ALFS1G-C0 LED Datasheet - SMD Ceramic Package - 400lm @1000mA - 3.3V - 120° Viewing Angle - Automotive Grade

1. Product Overview

The ALFS1G-C0 series represents a high-performance, surface-mount LED component engineered for demanding automotive lighting applications. This device is housed in a robust ceramic package, offering superior thermal management and reliability essential for the harsh operating environments found in vehicles. Its primary design focus is on providing a high luminous output with consistent performance across a wide temperature range, making it a suitable choice for safety-critical exterior lighting functions.

The core advantages of this LED include its high typical luminous flux of 400 lumens at a drive current of 1000mA, a wide 120-degree viewing angle for excellent light distribution, and compliance with stringent automotive industry standards. It is specifically targeted at the automotive exterior lighting market, including applications where durability, longevity, and performance stability are non-negotiable.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The key operational parameters define the LED's performance envelope. The forward current (I_F) has a typical operating point of 1000mA, with a minimum of 50mA and an absolute maximum rating of 1500mA. Operating below 50mA is not recommended. The luminous flux (Φ_v) is specified as 360 lm (Min), 400 lm (Typ), and 500 lm (Max) when driven at 1000mA, measured at a thermal pad temperature of 25°C with a measurement tolerance of ±8%.

The forward voltage (V_F) ranges from 2.90V to 3.80V, with a typical value of 3.30V at 1000mA (±0.05V tolerance). This parameter is crucial for driver design and power dissipation calculations. The correlated color temperature (CCT) for the cool white variant spans from 5180K to 6893K under typical conditions.

2.2 Thermal and Absolute Maximum Ratings

Thermal management is critical for LED longevity. The thermal resistance from the junction to the solder point (R_thJS) is specified with two values: 4.0 K/W (Typ) / 4.4 K/W (Max) for the real condition and 3.0 K/W (Typ) / 3.4 K/W (Max) for the electrical measurement condition. The maximum allowable junction temperature (T_J) is 150°C.

The Absolute Maximum Ratings define the limits beyond which permanent damage may occur. These include a maximum power dissipation (P_d) of 5700 mW, an operating temperature range (T_opr) of -40°C to +125°C, and a storage temperature range (T_stg) of -40°C to +125°C. The device can withstand an ESD (HBM) of up to 8 kV and a reflow soldering temperature of 260°C.

3. Binning System Explanation

To ensure color and brightness consistency in production, the LEDs are sorted into bins based on key parameters.

3.1 Luminous Flux Binning

For the Cool White version, luminous flux bins are defined from Group C4 to C9. Each bin covers a specific flux range, for example, bin C5 covers 380-400 lm, and bin C6 covers 400-425 lm, all measured at the typical forward current with a 25ms pulse. This allows designers to select LEDs with the required brightness output for their application.

3.2 Forward Voltage Binning

Forward voltage is binned into three groups: 1A (2.90V - 3.20V), 1B (3.20V - 3.50V), and 1C (3.50V - 3.80V). Binning by voltage helps in designing more consistent driver circuits and managing thermal loads across multiple LEDs in an array.

3.3 Color Coordinate Binning (Cool White)

The color characteristics are defined using the CIE 1931 chromaticity coordinates (x, y). The datasheet provides a detailed bin structure chart and table for cool white LEDs. Bins are designated with codes like 64A, 64B, 60A, etc., each representing a specific quadrilateral area on the CIE chart. For instance, bin 64A covers coordinates within the boundaries defined by (0.3109, 0.3382), (0.3161, 0.3432), (0.3169, 0.3353), and (0.3120, 0.3306), corresponding to a correlated color temperature reference range. This precise binning ensures tight color consistency, which is vital for automotive lighting where color matching between multiple light sources is important.

4. Performance Curve Analysis

The provided graphs offer deep insight into the LED's behavior under various conditions.

4.1 Forward Current vs. Forward Voltage (IV Curve)

The graph shows a non-linear relationship, typical for LEDs. The forward voltage increases with current, starting around 2.7V at very low currents and reaching approximately 3.5V at the maximum rated current of 1500mA. This curve is essential for selecting the appropriate current-limiting driver topology.

4.2 Relative Luminous Flux vs. Forward Current

Luminous output increases sub-linearly with current. While output rises significantly from 50mA to 1000mA, the relative increase diminishes as current approaches the maximum rating, indicating reduced efficacy at higher currents due to increased thermal load.

4.3 Thermal Performance Graphs

The Relative Luminous Flux vs. Junction Temperature graph demonstrates thermal quenching. As the junction temperature rises from -40°C to 150°C, the relative luminous flux decreases. At 100°C, the output is roughly 85-90% of its value at 25°C, highlighting the critical need for effective heat sinking in high-power applications.

The Relative Forward Voltage vs. Junction Temperature graph shows that V_F decreases linearly with increasing temperature (a negative temperature coefficient), which is a characteristic of semiconductor bandgap changes. This property can sometimes be used for indirect temperature monitoring.

The Chromaticity Shift graphs show that both the forward current and junction temperature cause small but measurable shifts in the CIE x and y coordinates. These shifts must be considered in color-critical applications.

4.4 Forward Current Derating and Pulse Handling

The Forward Current Derating Curve is vital for reliability design. It dictates the maximum allowable continuous forward current as a function of the solder pad temperature (T_S). For example, at a T_S of 110°C, the maximum I_F is 1500mA. At the maximum allowable T_S of 125°C, the maximum I_F is derated to 1200mA. Operating within this curve is mandatory to prevent overheating and premature failure.

