SMD LED LTST-E683FGBW Datasheet - Orange/Green/Blue Tricolor - 20mA - 80mW - Technical Documentation

1. Product Overview

This document details the specifications of the surface-mount device (SMD) LED component model LTST-E683FGBW. This device is a multi-color LED component that integrates three independent light-emitting chips within a single package: an orange AlInGaP chip, a green InGaN chip, and a blue InGaN chip. The device is designed for automated assembly processes, is compatible with infrared reflow soldering, and is suitable for high-volume electronics manufacturing. Its diffused lens provides a wide viewing angle, enhancing visibility from different perspectives.

2. Detailed Technical Parameters

2.1 Absolute Maximum Ratings

The operating limits of the device are defined under the condition of an ambient temperature (Ta) of 25°C. Exceeding these ratings may cause permanent damage.

• Power Dissipation (Pd):Orange: 72 mW; Green/Blue: 80 mW. This parameter indicates the maximum power that the LED can safely dissipate as heat under continuous DC operation.
• Peak Forward Current (IFP):Orange: 80 mA; Green/Blue: 100 mA. This is the maximum allowable pulsed current, specified at 1/10 duty cycle, 0.1ms pulse width, suitable for brief high-intensity flashes.
• Direct forward current (IF):Orange: 30 mA; Green/Blue: 20 mA. This is the recommended maximum continuous forward current to ensure long-term reliable operation.
• Temperature range:Operating temperature: -40°C to +85°C; Storage temperature: -40°C to +100°C. These ranges define the environmental conditions the device can withstand during use and in inactive states.

2.2 Electrical and Optical Characteristics

Key performance indicators are measured at Ta=25°C and a standard test current (IF) of 20mA, unless otherwise specified.

• Luminous Intensity (Iv):Measured in millicandelas (mcd), it represents the perceived brightness of a light source. Typical ranges are 140-355 mcd for orange and blue LEDs, while green LEDs are brighter, ranging from 355-900 mcd. Measurements follow the CIE photopic response curve.
• Viewing Angle (2θ1/2):Typical value is 120 degrees. This is the full angle at which the luminous intensity drops to half of its axial peak, indicating a very wide emission pattern.
• Wavelength parameters:
  • Peak Wavelength (λP):Wavelength at which the spectral power distribution reaches its maximum. Typical values: Orange: 611 nm, Green: 518 nm, Blue: 468 nm.
  • Dominant Wavelength (λd):The single wavelength that perceptually matches the color of the LED. Typical values: Orange: 605 nm, Green: 525 nm, Blue: 470 nm. This value is derived from the CIE chromaticity diagram.
  • Spectral Half-Width (Δλ):The bandwidth of the emission spectrum at half of its maximum intensity. Typical values: Orange: 17 nm (narrow), Green: 35 nm, Blue: 25 nm.
• Forward Voltage (VF):The voltage drop across the LED when a specified current flows through it. Range: Orange: 1.8-2.4V; Green/Blue: 2.8-3.8V. Tolerance is +/- 0.1V. This is crucial for driver circuit design.
• Reverse Current (IR):At a reverse voltage (VR) of 5V, maximum is 10 μA. This device is not designed for reverse bias operation; this parameter is for leakage current characterization only.

3. Binning System Description

LED binning is based on luminous intensity measured at 20mA to ensure color and brightness consistency within production batches.

• Orange and Blue Binning:Using codes R2, S1, S2, T1, intensity ranges from 140.0 mcd (R2 minimum) to 355.0 mcd (T1 maximum).
• Green Bin:Using codes T2, U1, U2, V1, with a higher intensity range, from 355.0 mcd (T2 minimum) to 900.0 mcd (V1 maximum).
• Tolerance:Kowane matakin ƙarfi yana da ƙarancin kusan +/-11% a kan ƙimar da aka tsara, don la'akari da ƙananan canje-canje.

Masu zane-zane yakamata su ƙayyade lambar rarrabuwar da ake buƙata lokacin yin oda, don tabbatar da cewa aikace-aikacensu ya kai matakin haske da ake tsammani, musamman a cikin jerin LED masu yawa inda daidaito ke da muhimmanci.

