Table of Contents
- 1. Product Overview
- 2. In-Depth Technical Parameter Analysis
- 2.1 Photometric and Electrical Characteristics
- 2.2 Thermal and Absolute Maximum Ratings
- 3. Binning System Explanation
- 3.1 Luminous Flux Binning
- 3.2 Forward Voltage Binning
- 3.3 Color (Chromaticity) Binning
- 4. Performance Curve Analysis
- 4.1 IV Curve and Relative Luminous Flux
- 4.2 Temperature Dependence
- 4.3 Spectral Distribution and Derating
- 5. Mechanical and Package Information
- 6. Soldering and Assembly Guidelines
- 6.1 Recommended Soldering Pad and Reflow Profile
- 6.2 Precautions for Use
- 7. Packaging and Ordering Information
1. Product Overview
The ALFS2G-C0 series represents a high-performance, surface-mount LED component engineered for demanding automotive lighting applications. It is housed in a robust ceramic package, offering superior thermal management and reliability essential for the harsh operating environments of vehicles. The primary design focus is on delivering high luminous output with consistent performance across a wide temperature range, making it a suitable choice for safety-critical exterior lighting functions.
Its core advantages include compliance with stringent automotive industry standards such as AEC-Q102, ensuring long-term reliability. The product also meets environmental regulations including RoHS, REACH, and halogen-free requirements, reflecting a commitment to ecological design. The ceramic substrate provides excellent sulfur robustness (Class A1), a critical feature for preventing corrosion in polluted atmospheres, and a high ESD protection rating of up to 8 kV enhances its durability during handling and assembly.
The target market is squarely within the automotive sector, specifically for exterior lighting modules. Its performance characteristics are tailored to meet the precise optical, thermal, and longevity demands of modern vehicle lighting systems.
2. In-Depth Technical Parameter Analysis
2.1 Photometric and Electrical Characteristics
The key operational parameters define the LED's performance envelope. The typical luminous flux (Φv) is 860 lumens when driven at a forward current (IF) of 1000 mA, with a specified tolerance of ±8%. This measurement is standardized at a thermal pad temperature of 25°C. The forward voltage (VF) at this drive current has a typical value of 6.5 V, with a minimum of 5.8 V and a maximum of 7.6 V, and a measurement tolerance of ±0.05 V. The wide viewing angle of 120 degrees ensures a broad, uniform light distribution, suitable for applications like daytime running lights (DRL) and fog lamps. The correlated color temperature (CCT) for the cool white variant spans a range from 5180 K to 6893 K under typical operating conditions.
2.2 Thermal and Absolute Maximum Ratings
Thermal management is paramount for LED longevity. The thermal resistance from the junction to the solder point (Rth JS) is a critical parameter, with an electrical measurement value of 1.9 K/W (typ.) and a real measurement value of 2.7 K/W (typ.). This indicates the efficiency of heat transfer from the semiconductor die to the printed circuit board.
The Absolute Maximum Ratings define the limits beyond which permanent damage may occur. The maximum permissible forward current is 1500 mA. The maximum junction temperature (TJ) is 150°C. The device is rated for an operating temperature range (Topr) of -40°C to +125°C and a storage temperature range (Tstg) of -40°C to +125°C. It is crucial to note that the device is not designed for reverse voltage operation. The maximum power dissipation (Pd) is 11.4 W. The component can withstand a reflow soldering temperature of 260°C, compatible with standard lead-free soldering processes.
3. Binning System Explanation
To ensure color and brightness consistency in production, LEDs are sorted into bins based on key parameters.
3.1 Luminous Flux Binning
For the Cool White version, luminous flux is categorized into groups and bins. Group D includes bins 7 (700-750 lm) and 8 (750-800 lm). Group E includes bins 1 (800-860 lm) and 2 (860-920 lm). The typical part (860 lm) falls into Bin E1. All measurements have a tolerance of ±8% and are taken with a 25ms current pulse at the typical forward current.
3.2 Forward Voltage Binning
Forward voltage is binned into three groups to aid in circuit design for consistent current drive. Group 2A ranges from 5.80 V to 6.40 V. Group 2B ranges from 6.40 V to 7.00 V. Group 2C ranges from 7.00 V to 7.60 V. Measurement tolerance is ±0.05V.
