SMD LED LTSA-G6SPVEKTU Datasheet - AlInGaP Red - 120° Viewing Angle - 1.90-2.65V @140mA - 530mW - English Technical Document

1. Product Overview

This document provides the complete technical specifications for the LTSA-G6SPVEKTU, a surface-mount device (SMD) light-emitting diode (LED). This component belongs to a family of LEDs designed in miniature packages optimized for automated printed circuit board (PCB) assembly processes and applications where space constraints are a primary concern. The device is constructed using Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor technology, which is known for producing high-efficiency red light emission.

The core design philosophy behind this LED is to offer a reliable, compact light source suitable for integration into modern electronic assemblies. Its package conforms to Electronic Industries Alliance (EIA) standard dimensions, ensuring compatibility with a wide range of automated pick-and-place machines used in high-volume manufacturing. A key feature is its compatibility with infrared (IR) reflow soldering processes, which is the standard method for attaching SMD components to PCBs. This makes it an ideal choice for replacing through-hole LEDs in new designs or for implementing lighting solutions in densely packed electronic devices.

The primary target market for this specific LED model is the automotive industry, particularly for non-critical accessory and interior lighting applications. Examples include dashboard indicator lights, button backlighting, or ambient lighting features. The component has undergone qualification testing with reference to the AEC-Q101 standard, which defines stress test qualification for discrete semiconductor components in automotive applications, indicating a focus on reliability under the demanding conditions found in vehicles.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the limits beyond which permanent damage to the device may occur. These values are specified at an ambient temperature (Ta) of 25°C and must not be exceeded under any operating condition.

• Power Dissipation (Pd): 530 mW. This is the maximum amount of electrical power that can be converted into heat and light within the LED chip without causing failure. Exceeding this limit risks overheating the semiconductor junction.
• Peak Forward Current (I_F(PEAK)): 400 mA. This is the maximum allowable instantaneous forward current, permissible only under pulsed conditions with a 1/10 duty cycle and a pulse width of 0.1 milliseconds. It is significantly higher than the continuous current rating.
• DC Forward Current Range (I_F): 5 mA to 200 mA. This defines the safe operating window for continuous DC current. The device requires a minimum of 5mA to achieve useful light output, while 200mA is the absolute maximum for continuous operation.
• Operating & Storage Temperature Range: -40°C to +110°C. The LED can function and be stored within this wide temperature range, which is essential for automotive applications that experience extreme environmental conditions.
• Infrared Soldering Condition: Withstands 260°C for 10 seconds. This parameter is critical for the assembly process, defining the peak temperature and time the LED package can tolerate during lead-free reflow soldering without degradation.

2.2 Thermal Characteristics

Thermal management is crucial for LED performance and longevity. These parameters describe how effectively heat is transferred away from the light-emitting junction.

• Thermal Resistance, Junction-to-Ambient (R_θJA): 50 °C/W (Typical). Measured on a standard FR4 PCB (1.6mm thick) with a 16mm² copper pad, this value indicates the temperature rise of the LED junction per watt of power dissipated, relative to the ambient air. A lower value is better.
• Thermal Resistance, Junction-to-Solder Point (R_θJS): 30 °C/W (Typical). This is often a more useful metric for design, as it describes the thermal path from the junction to the PCB solder pads. It highlights the importance of PCB layout and thermal vias in managing heat.
• Maximum Junction Temperature (T_J): 125 °C. The temperature of the semiconductor junction itself must never exceed this limit during operation.

2.3 Electrical & Optical Characteristics

These are the key performance parameters measured at a standard test condition of 25°C ambient temperature and a forward current (I_F) of 140mA, unless otherwise noted.

