LTST-C295TBKSKT Dual-Color SMD LED Datasheet - 0.55mm Ultra-Thin - Blue/Yellow - 20mA/30mA - Technical Documentation

1. Product Overview

This document details the specifications of the LTST-C295TBKSKT, a dual-color Surface Mount Device (SMD) LED. This component integrates two distinct LED chips within an extremely thin package, making it ideal for space-constrained applications requiring multiple indicator colors or status signals.

1.1 Core Advantages and Target Market

Babban fa'idodin wannan LED sun haɗa da siririn siffar sa na 0.55mm, wanda ya sa ya zama mai dacewa don haɗawa cikin na'urorin amfani masu siriri, na'urorin ɗaukar kayayyaki, da ƙirar PCB na zamani masu ƙarfi. Ya haɗa da guntu na InGaN don haske shuɗi da guntu na AlInGaP don haske rawaya. Samfurin ya bi ka'idodin ROHS kuma ana iya rarrabe shi azaman "Samfuri mai kore". Ɗayan ƙirar sa ya dace da na'urorin saka ta atomatik da daidaitattun hanyoyin IR reflow soldering, wanda ya dace da samarwa mai yawa. Kasuwar manufa ta ƙunshi na'urorin lantarki na gabaɗaya, gami da na'urorin sarrafa ofis, na'urorin sadarwa, da na'urorin gida waɗanda ke buƙatar nuni mai aminci mai launi biyu.

2. In-depth Technical Parameter Analysis

Halayen aiki an ayyana su a daidaitattun yanayin zafin yanayi (Ta=25°C).

2.1 Absolute Maximum Ratings

Waɗannan ƙididdiga sun ayyana iyakokin yanayi waɗanda zasu iya haifar da lalacewa ta dindindin ga na'urar, kuma ba a amfani da su don aiki na ci gaba ba.

• Power consumption:Blue light: 76 mW, Yellow light: 75 mW.
• Peak forward current (1/10 duty cycle, 0.1ms pulse):Blue light: 100 mA, Yellow light: 80 mA.
• DC forward current (continuous):Blue light: 20 mA, Yellow light: 30 mA. This is the recommended operating current for each color.
• Operating temperature range:-20°C to +80°C.
• Zangar yanayin zafi:-30°C zuwa +100°C.
• Yanayin haɗa infrared:Yana iya jurewa zafin kololuwar 260°C na dakika 10, wannan ya dace da buƙatun aikin haɗa maras gubar na yau da kullun.

2.2 Electrical and Optical Characteristics

Waɗannan sigogi suna ayyana aikin da ake tsammani a ƙarƙashin yanayin aiki na yau da kullun (IF = 20 mA).

• Ƙarfin haske (Iv):
  • Blue light: Minimum 18.0 mcd, typical value unspecified, maximum 180 mcd.
  • Yellow light: Minimum 28.0 mcd, typical value unspecified, maximum 180.0 mcd.
  The broad range indicates the use of a binning system (see Section 3).
• Viewing angle (2θ1/2):Both colors are typically 130 degrees, providing a wide diffused light pattern.
• Peak emission wavelength (λP):Blue: 468 nm (typical), Yellow: 591 nm (typical).
• Dominant wavelength (λd):Blue light: 470 nm (typical), Yellow light: 589 nm (typical). This is the color perceived by the human eye.
• Spectral Line Half-Width (Δλ):Blue light: 25 nm (typical), Yellow light: 15 nm (typical). The spectral bandwidth of yellow light is narrower.
• Forward Voltage (VF):Blue light: maximum 3.80V at 20mA, Yellow light: maximum 2.40V at 20mA. This voltage difference between LEDs must be considered when designing the drive circuit.
• Reverse Current (IR):At VR = 5V, both have a maximum of 10 μA.Important Note:This device is not designed for reverse bias operation; this test condition is only used to characterize leakage current.

3. Grading System Description

To ensure color and brightness consistency in production, LEDs are sorted into different bins based on their measured performance.

3.1 Luminous Intensity Grading

The luminous intensity of each color is classified into specific code ranges, with a tolerance of ±15% within each bin.

• Blue LED Bins (mcd @ 20mA):M (18.0-28.0), N (28.0-45.0), P (45.0-71.0), Q (71.0-112.0), R (112.0-180.0).
• Yan LED matsayi (mcd @ 20mA):N (28.0-45.0), P (45.0-71.0), Q (71.0-112.0), R (112.0-180.0).