The Pulse Handling Capability graph shows the LED can withstand currents significantly higher than the DC maximum rating for very short pulse durations (e.g., microseconds to milliseconds) at various duty cycles. This is relevant for pulsed operation schemes sometimes used in sensing or communication.

5. Mechanical, Packaging & Assembly Information

5.1 Mechanical Dimensions and Pad Design

The LED utilizes a surface-mount ceramic package. While the exact dimensions are not provided in the excerpt, the datasheet includes dedicated sections for Mechanical Dimension drawings and Recommended Soldering Pad layout. Adhering to the recommended pad geometry is crucial for achieving reliable solder joints, proper thermal transfer to the PCB, and ensuring mechanical stability.

5.2 Reflow Soldering Profile and Precautions

A specific Reflow Soldering Profile is provided, with a peak temperature rating of 260°C. Following this profile is essential to avoid thermal damage to the LED package or the internal die attach materials. The Precaution for Use section likely contains important handling, storage, and assembly guidelines to prevent ESD damage, moisture absorption (MSL 2), and mechanical stress.

5.3 Packaging Information

The Packaging Information section details how the LEDs are supplied (e.g., tape and reel specifications), which is necessary for automated assembly processes.

6. Application Guidelines and Design Considerations

6.1 Target Applications

The primary applications listed are all automotive exterior lighting: Headlamps (main beam, low beam), Daytime Running Lights (DRL), and Fog Lamps. These applications demand high reliability, wide operating temperature tolerance, and robust performance against environmental factors like vibration and humidity.

6.2 Critical Design Considerations

• Thermal Design: The low R_thJS of the ceramic package is beneficial, but a high-performance thermal path from the solder pads to the system heatsink (e.g., metal-core PCB or active cooling) is mandatory to keep the junction temperature low, especially when driving at high currents. Use the derating curve as a design limit.
• Drive Circuitry: A constant-current driver is required to ensure stable light output and prevent thermal runaway. The driver must be designed to accommodate the forward voltage bin range and provide the necessary current up to 1500mA.
• Optical Design: The 120° viewing angle is suitable for creating broad, even illumination patterns. Secondary optics (lenses, reflectors) will be needed to shape the beam for specific applications like headlamp cutoffs or DRL signatures.
• Environmental Robustness: The product notes compliance with sulfur robustness (Class A1), Halogen Free, and RoHS/REACH standards, which are essential for automotive and other regulated industries. Designers should ensure the entire assembly (PCB, solder, conformal coating) meets complementary standards.

7. Technical Comparison and Differentiation

While a direct comparison to other products is not in the datasheet, key differentiators of this LED can be inferred. The combination of a ceramic package (superior thermal performance and reliability over plastic packages), AEC-Q102 qualification (automotive-grade reliability testing), high luminous flux at a standard 1000mA drive current, and detailed binning for both flux and color places this component in the high-reliability segment for automotive lighting. Its 8kV ESD rating and sulfur resistance further enhance its suitability for harsh environments.

8. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED at 1500mA continuously?
A: Only if you can guarantee the solder pad temperature (T_S) is at or below 110°C, as per the derating curve. At higher pad temperatures, the current must be reduced. For reliable long-term operation, designing for a typical current of 1000mA or lower is advisable.

Q: What is the meaning of MSL 2?
A: Moisture Sensitivity Level 2. This means the packaged LED can be stored in a dry environment (<60% RH) for up to one year. Before reflow soldering, if the package has been exposed to ambient conditions beyond its floor life, it must be baked to remove moisture to prevent "popcorning" damage during reflow.

Q: How do I interpret the color bins like 64A or 60B?
A: These are codes for specific regions on the CIE chromaticity diagram. You must cross-reference the bin code with the provided table and chart to find the exact quadrilateral of CIE x,y coordinates that the LED's color will fall within. This ensures color consistency when using multiple LEDs.

Q: Why is there a minimum current of 50mA?
A: Operating at extremely low currents may lead to unstable or non-uniform light emission. The specified minimum ensures the LED operates in a stable region of its performance characteristics.

9. Operational Principles and Trends

9.1 Basic Operating Principle

This is a solid-state light-emitting diode. When a forward voltage exceeding its bandgap voltage is applied, electrons and holes recombine in the active semiconductor region, releasing energy in the form of photons (light). The specific materials and structure of the semiconductor layers determine the wavelength (color) of the emitted light. The ceramic package serves primarily as a robust mechanical housing and, critically, as an efficient thermal conduit to transfer heat generated at the semiconductor junction (due to non-radiative recombination and electrical resistance) away to the PCB and heatsink.

9.2 Industry Trends

The development of LEDs like the ALFS1G-C0 reflects key trends in automotive lighting: the shift from traditional halogen and HID sources to all-solid-state LED lighting for higher efficiency, longer life, and design flexibility. There is a continuous push for higher luminous efficacy (more lumens per watt), improved thermal management packages (like advanced ceramics), tighter color and flux binning for better uniformity, and enhanced reliability standards (AEC-Q102, sulfur resistance) to meet the 10-15 year lifespan expectations of automotive systems. Furthermore, integration of multiple functions (e.g., adaptive driving beam) into compact LED modules is a growing trend.