ALFS3BD-C010001L1-AM LED Datasheet - SMD Ceramic Package - 960lm @ 1000mA - 5850K Cool White - 120° Viewing Angle - English Technical Document

1. Product Overview

The ALFS3BD-C010001L1-AM is a high-performance, surface-mount LED designed specifically for demanding automotive lighting applications. It utilizes a ceramic package for superior thermal management and reliability. The device is engineered to meet the stringent requirements of the automotive industry, including AEC-Q102 qualification, making it suitable for use in harsh environmental conditions. Its primary applications include exterior lighting systems such as headlamps, daytime running lights (DRL), and fog lamps.

1.1 Core Advantages

• High Luminous Output: Delivers a typical luminous flux of 960 lumens at a drive current of 1000mA, enabling bright and efficient lighting solutions.
• Robust Thermal Performance: The ceramic substrate offers excellent heat dissipation, with a typical thermal resistance (junction to solder) of 2.3 K/W, contributing to long-term stability and lumen maintenance.
• Automotive-Grade Reliability: Qualified according to AEC-Q102 standards, ensuring performance under automotive temperature ranges (-40°C to +125°C) and vibration.
• Environmental Compliance: The product is compliant with RoHS, REACH, and halogen-free requirements (Br<900ppm, Cl<900ppm, Br+Cl<1500ppm).
• Wide Viewing Angle: A 120-degree viewing angle provides a broad and uniform light distribution.

2. Technical Parameter Deep-Dive

This section provides a detailed, objective analysis of the key electrical, optical, and thermal parameters specified in the datasheet.

2.1 Photometric and Electrical Characteristics

The LED's performance is characterized under specific test conditions, typically at a solder pad temperature (Ts) of 25°C and a forward current (IF) of 1000mA.

• Luminous Flux (Φv): The typical value is 960 lm, with a minimum of 800 lm and a maximum of 1100 lm. The measurement tolerance is ±8%. It is crucial to note that this flux is measured at Ts=25°C; real-world flux will be lower at higher operating temperatures.
• Forward Voltage (VF): Ranges from a minimum of 8.7V to a maximum of 11.25V, with a typical value of 10V at 1000mA. The forward voltage binning structure (Groups 3A, 3B, 3C) helps designers select LEDs with consistent electrical characteristics for multi-LED arrays.
• Forward Current (IF): The absolute maximum rating is 1500 mA. The recommended operating current is up to 1000 mA, but this must be derated based on the solder pad temperature, as shown in the derating curve.
• Color Temperature (K): The typical correlated color temperature (CCT) is 5850K, classified as cool white. The binning structure shows a range from approximately 5180K to 6680K, allowing for selection based on application-specific color requirements.
• Viewing Angle (ψ): Defined as 120 degrees, which is the full angle at which the luminous intensity is half of the peak value (ψ = 2φ, where φ is the half-angle).

2.2 Absolute Maximum Ratings and Thermal Characteristics

Operating beyond these limits may cause permanent damage to the device.

• Junction Temperature (Tj): The maximum allowable junction temperature is 150°C. Maintaining Tj well below this limit is critical for reliability and lifetime.
• Power Dissipation (Pd): Rated at 16900 mW. This is a theoretical maximum based on thermal limits; actual usable power is determined by the derating curve.
• Thermal Resistance (RthJS): Two values are provided: RthJS_real (typical 2.3 K/W) and RthJS_el (typical 1.6 K/W). The "real" value is measured under actual operating conditions (1000mA), while the "el" value is measured with a low sensing current. For thermal design, the RthJS_real value should be used for accurate junction temperature estimation.
• ESD Sensitivity: The device can withstand Electrostatic Discharge up to 8KV (Human Body Model, R=1.5kΩ, C=100pF), indicating good inherent protection but still requiring careful handling procedures.

3. Binning System Explanation

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

3.1 Luminous Flux Binning

For the Cool White group, luminous flux is binned into five categories (E1 to E5), each covering a 60 lm range (e.g., E3: 920-980 lm). The typical product (960 lm) falls into bin E3 or E4. The datasheet highlights the specific bins that are available for this part number.

3.2 Forward Voltage Binning

Forward voltage is grouped into three bins: 3A (8.7V - 9.55V), 3B (9.55V - 10.40V), and 3C (10.40V - 11.25V). Selecting LEDs from the same voltage bin is important for current balancing in parallel configurations.

3.3 Color Binning (Chromaticity)

The color bin structure is defined on the CIE 1931 chromaticity diagram. The provided chart shows the ECE (Economic Commission for Europe) bin structure for white LEDs, with the target 5850K point located within a specific quadrilateral region (e.g., likely within bins 56 or 60 series). The exact bin code for this part is defined by its CIE x and y coordinates relative to this structure.

4. Performance Curve Analysis

The graphs in the datasheet provide critical insights into the LED's behavior under varying conditions.

4.1 IV Curve and Relative Luminous Flux

The Forward Current vs. Forward Voltage curve shows a non-linear relationship. The voltage increases with current, and designers must account for this when designing the driver circuit. The Relative Luminous Flux vs. Forward Current curve is sub-linear; increasing current yields diminishing returns in light output while generating significantly more heat. Operating at 1000mA appears to be a good compromise between output and efficiency.

