SMD LED LTSA-G6SPVAKTU Datasheet - Amber AlInGaP - 140mA - 2.65V - 530mW - English Technical Document

1. Product Overview

This document provides the complete technical specifications for a surface-mount device (SMD) LED designed for high-reliability applications. The component utilizes an Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material to produce amber light emission, encapsulated in a water-clear lens package. It is engineered to meet the stringent requirements of modern electronic assembly processes and demanding operational environments.

1.1 Core Advantages and Target Market

The primary design advantages of this LED include its compatibility with automated pick-and-place equipment and standard infrared (IR) reflow soldering processes, which are critical for high-volume manufacturing. The package conforms to EIA standard dimensions, ensuring interchangeability and ease of integration into existing PCB layouts. Its key qualification against the AEC-Q101 standard, Revision D, highlights its suitability for automotive electronics, specifically targeting non-critical accessory applications within vehicles. The component is also compliant with the Restriction of Hazardous Substances (RoHS) directive.

2. In-Depth Technical Parameter Analysis

The performance of the LED is defined under specific electrical, optical, and thermal conditions, typically measured at an ambient temperature (Ta) of 25°C.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed. Key limits include a maximum power dissipation of 530mW, a peak forward current of 400mA (under pulsed conditions with a 1/10 duty cycle and 0.1ms pulse width), and a continuous DC forward current range from 5mA to 200mA. The device is rated for an operating and storage temperature range of -40°C to +110°C. It can withstand Electrostatic Discharge (ESD) up to 2kV per the Human Body Model (HBM, Class 2 per ANSI/ESDA/JEDEC JS-001). The package can endure infrared reflow soldering at a peak temperature of 260°C for up to 10 seconds, which is standard for lead-free (Pb-free) assembly processes.

2.2 Thermal Characteristics

Thermal management is crucial for LED performance and longevity. The thermal resistance from the semiconductor junction to the ambient air (RθJA) is typically 50°C/W when mounted on a standard FR4 PCB with a 1.6mm thickness and a 16mm² copper pad. The thermal resistance from the junction to the solder point (RθJS) is typically 30°C/W, providing a more direct path for heat dissipation into the circuit board. The maximum allowable junction temperature (Tj) is 125°C. Exceeding this temperature will accelerate light output degradation and can lead to catastrophic failure.

2.3 Electrical and Optical Characteristics

These are the typical performance parameters measured under standard test conditions (IF = 140mA, Ta=25°C). The luminous intensity (Iv) ranges from a minimum of 7.1 candela (cd) to a maximum of 11.2 cd. The spatial distribution of light is characterized by a wide viewing angle (2θ½) of 120 degrees, meaning the luminous intensity is half of its peak value at ±60 degrees from the central axis. The light emission peaks at a wavelength (λP) of approximately 625 nanometers (nm). The dominant wavelength (λd), which defines the perceived color, is specified between 612 nm and 624 nm. The spectral bandwidth (Δλ), indicating color purity, is typically 18 nm. The forward voltage (VF) required to drive the LED at 140mA ranges from 1.90V to 2.65V. The reverse leakage current (IR) is typically 10 μA when a reverse bias of 12V is applied, though the device is not designed for operation in reverse bias.

3. Bin Ranking System Explanation

To ensure consistency in application, LEDs are sorted into performance bins based on key parameters post-manufacturing. The bin code, printed on the product label, follows the format: Vf Rank / Iv Rank / Wd Rank (e.g., F/EA/3).

3.1 Forward Voltage (Vf) Binning

LEDs are categorized into five voltage bins (C through G) based on their forward voltage drop at 140mA. Bin C covers 1.90V to 2.05V, Bin D: 2.05V to 2.20V, Bin E: 2.20V to 2.35V, Bin F: 2.35V to 2.50V, and Bin G: 2.50V to 2.65V. Each bin has a tolerance of ±0.1V. This allows designers to select LEDs with consistent voltage requirements for current regulation circuits.

3.2 Luminous Intensity (Iv) Binning

The light output is sorted into two intensity bins. Bin EA has an intensity range of 7.1 cd to 9.0 cd (equivalent to 20.0 to 25.2 lumens), while Bin EB ranges from 9.0 cd to 11.2 cd (25.2 to 31.3 lumens). The tolerance for each intensity bin is ±11%. This binning ensures uniform brightness in applications requiring multiple LEDs.

3.3 Dominant Wavelength (Wd) Binning

The color (dominant wavelength) is sorted into three bins to maintain color consistency. Bin 2: 612 nm to 616 nm, Bin 3: 616 nm to 620 nm, and Bin 4: 620 nm to 624 nm. The tolerance for each wavelength bin is ±1 nm. This is critical for applications where precise color matching is required, such as in indicator clusters or backlighting.

4. Performance Curve Analysis

Graphical data provides deeper insight into the device's behavior under varying conditions.