4. Performance Curve Analysis

The datasheet references typical characteristic curves (not fully detailed in the provided excerpt). These commonly plotted curves include:

• I-V (Current-Voltage) curve:It shows the relationship between forward current and forward voltage for each color chip. It illustrates the exponential turn-on characteristic of the diode, which aids in selecting current-limiting resistors or designing constant-current drivers.
• Luminous Intensity vs. Forward Current:Illustrates how light output increases with current, typically showing an approximately linear relationship within the recommended operating range, with efficiency decreasing at extremely high currents.
• Luminous Intensity vs. Ambient Temperature:It shows that as the junction temperature increases, the light output will derate, which is crucial for thermal management in high-power or high ambient temperature applications.
• Spectral Distribution:Plot the relative radiant power versus wavelength for each LED, visually representing the peak wavelength, dominant wavelength, and spectral half-width.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This device complies with the EIA standard SMD package outline. All dimensions are in millimeters, with a general tolerance of ±0.2 mm unless otherwise specified. The detailed dimension drawing will show length, width, height, lead pitch, and lens geometry.

5.2 Pin Definitions

This tri-color LED uses a common-cathode or common-anode configuration (implied by the single package). The pinout is: Pin 1: Orange anode, Pin 3: Blue anode, Pin 4: Green anode (common cathode may be on Pin 2 and/or 5, conforming to the standard 4-pin RGB LED package). It must be verified against the detailed package drawing to ensure correct PCB layout.

5.3 Tape and Reel Packaging

Components are supplied in industry-standard embossed carrier tape, wound on 7-inch (178 mm) diameter reels for automated pick-and-place assembly.

• Carrier Tape Dimensions:Carrier tape width, pocket pitch, and pocket dimensions are specified to ensure compatibility with standard feeder equipment.
• Reel specifications:Standard 7-inch reels contain 2000 pieces. The minimum order quantity for remainder reels is 500 pieces.
• Cover tape:Empty pockets are sealed with top cover tape.
• Quality:Complies with ANSI/EIA-481 specification. The maximum number of consecutive missing components allowed in the carrier tape is two.

6. Welding and Assembly Guide

6.1 Reflow Soldering Temperature Profile

This device is compatible with infrared (IR) reflow soldering processes. It is recommended to use a lead-free soldering temperature profile that complies with the J-STD-020B standard.

• Preheat:150-200°C, maximum 120 seconds, to gradually heat the circuit board and activate the flux.
• Peak Temperature:Should not exceed 260°C. The time above liquidus (e.g., 217°C) should be controlled according to the solder paste manufacturer's recommendations.
• Soldering Time:The total time at peak temperature should be limited to a maximum of 10 seconds. Reflow soldering can be performed up to two times.

Attention:The optimal temperature profile depends on the specific PCB design, solder paste, and reflow oven. The JEDEC-based profile can serve as a general target.

6.2 Manual Soldering

If manual soldering is necessary, extreme caution must be exercised:

• Soldering iron temperature:Maximum 300°C.
• Soldering Time:Kowane ɗan'uwa ya fi tsayi daƙiƙa 3.
• Iyakance:A yi walda da hannu sau ɗaya kawai, don guje wa lalacewar zafi ga LED ko igiyoyin haɗin gwiwa.

6.3 Cleaning

Avoid using unspecified chemical cleaners as they may damage the LED epoxy resin lens or package. If cleaning is required after soldering:

• Use alcohol-based solvents, such as ethanol or isopropanol.
• Soak the LED at room temperature.
• Limit the soaking time to within 1 minute.

6.4 Storage and Operation

• Sealed Packaging:Store at ≤30°C and ≤70% relative humidity (RH). Shelf life is one year when stored in the original moisture barrier bag with desiccant.
• Opened Packaging:Components exposed to ambient air should be stored in an environment ≤30°C and ≤60% relative humidity. It is strongly recommended to complete the infrared reflow soldering process within 168 hours (7 days) after opening the moisture barrier bag to prevent moisture absorption, which may lead to "popcorn" phenomenon during reflow.
• Extended Storage (Opened):For storage exceeding 168 hours, place the components in a sealed container with desiccant or a nitrogen-purged dry box.
• Baking:Components stored outside their original packaging for more than 168 hours must be baked at approximately 60°C for at least 48 hours before soldering to remove absorbed moisture.

