pairing mode, white for normal operation). The LTST-C19GD2WT was selected for its ultra-low profile (suitable for narrow bezels) and integrated RGB capability.

Implementation:The LED is placed on the main PCB. A GPIO pin from the microcontroller is connected to each cathode (R, G, B) via a current-limiting resistor (calculated based on desired brightness and the LED's V_Fcalculation, e.g., 8mA per color when generating white light simultaneously). The anodes are connected to the supply voltage. The microcontroller firmware controls the pins to turn individual colors on/off or uses PWM to produce white and other hues. The 130-degree wide viewing angle ensures the indicator is visible from various angles in the room.

Key Design Review:Verify total power consumption (P = V_{F_R}*I_R+ V_{F_G}*I_G+ V_{F_B}*I_B) is within the 75-80mW limit at operating ambient temperature, apply derating if necessary. Ensure PCB layout follows recommended pad dimensions for reliable soldering.

12. Hanyoyin Aiki

The Light Emitting Diode (LED) is a semiconductor p-n junction device that emits light through a process called electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material within the active region. This recombination releases energy. In conventional diodes, this energy is released primarily as heat. In LED materials, the bandgap energy of the semiconductor causes a significant portion of this energy to be released as photons (light). The specific wavelength (color) of the emitted light is directly determined by the bandgap energy of the semiconductor material used. The AlInGaP material system produces red and amber light, while the InGaN system is used for blue, green, and, via phosphor coatings, white LEDs.

13. Trends na Fasaha

The SMD LED field continues to evolve towards higher efficiency (more lumens per watt), smaller package sizes, and higher integration. Trends related to components like the LTST-C19GD2WT include: developing thinner packages for next-generation flexible and foldable displays; improving color rendering and color gamut for more vivid and accurate color mixing; and integrating driver ICs or control logic ("smart LEDs") within the LED package itself to simplify system design. Furthermore, advancements in materials science aim to enhance reliability and maximum operating temperature range, extending applications to more demanding environments. The pursuit of energy efficiency across all electronics continues to drive reductions in operating current while maintaining or increasing light output.