3.3 Color (Chromaticity) Binning
The color coordinates are binned according to an ECE (Economic Commission for Europe) structure, which is standard for automotive lighting. The provided chart and table define specific quadrilateral regions on the CIE 1931 chromaticity diagram for various bins (e.g., 64A, 64B, 60A, 60B). Each bin is defined by four (x, y) coordinate pairs that form its boundaries. These bins correspond to correlated color temperature ranges, such as 6240-6530K for bins 64A/B and 5850-6240K for bins 60A/B. This precise binning ensures that all LEDs used in a single lighting assembly will have nearly identical color appearance.
4. Performance Curve Analysis
The datasheet provides several graphs illustrating the relationship between key parameters, which are essential for design engineers.
4.1 IV Curve and Relative Luminous Flux
The Forward Current vs. Forward Voltage curve shows a non-linear relationship, typical for LEDs. The voltage increases with current, and designers must account for this when selecting current drivers. The Relative Luminous Flux vs. Forward Current graph demonstrates that light output increases with drive current but will eventually saturate. Operating at 1000mA provides a good balance of efficiency and output.
4.2 Temperature Dependence
The Relative Luminous Flux vs. Junction Temperature graph is critical. It shows that light output decreases as the junction temperature rises. At the maximum rated junction temperature of 150°C, the relative luminous flux is approximately 60% of its value at 25°C. This underscores the importance of effective heat sinking. The Relative Forward Voltage vs. Junction Temperature curve shows a negative temperature coefficient; forward voltage decreases as temperature increases. This can be used for indirect temperature monitoring in some applications. The Chromaticity Shift graphs show minimal change in color coordinates with varying current and temperature, indicating good color stability.
4.3 Spectral Distribution and Derating
The Relative Spectral Distribution curve defines the light's color characteristics. For a cool white LED, it shows a peak in the blue region (from the LED chip) and a broad emission in the yellow/red region (from the phosphor). The Forward Current Derating Curve is a vital design tool. It plots the maximum allowable forward current against the solder pad temperature (Ts). For example, at a Ts of 85°C, the maximum IF is 1500mA. At the maximum Ts of 125°C, the maximum IF derates to 500mA. The curve also specifies that the device should not be operated below 50mA.
5. Mechanical and Package Information
The LED utilizes a Surface-Mount Device (SMD) ceramic package. While specific dimensions are not detailed in the provided excerpt, a typical datasheet would include a detailed mechanical drawing with length, width, height, and lead/pad positions. The ceramic construction offers superior thermal conductivity compared to plastic packages, directly supporting the low thermal resistance and high-power capability. The Moisture Sensitivity Level (MSL) is rated at 2, indicating the component can be stored for up to one year at <30°C/60% RH before requiring baking prior to reflow soldering.
6. Soldering and Assembly Guidelines
6.1 Recommended Soldering Pad and Reflow Profile
A recommended solder pad layout is provided to ensure reliable electrical connection and optimal heat transfer from the package to the PCB. Adhering to this layout is crucial for performance and reliability. The reflow soldering profile is specified to withstand a peak temperature of 260°C. The profile will detail the preheat, soak, reflow, and cooling stages with specific time and temperature constraints to prevent thermal shock and ensure proper solder joint formation without damaging the LED component.
6.2 Precautions for Use
General precautions include avoiding mechanical stress on the package, preventing electrostatic discharge (ESD) during handling (despite its 8kV rating), and ensuring the soldering process does not exceed the specified profile. Proper storage according to the MSL rating is also necessary to prevent "popcorning" during reflow.