4.1 Relative Luminous Intensity vs. Forward Current

A characteristic curve shows the relationship between forward current (IF) and relative luminous intensity. The light output increases with current but in a non-linear fashion. Operating significantly above the recommended current (e.g., 200mA) may yield diminishing returns in light output while drastically increasing heat generation and accelerating degradation. The curve underscores the importance of proper current driving, typically via a constant-current source or a current-limiting resistor.

4.2 Forward Voltage vs. Forward Current

This IV curve illustrates the diode's exponential relationship between voltage and current. The \"knee\" voltage, where current begins to increase rapidly, is characteristic of the AlInGaP material system. The curve is essential for designing the driving circuitry, ensuring sufficient voltage headroom from the power supply to achieve the desired operating current across the specified VF range and over temperature variations.

4.3 Spatial Distribution (Radiation Pattern)

A polar diagram depicts the spatial radiation pattern, confirming the 120-degree viewing angle. The pattern is typically Lambertian or near-Lambertian, meaning the intensity is proportional to the cosine of the viewing angle. This wide, even distribution is ideal for applications requiring broad-area illumination or wide-angle visibility, such as status indicators.

5. Mechanical and Packaging Information

5.1 Package Dimensions and Polarity

The LED conforms to a standard SMD footprint. Detailed mechanical drawings specify the length, width, height, lead spacing, and overall tolerances (typically ±0.2mm). It is critical to note that the anode lead frame also serves as the primary heat sink for the device. Proper PCB pad design must connect to this anode pad to facilitate effective heat dissipation. The cathode is typically identified by a visual marker, such as a notch or a green marking on the package.

5.2 Recommended PCB Attachment Pad Layout

A diagram shows the optimal copper pad design on the printed circuit board for infrared reflow soldering. This layout ensures reliable solder joint formation, proper thermal transfer from the LED's heat sink (anode) to the PCB, and minimizes the risk of tombstoning (one end lifting during reflow). The pad size and shape are designed to match the lead frames for maximum solderability and mechanical strength.

6. Soldering, Assembly, and Handling Guide

6.1 IR Reflow Soldering Profile

A detailed temperature-time graph specifies the recommended reflow profile for lead-free solder pastes, per J-STD-020. Key parameters include the preheat temperature ramp rate, soak time and temperature, time above liquidus (TAL), peak temperature (not exceeding 260°C), and cooling rate. Adhering to this profile is essential to prevent thermal shock, delamination, or solder joint defects while ensuring the moisture-sensitive device (MSL Level 2) is properly processed.

6.2 Storage and Moisture Sensitivity

The LED is classified as Moisture Sensitivity Level (MSL) 2 per JEDEC J-STD-020. In its sealed moisture-barrier bag with desiccant, it has a shelf life of one year when stored at ≤30°C and ≤70% RH. Once the bag is opened, the components must be used within a specified floor life (typically 168 hours for MSL2 at ≤30°C/60% RH) or be rebaked (e.g., 60°C for 48 hours) before reflow to prevent \"popcorning\" damage from absorbed moisture vaporizing during soldering.

6.3 Cleaning

If post-solder cleaning is necessary, only specified solvents should be used. Immersing the LED in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute is acceptable. Harsh or unspecified chemicals can damage the epoxy lens or the package markings.

7. Packaging and Ordering Specifications

7.1 Tape and Reel Packaging

For automated assembly, the LEDs are supplied embossed carrier tape, sealed with a cover tape. The tape dimensions, pocket size, and feed direction are specified per EIA-481 standards. The components are wound onto standard 7-inch (178mm) diameter reels. A full reel contains 1000 pieces. Partial reels (remainders) have a minimum order quantity of 500 pieces. The packaging specification also defines the maximum allowable number of consecutive empty pockets (two).

7.2 Reel Dimensions

Mechanical drawings detail the reel's hub diameter, flange diameter, overall width, and keying features to ensure compatibility with standard SMT feeder equipment.

8. Application Guidelines and Design Considerations

8.1 Target Application Scenarios

The primary application domain is automotive electronics, specifically for accessory functions. This includes interior lighting, dashboard backlighting for non-critical indicators, center console illumination, and other non-safety-critical signaling applications within the vehicle. Its AEC-Q101 qualification provides assurance for the temperature, humidity, and operational stress typical in automotive environments.

8.2 Design Considerations

• Current Driving: Always use a constant current driver or a series current-limiting resistor. Calculate the resistor value based on the power supply voltage (Vcc), the LED's maximum forward voltage (VF max from the bin), and the desired operating current (IF). Use the formula: R = (Vcc - VF) / IF. Ensure the resistor's power rating is sufficient (P = (Vcc - VF) * IF).
• Thermal Management: The anode is the thermal pad. Design the PCB with an adequate copper pour connected to this pad to act as a heat sink. For high-current or high-ambient-temperature operation, thermal vias to inner or bottom layers can significantly improve heat dissipation and maintain a lower junction temperature.
• ESD Protection: Although rated for 2kV HBM, implementing ESD protection diodes on sensitive input lines or using conductive handling practices in the assembly area is recommended for enhanced reliability.
• Optical Design: The 120-degree viewing angle provides wide coverage. For focused light, external secondary optics (lenses) may be required. The water-clear lens is suitable for applications where the true amber chip color is desired.