7. Application Suggestions

7.1 Typical Application Scenarios

This tri-color SMD LED is designed for general indicator and backlighting applications in consumer and industrial electronics that require multiple status colors from a single compact component. Examples include:

• Multi-state indicators on network equipment, routers, or servers (e.g., power/activity/error).
• Backlighting of buttons or icons on control panels, remote controls, or appliances.
• Decorative lighting or status displays in automotive interiors (non-critical functions).
• Portable electronic device status indicator.

Important Application Restrictions:The datasheet clearly states that these LEDs are suitable for "general electronic equipment." They are not certified for safety-critical applications where failure could endanger life or health, such as in aviation, medical life support, or traffic safety systems. For such applications, components with corresponding reliability certifications must be procured.

7.2 Design Considerations

• Current Limiting:Always use an external current-limiting resistor or constant-current driver for each color channel. Calculate the resistor value based on the supply voltage, the LED's forward voltage (VF, use the maximum value for safety), and the desired forward current (IF, which must not exceed the DC rating).
• Thermal Management:Although the power consumption is low, if operating at high ambient temperatures or maximum current, ensure sufficient PCB copper area or thermal vias to keep the junction temperature within limits and ensure long-term reliability and stable light output.
• PCB Pad Design:Follow the recommended pad layout in the package drawing of the specification to ensure proper solder joint formation and maintain mechanical stability during the reflow soldering process.
• ESD Protection:Although not explicitly stated, it is recommended to follow standard ESD handling precautions for semiconductor devices during assembly.

8. Technical Comparison and Differentiation

Although this single specification sheet does not provide a direct comparison with other models, the key differentiating features of this component can be inferred:

• Single Package Tri-Color:Integrates three independent colors, saving PCB space and assembly costs compared to using three separate monochromatic LEDs.
• Wide viewing angle (120°):The diffused lens provides omnidirectional visibility, superior to narrow-angle LEDs used for focused beams.
• High brightness green:Idan aka kwatanta da orange da shuɗi, kore chip yana ba da haske mai ƙarfi sosai (har zuwa 900 mcd), wataƙila don daidaita hasken kowane launi da aka fahimta saboda bambancin hankalin idon mutum.
• Ƙarfafan kunshe:Dacewa da infrared reflow soldering da kuma na'urar haɗawa ta atomatik yana nuna cewa an ƙera wannan kunshe don zamani, ingantaccen tsarin haɗin SMT.
• Standardized Binning:A well-defined binning structure enables predictable and consistent optical performance across production batches.

9. Frequently Asked Questions (Based on Technical Parameters)

Q1: Ina iya tuƙa duk launuka uku tare da matsakaicin ƙarfin lantarki na DC (orange 30mA, kore/blue 20mA) a lokaci guda?
A: A'a. Ba za a iya wuce matsakaicin jimlar yawan amfani da wutar lantarki (Pd) a cikin ƙididdiga ba. Yin aiki tare da matsakaicin ƙarfin lantarki a lokaci guda zai haifar da jimlar yawan amfani da wutar lantarki ta wuce iyakar 80mW na kayan aiki (wanda aka lissafta a matsayin VF*IF na kowane guntu sannan aka tara). Dole ne ku rage ƙarfin lantarki na aiki ko kuma ku yi amfani da aikin bugun jini, don ci gaba da kasancewa cikin iyakar jimlar Pd.

Q2: Menene bambanci tsakanin tsayin raƙuman koli da babban tsayin raƙuman?
A: Peak wavelength (λP) is the physical peak of an LED's emission spectrum. Dominant wavelength (λd) is a calculated value representing the perceived color hue on the CIE chart as a single wavelength. For monochromatic LEDs, they are typically close; for broader spectra (e.g., green), they may differ more significantly. λd is more relevant for color matching.

Q3: Why is the reverse current rating important if the LED is not used in reverse operation?
A: The IR rating (max 10 μA at 5V) is a leakage current specification. It ensures the device does not draw excessive current if a small reverse voltage is accidentally applied (e.g., during circuit transients or in multiplexed designs). This is a reliability parameter, not an operating condition.

Q4: How critical is the 168-hour floor life after opening the moisture barrier bag?
A: It is critical for reflow soldering. Moisture absorbed into the plastic package can rapidly vaporize during the high-temperature reflow cycle, causing internal delamination, cracks, or "popcorn" effect, leading to failure. Adhering to the 168-hour window or following a baking procedure is essential for yield and reliability.