7. Packaging and Ordering Information
The packaging information section details how the components are supplied, typically on tape and reel for automated assembly. The ordering information clarifies the part number structure. Based on the provided number "ALFS2G-C010001H-AM\
LED Specification Terminology
Complete explanation of LED technical terms
Photoelectric Performance
| Term | Unit/Representation | Simple Explanation | Why Important |
|---|---|---|---|
| Luminous Efficacy | lm/W (lumens per watt) | Light output per watt of electricity, higher means more energy efficient. | Directly determines energy efficiency grade and electricity cost. |
| Luminous Flux | lm (lumens) | Total light emitted by source, commonly called "brightness". | Determines if the light is bright enough. |
| Viewing Angle | ° (degrees), e.g., 120° | Angle where light intensity drops to half, determines beam width. | Affects illumination range and uniformity. |
| CCT (Color Temperature) | K (Kelvin), e.g., 2700K/6500K | Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool. | Determines lighting atmosphere and suitable scenarios. |
| CRI / Ra | Unitless, 0–100 | Ability to render object colors accurately, Ra≥80 is good. | Affects color authenticity, used in high-demand places like malls, museums. |
| SDCM | MacAdam ellipse steps, e.g., "5-step" | Color consistency metric, smaller steps mean more consistent color. | Ensures uniform color across same batch of LEDs. |
| Dominant Wavelength | nm (nanometers), e.g., 620nm (red) | Wavelength corresponding to color of colored LEDs. | Determines hue of red, yellow, green monochrome LEDs. |
| Spectral Distribution | Wavelength vs intensity curve | Shows intensity distribution across wavelengths. | Affects color rendering and quality. |
Electrical Parameters
| Term | Symbol | Simple Explanation | Design Considerations |
|---|---|---|---|
| Forward Voltage | Vf | Minimum voltage to turn on LED, like "starting threshold". | Driver voltage must be ≥Vf, voltages add up for series LEDs. |
| Forward Current | If | Current value for normal LED operation. | Usually constant current drive, current determines brightness & lifespan. |
| Max Pulse Current | Ifp | Peak current tolerable for short periods, used for dimming or flashing. | Pulse width & duty cycle must be strictly controlled to avoid damage. |
| Reverse Voltage | Vr | Max reverse voltage LED can withstand, beyond may cause breakdown. | Circuit must prevent reverse connection or voltage spikes. |
| Thermal Resistance | Rth (°C/W) | Resistance to heat transfer from chip to solder, lower is better. | High thermal resistance requires stronger heat dissipation. |
| ESD Immunity | V (HBM), e.g., 1000V | Ability to withstand electrostatic discharge, higher means less vulnerable. | Anti-static measures needed in production, especially for sensitive LEDs. |
Thermal Management & Reliability
| Term | Key Metric | Simple Explanation | Impact |
|---|---|---|---|
| Junction Temperature | Tj (°C) | Actual operating temperature inside LED chip. | Every 10°C reduction may double lifespan; too high causes light decay, color shift. |
| Lumen Depreciation | L70 / L80 (hours) | Time for brightness to drop to 70% or 80% of initial. | Directly defines LED "service life". |
| Lumen Maintenance | % (e.g., 70%) | Percentage of brightness retained after time. | Indicates brightness retention over long-term use. |
| Color Shift | Δu′v′ or MacAdam ellipse | Degree of color change during use. | Affects color consistency in lighting scenes. |
| Thermal Aging | Material degradation | Deterioration due to long-term high temperature. | May cause brightness drop, color change, or open-circuit failure. |
Packaging & Materials
| Term | Common Types | Simple Explanation | Features & Applications |
|---|---|---|---|
| Package Type | EMC, PPA, Ceramic | Housing material protecting chip, providing optical/thermal interface. | EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life. |
| Chip Structure | Front, Flip Chip | Chip electrode arrangement. | Flip chip: better heat dissipation, higher efficacy, for high-power. |
| Phosphor Coating | YAG, Silicate, Nitride | Covers blue chip, converts some to yellow/red, mixes to white. | Different phosphors affect efficacy, CCT, and CRI. |
| Lens/Optics | Flat, Microlens, TIR | Optical structure on surface controlling light distribution. | Determines viewing angle and light distribution curve. |
Quality Control & Binning
| Term | Binning Content | Simple Explanation | Purpose |
|---|---|---|---|
| Luminous Flux Bin | Code e.g., 2G, 2H | Grouped by brightness, each group has min/max lumen values. | Ensures uniform brightness in same batch. |
| Voltage Bin | Code e.g., 6W, 6X | Grouped by forward voltage range. | Facilitates driver matching, improves system efficiency. |
| Color Bin | 5-step MacAdam ellipse | Grouped by color coordinates, ensuring tight range. | Guarantees color consistency, avoids uneven color within fixture. |
| CCT Bin | 2700K, 3000K etc. | Grouped by CCT, each has corresponding coordinate range. | Meets different scene CCT requirements. |
Testing & Certification
| Term | Standard/Test | Simple Explanation | Significance |
|---|---|---|---|
| LM-80 | Lumen maintenance test | Long-term lighting at constant temperature, recording brightness decay. | Used to estimate LED life (with TM-21). |
| TM-21 | Life estimation standard | Estimates life under actual conditions based on LM-80 data. | Provides scientific life prediction. |
| IESNA | Illuminating Engineering Society | Covers optical, electrical, thermal test methods. | Industry-recognized test basis. |
| RoHS / REACH | Environmental certification | Ensures no harmful substances (lead, mercury). | Market access requirement internationally. |
| ENERGY STAR / DLC | Energy efficiency certification | Energy efficiency and performance certification for lighting. | Used in government procurement, subsidy programs, enhances competitiveness. |