9. Technical Comparison and Differentiation

Compared to standard through-hole LEDs, this SMD component offers significant advantages: much smaller footprint, lower profile for slim designs, superior suitability for automated assembly, and better thermal performance via the PCB. Within the SMD amber LED segment, its key differentiators are its explicit AEC-Q101 qualification for automotive use, the wide 120-degree viewing angle, and the detailed binning system for color and intensity consistency. The use of AlInGaP technology typically offers higher efficiency and better temperature stability compared to older technologies like GaAsP for amber colors.

10. Frequently Asked Questions (FAQ)

10.1 What is the difference between peak wavelength and dominant wavelength?

Peak wavelength (λP) is the single wavelength at which the spectral power distribution is maximum. Dominant wavelength (λd) is derived from the CIE chromaticity diagram and represents the single wavelength of a pure monochromatic light that would match the perceived color of the LED. λd is more relevant for color specification in applications.

10.2 Can I drive this LED with a 3.3V supply without a resistor?

No. The forward voltage ranges up to 2.65V. Connecting it directly to a 3.3V source would force a current limited only by the diode's dynamic resistance and the source's internal resistance, likely exceeding the absolute maximum current rating and destroying the LED instantly. A current-limiting resistor or regulator is always required.

10.3 Is this LED suitable for safety-critical applications like brake lights or turn signals?

The datasheet explicitly states it is intended for \"accessory applications\" and advises consulting the manufacturer for applications where failure could jeopardize safety. For safety-critical functions like exterior signaling, components with more rigorous qualification (e.g., AEC-Q102 for discrete LEDs) and potentially different reliability grades should be selected.

10.4 How do I interpret the bin code F/EA/3 on the label?

This indicates a specific performance subset: F = Forward Voltage between 2.35V and 2.50V. EA = Luminous Intensity between 7.1 cd and 9.0 cd. 3 = Dominant Wavelength between 616 nm and 620 nm. This allows precise matching of LEDs within a single production batch or project.

11. Practical Design and Usage Example

Scenario: Designing a status indicator for an automotive infotainment control knob. The indicator must be visible from a wide angle, operate from the vehicle's 12V system (regulated to 5V locally), and maintain consistent color and brightness.

Implementation:

1. Selection: Choose an LED from Bin F/EB/3 for higher brightness (EB) and consistent orange-amber color (Bin 3). The voltage bin (F) is noted for driver design.
2. Schematic: Use a 5V rail. Calculate the series resistor: R = (5V - 2.5V_max) / 0.14A ≈ 17.9Ω. Select a standard 18Ω resistor with a power rating of at least (5V-2.5V)*0.14A = 0.35W; a 0.5W resistor is recommended.
3. PCB Layout: Design the footprint per the recommended pad layout. Connect the anode pad to a large copper pour on the top layer, stitched with multiple thermal vias to an internal ground plane for heat sinking. Place the current-limiting resistor close to the LED.
4. Assembly: Follow the specified IR reflow profile. Ensure the reel is used within its floor life after opening the moisture barrier bag.
5. Result: A reliable, consistently bright, wide-angle amber indicator suitable for the automotive cabin environment.

12. Technology Principle Introduction

This LED is based on Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material grown on a substrate. When a forward voltage is applied, electrons and holes are injected into the active region where they recombine, releasing energy in the form of photons. The specific ratio of aluminum, indium, and gallium in the crystal lattice determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, amber (~615nm). The water-clear epoxy encapsulation protects the semiconductor die, acts as a lens to shape the light output, and may contain phosphors or dyes (though for a pure amber AlInGaP LED, it is typically clear). The anode and cathode leads provide electrical connection and mechanical attachment, with the anode frame designed to efficiently conduct heat away from the active junction.

13. Industry Trends and Development

The general trend in SMD LEDs for automotive and industrial applications is towards higher efficiency (more lumens per watt), increased power density, improved reliability under harsher temperature and humidity conditions, and enhanced color consistency through tighter binning. There is also a drive towards miniaturization while maintaining or improving thermal performance. The adoption of advanced materials and packaging techniques, such as flip-chip designs and ceramic substrates, continues to push these boundaries. Furthermore, integration with drivers and control circuitry into \"smart LED\" modules is an emerging trend for complex lighting systems. The component described here represents a mature, reliable solution within the broader ecosystem of surface-mount optoelectronics, balancing performance, cost, and manufacturability for its target applications.