• Luminous Intensity (I_V): 4.5 cd (Min) to 11.2 cd (Max). This is a measure of the perceived power of light emitted in a specific direction. The value is measured using a sensor filtered to match the human eye's photopic response curve (CIE standard). The wide range indicates the device is available in different brightness bins.
• Viewing Angle (2θ_1/2): 120 degrees (Typical). This is the full angle at which the luminous intensity drops to half of its value measured on-axis (0°). A 120° angle provides a very wide beam, suitable for area illumination or indicators that need to be visible from a broad perspective.
• Peak Emission Wavelength (λ_P): 631 nm (Typical). This is the wavelength at which the spectral power distribution of the emitted light reaches its maximum. It is a physical property of the AlInGaP material.
• Dominant Wavelength (λ_d): 620 nm to 629 nm. This is derived from the CIE chromaticity diagram and represents the single wavelength that best describes the perceived color of the light. It is the parameter used for color binning. The tolerance is ±1 nm.
• Spectral Line Half-Width (Δλ): 18 nm (Typical). This is the width of the emission spectrum at half of its maximum power. A narrower half-width indicates a more spectrally pure, saturated color.
• Forward Voltage (V_F): 1.90 V (Min) to 2.65 V (Max) @ 140mA. This is the voltage drop across the LED when operating. It varies with current and temperature and is binned into specific ranges for design consistency. Tolerance is ±0.1V.
• Reverse Current (I_R): 10 μA (Max) @ V_R=12V. LEDs are not designed for reverse bias operation. This parameter is tested for quality assurance only; applying reverse voltage in a circuit must be prevented, typically with a series diode or proper circuit design.

3. Bin Ranking System Explanation

To ensure consistency in mass production, LEDs are sorted (binned) based on key parameters after manufacture. The LTSA-G6SPVEKTU uses a three-code system (e.g., F/EA/1) printed on the packaging label.

3.1 Forward Voltage (V_f) Rank

Bins the LED based on its forward voltage drop at 140mA. Designers select a bin to ensure consistent brightness and current draw when multiple LEDs are connected in parallel.

• Bin C: 1.90V – 2.05V
• Bin D: 2.05V – 2.20V
• Bin E: 2.20V – 2.35V
• Bin F: 2.35V – 2.50V
Bin G: 2.50V – 2.65V

3.2 Luminous Intensity (I_v) Rank

Bins the LED based on its optical output power at 140mA. This allows designers to select a brightness level suitable for the application.

• Bin DA: 4.5 cd – 5.6 cd
• Bin EA: 7.1 cd – 9.0 cd
• Bin EB: 9.0 cd – 11.2 cd

3.3 Dominant Wavelength (W_d) Rank

For this specific part number, all units fall into a single wavelength bin to ensure color consistency.

• Bin 1: 620 nm – 629 nm (Tolerance ±1 nm)

4. Performance Curve Analysis

The datasheet provides typical performance curves which are essential for understanding device behavior under non-standard conditions. These curves are graphical representations of how key parameters change.

4.1 Relative Luminous Intensity vs. Forward Current

This curve (Fig. 1 in the datasheet) shows how light output increases with forward current. It is typically non-linear; the increase in brightness diminishes as current rises due to efficiency droop and increased thermal effects. This curve is vital for selecting the operating current to achieve a desired brightness while maintaining efficiency and reliability.

4.2 Spatial Distribution (Beam Pattern)

The polar diagram (Fig. 2) visually represents the 120-degree viewing angle. It shows the luminous intensity as a function of the angle from the central axis. The pattern for this LED is typically Lambertian or near-Lambertian, meaning intensity is approximately proportional to the cosine of the viewing angle, resulting in a wide, even illumination suitable for many indicator and lighting applications.

4.3 Forward Voltage vs. Forward Current

This curve illustrates the relationship between the voltage across the LED and the current flowing through it. It demonstrates the diode's exponential I-V characteristic. The curve shifts with temperature; forward voltage typically decreases as junction temperature increases for a given current. This is important for constant-current driver design.

4.4 Relative Luminous Intensity vs. Ambient Temperature

This curve shows how light output decreases as the ambient (and consequently, junction) temperature increases. LEDs are sensitive to temperature, and light output can drop significantly at high temperatures. Understanding this derating is critical for applications operating in hot environments, such as automotive interiors, to ensure sufficient brightness is maintained under all conditions.

5. Mechanical & Package Information

5.1 Package Dimensions

The LED comes in a standard SMD package. The key mechanical features include:

• Lens Color: Water Clear. The encapsulating lens is transparent, allowing the native red color of the AlInGaP chip to be seen.
• Source Color: AlInGaP Red.
• Polarity Identification: The anode lead frame also serves as the primary heat sink for the LED. Proper identification of the anode and cathode pads on the PCB footprint is crucial for correct electrical and thermal performance.
• Tolerance: All linear dimensions have a tolerance of ±0.2 mm unless otherwise specified on the detailed package drawing provided in the datasheet.