Wannan tsarin yana ba masu zane damar zaɓar matakin haske da ya dace bisa bukatun aikace-aikacensu (daga ƙananan haske mai nuna alama zuwa babban haske mai nuna yanayi).

4. Performance Curve Analysis

Ko da yake takamaiman lanƙwan zane (misali Hoto 1, Hoto 5) an ambata a cikin takardar ƙayyadaddun bayanai, ana iya siffanta halayensu na yau da kullun bisa ilimin kimiyyar semiconductor.

4.1 Current-Voltage (I-V) Characteristics

Forward voltage (VF) is not constant but increases with the rise in forward current (IF). Blue LEDs based on InGaN technology will exhibit a higher VF (typically around 3.2V) at their operating current compared to yellow AlInGaP LEDs (typically around 2.0V). The driving circuit should use a current-limiting resistor or a constant current driver to prevent thermal runaway.

4.2 Temperature Dependence

LED performance is sensitive to temperature. Typically, the forward voltage (VF) decreases with increasing junction temperature (negative temperature coefficient). Conversely, luminous intensity generally decreases with rising temperature. The specified operating range of -20°C to +80°C ensures reliable operation within these variations.

4.3 Spectral Distribution

Peak wavelength and dominant wavelength are specified. The emission center for blue LEDs is around 468-470 nm, while for yellow LEDs it is around 589-591 nm. The half-width value indicates spectral purity; the narrower 15nm bandwidth of the yellow LED suggests its yellow color is more saturated than the blue LED's 25nm bandwidth.

5. Mechanical and Packaging Information

5.1 Package Dimensions and Pin Assignment

This device conforms to the EIA standard SMD package dimensions. Its key characteristic is a height of 0.55 mm. The pin assignment for the bi-color LED is: pins 1 and 3 are for the anode/cathode of the blue LED, and pins 2 and 4 are for the anode/cathode of the yellow LED. The exact pin definition (which pin is anode or cathode) must be confirmed from the package diagram to ensure correct PCB layout.

5.2 Pad Layout

The datasheet contains recommended land pattern dimensions. Adhering to these recommendations is crucial for achieving reliable solder joints, proper self-alignment during reflow soldering, and managing thermal stress. The land pattern design considers the thermal mass of the package and the need to establish robust electrical and mechanical connections.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

Yana ba da cikakken shawarar lanƙwasa infrared da aka keɓance don aikin haɗin gwiwar maras gubar. Maɓalli maɓalli sun haɗa da: yankin preheating (150-200 ° C), ƙayyadaddun zafi zuwa mafi girman zafin jiki na 260 ° C, da lokacin sama da layin ruwa (TAL) don tabbatar da samar da ingantaccen haɗin gwiwa. Kayan aikin bai kamata su wuce dakika 10 a 260 ° C ba. Wannan lanƙwasa ya dogara ne akan ma'aunin JEDEC don tabbatar da dogaro.

6.2 Hand Soldering

Idan dole ne a yi haɗin hannu, yakamata a yi amfani da ƙarfe mai ƙarfe wanda bai wuce 300 ° C ba, kuma lokacin tuntuɓar kowane aiki yakamata a iyakance zuwa aƙalla dakika 3. Zafi mai yawa zai lalata LED guntu ko filastik.

6.3 Cleaning

Idan ana buƙatar tsaftacewa bayan haɗin gwiwa, kawai yakamata a yi amfani da kaushi da aka keɓance. Takaddun bayanai yana ba da shawarar nutsar da LED a cikin ethanol ko isopropyl alcohol a cikin yanayin zafi na yau da kullun ba fiye da minti ɗaya ba. Sinadarai da ba a bayyana ba na iya lalata kayan kunshe, haifar da canza launi, fashewa, ko rage fitar da haske.

6.4 Storage and Handling

ESD Prevention Measures:LEDs are sensitive to Electrostatic Discharge (ESD). Anti-static measures should be taken during handling, such as wearing an anti-static wrist strap and using grounded equipment.
Moisture Sensitivity:Devices are packaged in moisture barrier bags with desiccant. Once the original bag is opened, LEDs should be used within one week. If long-term storage outside the original packaging is required, they must be stored in a dry environment (≤30°C, ≤60% RH) or re-baked before soldering (approximately 60°C, 20 hours) to prevent "popcorn" effect during reflow soldering.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

LEDs are supplied in standard 8mm carrier tape, wound on 7-inch (178mm) diameter reels. Each reel contains 4000 pieces. This packaging is compatible with automatic pick-and-place machines used in high-speed PCB assembly lines. The carrier tape has a cover to protect the components.