4.2 Temperature Dependence

The Relative Luminous Flux vs. Junction Temperature graph is crucial. Luminous flux decreases as junction temperature rises. At 100°C, the relative flux is only about 85% of its value at 25°C. This underscores the importance of an effective thermal management system in the final application. The Relative Forward Voltage vs. Junction Temperature curve shows a negative temperature coefficient, with VF decreasing linearly as temperature increases. This property can sometimes be used for temperature sensing.

4.3 Spectral Distribution and Chromaticity Shift

The Relative Spectral Distribution plot shows a peak in the blue wavelength region (around 450nm) with a broad phosphor-converted yellow emission, typical for a white LED using a blue chip. The Chromaticity Coordinates vs. Forward Current and vs. Junction Temperature graphs show minimal shift (Δx, Δy < 0.02), indicating good color stability over operating conditions, which is vital for automotive lighting where color consistency is mandated.

4.4 Forward Current Derating Curve

This is arguably the most important graph for system design. It defines the maximum allowable forward current as a function of the solder pad temperature (Ts). For example:

• At Ts = 25°C, IF can be 1500 mA (absolute max).
• At Ts = 103°C, IF must be reduced to 1500 mA (the curve's first point).
• At Ts = 125°C (max operating temperature), IF must be derated to approximately 823 mA.

This curve directly links the thermal design of the PCB and heatsink to the usable drive current and light output.

5. Mechanical and Packaging Information

The LED uses a Surface-Mount Device (SMD) ceramic package. The specific mechanical dimensions, including length, width, height, and pad locations, are detailed in the "Mechanical Dimension" drawing (not fully extracted here but referenced). The package is designed for compatibility with automated pick-and-place and reflow soldering processes. The "Recommended Soldering Pad" layout is provided to ensure proper solder joint formation and optimal thermal transfer from the LED's thermal pad to the PCB.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The datasheet specifies a reflow soldering profile with a peak temperature of 260°C. This is a standard lead-free (Pb-free) reflow requirement. The profile will include preheat, soak, reflow, and cooling zones with specific time and temperature constraints to prevent thermal shock and ensure reliable solder joints without damaging the LED package or internal materials (which have a Moisture Sensitivity Level, MSL, of 2).

6.2 Precautions for Use

• ESD Protection: Although rated for 8KV HBM, standard ESD precautions should be followed during handling and assembly.
• Current Control: The LED must be driven by a constant current source, not a constant voltage source, to prevent thermal runaway.
• Thermal Management: A properly designed thermal path from the LED's solder pads to the system heatsink is mandatory to maintain junction temperature within safe limits and achieve rated performance and lifetime.
• Sulfur Robustness: The datasheet mentions sulfur robustness, indicating some resistance to sulfur-containing environments, but additional conformal coating may be necessary in highly corrosive atmospheres.

7. Application Suggestions

7.1 Typical Application Scenarios

• Headlamp (Low/High Beam): Requires precise optical control. The high flux and small source size of this LED make it suitable for projector or reflector-based headlamp systems.
• Daytime Running Light (DRL): Requires high efficiency and reliability. The LED's output and wide viewing angle are advantageous for creating distinctive DRL signatures.
• Fog Lamp: Requires a wide, flat beam pattern. The 120° viewing angle provides a good starting point for optics designed to cut under fog.

7.2 Design Considerations

• Optical Design: Secondary optics (lenses, reflectors) are almost always required to shape the raw LED emission into a regulated beam pattern compliant with automotive lighting standards (SAE, ECE).
• Electrical Design: Use a constant-current LED driver capable of supplying up to 1000mA (or the derated current based on thermal analysis) and with a compliance voltage higher than the maximum VF of the LED string. Consider dimming functionality (PWM) for DRL/position light applications.
• Thermal Design: This is paramount. Use a metal-core PCB (MCPCB) or a standard FR4 PCB with thermal vias under the LED's thermal pad connected to a large copper plane or an external heatsink. Perform thermal simulations to predict the solder pad temperature (Ts) under worst-case ambient conditions.
• Bin Selection: For applications requiring uniform appearance (e.g., multiple LEDs in a DRL strip), specify tight bins for luminous flux and chromaticity coordinates.

8. Frequently Asked Questions (Based on Technical Parameters)

8.1 Why is my LED not producing 960 lumens in my prototype?

The 960 lm rating is at Ts=25°C and IF=1000mA. In a real application, the solder pad temperature is likely much higher, reducing the effective flux. Measure or estimate your actual Ts and refer to the "Relative Luminous Flux vs. Junction Temperature" graph to find the expected output. Also, ensure your driver is providing the correct current.

8.2 Can I drive this LED at 1500mA for maximum brightness?

You can only drive it at 1500mA if you can guarantee the solder pad temperature (Ts) is at or below 25°C, which is practically impossible in an enclosed fixture. You must use the derating curve. At a more realistic Ts of 80°C, the maximum allowed current is significantly lower (approximately 1150-1200mA based on curve interpolation).

8.3 How do I interpret the two different thermal resistance values?

Use RthJS_real (2.3 K/W typical) for your thermal calculations. This value is measured under realistic operating power (1000mA), accounting for any temperature-dependent changes in material properties. RthJS_el is measured with a tiny signal and represents a best-case, low-power scenario, which is not representative of actual use.

8.4 Is a heatsink always necessary?

For this power level (approximately 10W electrical input at 1000mA), a heatsink is almost always necessary in an automotive environment. The primary thermal path is through the solder pads into the PCB. The PCB itself must be designed as part of the heatsink, often requiring a metal core or an attached aluminum heatsink.