5.2 Recommended PCB Attachment Pad Layout

The datasheet includes a detailed drawing of the recommended copper pad pattern on the PCB for infrared reflow soldering. Adhering to this layout is critical for several reasons:

• Reliable Solder Joint Formation: The pad size and shape ensure proper solder wetting and fillet formation during reflow.
• Thermal Management: The pads, particularly the anode pad which is connected to the internal heat sink, act as a thermal conduit to transfer heat from the LED junction into the PCB copper layers. A larger pad or connection to internal ground planes improves heat dissipation.
• Mechanical Stability: The correct pad design ensures the component is held securely to the board after soldering.

6. Soldering & Assembly Guidelines

6.1 IR Reflow Soldering Profile

The device is qualified for lead-free (Pb-free) soldering processes. The datasheet specifies a recommended reflow profile compliant with J-STD-020. Key parameters include:

• Preheat: Ramp-up to 150-200°C.
• Soak/Preheat Time: Maximum of 120 seconds to allow for temperature stabilization across the PCB.
• Peak Temperature: Maximum of 260°C.
• Time Above Liquidus (TAL): The time within 5°C of the peak temperature should be limited to a maximum of 10 seconds. The component should not be subjected to more than two reflow cycles.

Following this profile prevents thermal shock to the LED package and the internal wire bonds, ensuring long-term reliability.

6.2 Hand Soldering (If Necessary)

If manual rework is required, extreme caution is needed:

• Iron Temperature: Maximum 300°C.
• Soldering Time: Maximum 3 seconds per solder joint.
• Limit: Hand soldering should be performed only once on a given LED to avoid cumulative thermal damage.

6.3 Storage & Handling

This product is classified as Moisture Sensitivity Level (MSL) 2 per JEDEC J-STD-020.

• Sealed Package: When in the original moisture-proof bag with desiccant, the LEDs should be stored at ≤30°C and ≤70% Relative Humidity (RH) and used within one year.
• Opened Package: Once the bag is opened, components should be stored at ≤30°C and ≤60% RH. It is recommended to complete IR reflow within one year of opening.
• Baking: If LEDs are stored out of their original packaging for more than one year, they must be baked at approximately 60°C for at least 48 hours before soldering to remove absorbed moisture and prevent \"popcorning\" (package cracking) during reflow.

6.4 Cleaning

If post-solder cleaning is necessary, only specified solvents should be used:

• Recommended: Ethyl alcohol or isopropyl alcohol.
• Method: Immersion at normal room temperature for less than one minute.
• Warning: Unspecified chemical cleaners may damage the LED's plastic package or lens, leading to discoloration, cracking, or reduced light output.

7. Packaging & Ordering Information

7.1 Tape and Reel Specifications

The LEDs are supplied in industry-standard packaging for automated assembly:

• Carrier Tape: 12mm wide tape.
• Reel Size: 7-inch (178mm) diameter.
• Quantity per Reel: 1000 pieces (full reel).
• Minimum Order Quantity (MOQ): 500 pieces for remainder quantities.
• Pocket Coverage: Empty component pockets are sealed with a top cover tape.
• Missing Lamps: A maximum of two consecutive missing LEDs (empty pockets) is allowed per the packaging specification (ANSI/EIA 481).

8. Application Suggestions

8.1 Typical Application Scenarios

• Automotive Interior Accessories: Primary application. Ideal for dashboard indicator lights, switch illumination, gear shift position indicators, audio system button backlighting, and general interior status indicators.
• Consumer Electronics: Power status indicators, button backlights, or decorative lighting in appliances, audio/video equipment, and computer peripherals.
• General Indicator Applications: Any application requiring a compact, reliable, bright red indicator with a wide viewing angle.

8.2 Design Considerations & Notes

• Current Driving: Always drive LEDs with a constant current source or a current-limiting resistor. The forward voltage has a tolerance and negative temperature coefficient, so a voltage source alone will lead to unstable and potentially destructive current levels.
• Thermal Design: To maintain performance and longevity, implement proper thermal management. Use the recommended PCB pad layout, connect the anode thermal pad to a large copper area or internal plane, and consider the operating ambient temperature when estimating light output.
• ESD Protection: While not explicitly stated as sensitive in this datasheet, standard ESD handling precautions for semiconductor devices are recommended during assembly.
• Reverse Voltage Protection: The LED is not designed for reverse bias. Ensure circuit design prevents reverse voltage application (e.g., in AC or bipolar signal applications, use a series blocking diode).
• Application Scope: The datasheet cautions that these LEDs are intended for ordinary electronic equipment. For applications requiring exceptional reliability where failure could jeopardize life or health (aviation, medical, critical safety systems), consultation with the component manufacturer is required prior to design-in.