10. Practical Design Cases

Scenario:Design a status indicator for a device using a 5V power rail. The indicator must show orange for "standby", green for "normal operation", and blue for "error". Only one color lights up at a time.

Design Steps:

1. Select Operating Current:For all colors, choose a safe standard value, such as 15mA, well below the DC maximum, to ensure longevity and reduce thermal load.
2. Calculate Current Limiting Resistor:
   • Don kari na lafiya, yi amfani da mafi girman ƙimar VF a cikin takardar ƙayyadaddun bayanai: Orange: 2.4V, Green: 3.8V, Blue: 3.8V.
   • Ƙarfin lantarki (Vs) = 5V. Dabara: R = (Vs - VF) / IF.
     • R_Orange = (5V - 2.4V) / 0.015A ≈ 173 Ω (amfani da daidaitaccen ƙimar 180 Ω).
     • R_green = (5V - 3.8V) / 0.015A ≈ 80 Ω (use 82 Ω standard value).
     • R_blue = (5V - 3.8V) / 0.015A ≈ 80 Ω (use 82 Ω standard value).
   • Recalculate actual current using standard resistor: I_orange = (5-2.4)/180 ≈ 14.4mA (safe).
3. Check power consumption:
   • Worst-case single LED power: P = VF * IF. Estimate using typical VF: P_green ≈ 3.3V * 0.0144A ≈ 47.5 mW, below the 80 mW limit for green/blue chips. Orange chip power is even lower. Since only one lights at a time, total package Pd is not exceeded.
4. PCB Layout:Place the LED and its three resistors close together. Use the pad layout recommended in the mechanical drawing. Ensure the correct pin definitions (1=orange, 3=blue, 4=green) are mapped to the drive circuit (e.g., microcontroller GPIO pins with series resistors).
5. Drive Circuit:Use microcontroller pins configured as open-drain or with series resistors to sink current to ground (if common cathode) or source current from the power supply (if common anode).

11. Introduction to Working Principles

A light-emitting diode (LED) is a semiconductor device that emits light through 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 in the active region. This recombination releases 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 used in the active region.

• Orange LED:Uses aluminum indium gallium phosphide (AlInGaP) semiconductor, whose band gap corresponds to red/orange/amber light.
• Green and blue LED:InGaN semiconductor is used. By adjusting the indium/gallium ratio, the bandgap can be tuned to emit blue, green, and cyan spectra. Achieving efficient green emission with InGaN is more challenging than blue, which is reflected in different performance characteristics (e.g., forward voltage, efficiency).

Three chips are mounted in a reflective cavity within the plastic package. A diffused epoxy resin lens encapsulates the chips, providing environmental protection, shaping the light output beam (120° viewing angle), and mixing light from individual chips when multiple chips are lit simultaneously to produce other colors (e.g., white, if phosphor is present, but not in this RGB device).

12. Trends in Technological Development

Teknolojia inayowakilishwa na kijenzi hiki iko katika mwelekeo mpana wa optoelektroniki:

• Uboreshaji wa ufanisi:Uboreshaji endelevu wa sayansi ya nyenzo na muundo wa chip unaoendelea kuongeza ufanisi wa mwanga wa LED (lumeni kwa kila watt), kuruhusu pato lenye mwangaza zaidi kwa umeme mdogo au kupunguza matumizi ya nguvu.
• Miniaturization:Although this is a standard package, the industry is moving towards smaller Chip Scale Package (CSP) LEDs to achieve ultra-compact designs, albeit often at the expense of thermal performance and ease of handling.
• Color Consistency Improvement:The advancement of epitaxial growth and binning processes has made the distribution of wavelength and intensity more concentrated, which is crucial for applications requiring consistent color appearance among multiple units.
• Integration:In addition to multi-chip single packages, the trend is to integrate LED driver ICs (constant current sources, PWM controllers) into the LED package itself, thereby simplifying circuit design.
• Reliability and Robustness:Enhanced packaging materials and construction techniques improve resistance to thermal cycling, humidity, and mechanical stress, extending operational life far beyond traditional limits and enabling LED use in more demanding environments.

This specific component exemplifies the mature, cost-effective application of LED technology for standard indicator purposes, balancing performance, reliability, and manufacturability.