8. Application Recommendations

8.1 Typical Application Scenarios

This bi-color LED is ideal for status indication requiring the communication of two states (e.g., power on/standby, charging status, network activity, error/warning signals). Its slim profile makes it a perfect choice for modern smartphones, tablets, ultra-thin laptops, wearable devices, and slim control panels.

8.2 Design Considerations

• Current Drive:Always connect a current-limiting resistor in series for each LED color. Calculate the resistor value based on the supply voltage (Vcc), the LED's forward voltage (VF), and the desired operating current (IF). Calculate separately due to the different VF values for blue and yellow light.
• Thermal Management:Although power consumption is low, ensuring sufficient PCB copper area around the thermal pad (if present) or traces aids in heat dissipation, thereby maintaining the LED's service life and stable light output.
• Optical Design:A 130-degree viewing angle provides wide visibility. An external lens or light guide may be required to focus the light.

9. Technical Comparison and Differentiation

The key differentiation of this product lies in combining two high-performance LED technologies (InGaN for blue, AlInGaP for yellow) in a single industry-standard, ultra-thin (0.55mm) package. Compared to using two separate monochromatic LEDs, this solution saves PCB space, reduces component count, and simplifies assembly. The high luminous intensity bin (up to 180 mcd) offers brightness competitive with many standard SMD LEDs.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 Can I drive both LED colors at full current simultaneously?

A'a, amma dole ne a yi la'akari da jimlar amfani da wutar lantarki da tasirin zafi. Tuƙawa tare da matsakaicin ƙarfin yanzu na DC (blue 20mA, yellow 30mA, jimlar 50mA) zai haifar da zafi. Tabbatar cewa yanayin yanayin aikace-aikace da tsarin PCB na iya sarrafa nauyin zafi na haɗin gwiwa, ba tare da wuce matsakaicin zafin jiki ba.

10.2 Why are the forward voltages different for blue and yellow light?

Ƙarfin lantarki na gaba shine ainihin sifa na tazarar band na kayan semiconductor. Tazarar band na InGaN (blue) ya fi na AlInGaP (yellow) fadi, yana buƙatar mafi girman ƙarfin lantarki don "tura" electrons ta hanyar junction, don haka samar da mafi girman makamashi (gajeriyar tsawon zango) na photons.

10.3 How to select the correct gear code?

Zaɓi bisa ga buƙatun daidaiton haske na aikace-aikace. Don rukunin alamun nuni, ƙayyadaddun ƙayyadaddun kewayon gear (misali, duk P gear) yana tabbatar da daidaiton bayyanar. Don aikace-aikace masu mahimmanci farashi kuma ba su da buƙatun cikakken haske, faffadan gear ko gauraye gear na iya zama abin karɓa.

11. Ayyukan ƙira da amfani na ainihi

Scenario: Dual-Status Indicator for Portable Chargers.The blue LED can indicate "Charging in Progress," and the yellow LED can indicate "Charging Complete." Designers will use the recommended pad dimensions for PCB layout. Design two independent drive circuits: one calculates the current-limiting resistor based on the VF of the blue LED (e.g., (5V - 3.2V)/0.02A = 90Ω), and the other calculates for the yellow LED (e.g., (5V - 2.0V)/0.03A ≈ 100Ω). A microcontroller will control transistors to switch each circuit. The slim package allows it to fit into the charger's thin housing.

12. Gabatarwar ƙa'idar aiki

An LED is a semiconductor diode. When a forward voltage is applied, electrons from the n-type material recombine with holes from the p-type material within the active region. This recombination releases energy in the form of photons (light). The color (wavelength) of the emitted light is determined by the bandgap energy of the semiconductor material used in the active region. InGaN chips produce blue light, and AlInGaP chips produce yellow light. The package includes a water-clear lens, which minimally alters the emitted color.

13. Trends na fasaha

The development of this component reflects broader trends in optoelectronics:Miniaturization(Thinner packaging),Multifunctional integration(Combining multiple chips/colors), andManufacturing compatibility(Compliant with automated, lead-free processes). Future trends may include thinner profiles, higher efficiency (more light output per mA), and integrating more than two colors or combining photodetectors within a single package.