9. Technical Comparison & Differentiation

While a direct competitor comparison is not provided in the source document, the LTSA-G6SPVEKTU's key differentiating features can be inferred from its specifications:

• Material Technology (AlInGaP): Compared to older technologies like GaAsP, AlInGaP offers higher efficiency, better temperature stability, and more saturated color purity for red and amber LEDs.
• Wide Viewing Angle (120°): This is a significantly wider beam than many standard SMD LEDs (which may be 60-90°), making it superior for applications requiring broad visibility without secondary optics.
• AEC-Q101 Reference: The mention of qualification per AEC-Q101, even if for accessory applications, indicates a design and testing focus on automotive-grade reliability, which typically surpasses commercial-grade components in terms of temperature cycling, humidity resistance, and longevity testing.
• Thermal Performance: The specified thermal resistance parameters (R_θJS=30°C/W) and the explicit use of the anode as a heat sink suggest a package designed for better thermal performance than basic LED packages, allowing for higher continuous operating currents.

10. Frequently Asked Questions (Based on Technical Parameters)

Q1: What is the difference between Peak Wavelength (631nm) and Dominant Wavelength (620-629nm)?
A: Peak Wavelength is the physical peak of the light spectrum the chip emits. Dominant Wavelength is the single wavelength the human eye perceives the color to be, calculated from chromaticity coordinates. They are related but different metrics; Dominant Wavelength is used for color binning.

Q2: Can I drive this LED with 200mA continuously?
A: While 200mA is the absolute maximum DC current, continuous operation at this limit will generate significant heat (up to ~530mW). For reliable long-term operation, it is advisable to derate the current. Operating at the typical test condition of 140mA or lower will improve efficiency and lifespan.

Q3: Why is the minimum current 5mA?
A: Below this threshold, the light output from the LED becomes very low and potentially unstable. The semiconductor junction requires a minimum current to overcome non-radiative recombination processes and produce useful, consistent illumination.

Q4: How do I select the correct V_f bin for my design?
A: If driving multiple LEDs in parallel from the same voltage source, using LEDs from the same V_f bin ensures more uniform current sharing and brightness. For designs using individual current-limiting resistors or constant-current drivers per LED, the V_f bin is less critical.

Q5: The MSL is Level 2. What happens if I don't bake old components?
A: Absorbed moisture can rapidly vaporize during the high-temperature reflow soldering process, creating steam pressure inside the LED package. This can cause internal delamination, cracking of the epoxy lens (popcorning), or bond wire lift-off, leading immediate or latent failure.

11. Practical Design & Usage Case

Scenario: Designing a dashboard cluster with multiple red warning indicators.

A designer is creating a new instrument cluster for a vehicle. Several warning lights (e.g., brake system, battery) need to be bright red and clearly visible from the driver's position. The LTSA-G6SPVEKTU is selected for its automotive reference, wide 120° viewing angle (ensuring visibility even from off-axis glances), and AlInGaP red color.

Implementation: The designer uses a constant-current LED driver IC capable of supplying 140mA per channel. Each LED is connected to its own driver channel. The PCB layout strictly follows the recommended pad pattern, and the anode thermal pad for each LED is connected to a dedicated copper pour on the top layer, which is stitched with multiple vias to an internal ground plane for heat spreading. The LEDs are specified from the EA luminous intensity bin (7.1-9.0 cd) and the E voltage bin (2.20-2.35V) for consistency. The assembled PCBs undergo IR reflow using the specified lead-free profile. After assembly, the indicators provide uniform, bright red illumination across the dashboard, meeting all visibility and reliability requirements for the automotive environment.

12. Principle of Operation Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that convert electrical energy directly into light through a process called electroluminescence. The core of the LTSA-G6SPVEKTU is a chip made from Aluminum Indium Gallium Phosphide (AlInGaP). This material is a compound semiconductor with a specific bandgap energy.

When a forward voltage is applied across the LED's p-n junction, electrons from the n-type region and holes from the p-type region are injected into the active region. When an electron recombines with a hole, it falls from a higher energy state in the conduction band to a lower energy state in the valence band. The energy difference is released in the form of a photon (a particle of light). The wavelength (color) of this photon is determined by the bandgap energy of the semiconductor material. For AlInGaP, this bandgap is engineered to produce photons in the red portion of the visible spectrum (~620-630nm). The clear epoxy lens surrounding the chip protects it, shapes the light output beam (to 120 degrees), and enhances light extraction from the semiconductor material.

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