EL 2020 Cube Light LED Datasheet - SMD Package - Cool White - 50lm @ 140mA - 3.0V - 120° Viewing Angle - English Technical Document

1. Product Overview

The EL 2020 Cube Light is a high-performance, surface-mount device (SMD) LED engineered for demanding automotive lighting applications. This component represents a compact and reliable solid-state lighting solution, offering a balance of luminous output, efficiency, and robustness required for modern vehicle systems. Its core design philosophy centers on providing consistent performance under the wide temperature ranges and harsh environmental conditions typical of automotive environments.

The LED is offered in a Cool White color temperature, targeting applications where a bright, neutral-to-slightly blueish white light is desired. The package is designed for automated assembly processes, facilitating high-volume manufacturing. A key advantage of this device is its compliance with the AEC-Q102 stress test qualification for discrete optoelectronic semiconductors, which is the industry standard for automotive-grade components. This ensures a level of reliability and longevity that meets or exceeds automotive OEM requirements.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The primary photometric characteristic is the typical luminous flux of 50 lumens (lm) when driven at a forward current (I_F) of 140 mA. It is crucial to note the specified measurement tolerance of ±8% for luminous flux, which accounts for normal production variations. The minimum and maximum values under the same condition are 45 lm and 70 lm, respectively, defining the performance window.

Electrically, the device exhibits a typical forward voltage (V_F) of 3.0 volts at 140 mA, with a range from 2.75 V to 3.5 V. The forward voltage measurement tolerance is specified as ±0.05V. The device has a wide operating forward current range from a minimum of 10 mA up to an absolute maximum rating of 250 mA. The optical performance is characterized by a wide 120-degree viewing angle (with a tolerance of ±5°), providing a broad, uniform radiation pattern suitable for various lighting optics.

2.2 Thermal and Absolute Maximum Ratings

Thermal management is critical for LED performance and lifetime. The datasheet specifies two thermal resistance values: the real thermal resistance (R_{th JS real}) from the junction to the solder point is typically 24 K/W (max 32 K/W), while the electrically derived value (R_{th JS el}) is typically 17 K/W (max 23 K/W). The lower electrical value often serves as a conservative design guideline.

The absolute maximum ratings define the operational limits that must not be exceeded to prevent permanent damage. Key ratings include:

• Power Dissipation (P_d): 875 mW
• Forward Current (I_F): 250 mA (continuous)
• Surge Current (I_FM): 750 mA for pulses ≤10 μs at a low duty cycle (D=0.005)
• Junction Temperature (T_J): 150 °C
• Operating & Storage Temperature: -40 °C to +125 °C
• ESD Sensitivity (HBM): 8 kV
• Reflow Soldering Temperature: 260°C peak for 30 seconds maximum

Adherence to these limits is essential for reliable operation.

3. Binning System Explanation

To manage production variances and allow for precise system design, the LEDs are sorted into bins based on key parameters.

3.1 Luminous Flux Binning

Luminous flux is categorized into three bins:

• F4: 45 lm (Min) to 52 lm (Max)
• F5: 52 lm (Min) to 60 lm (Max)
• F6: 60 lm (Min) to 70 lm (Max)

The typical value of 50 lm falls within the F4 bin. Designers must select the appropriate bin based on the required light output for their application.

3.2 Forward Voltage Binning

Forward voltage is also binned to aid in driver circuit design and power management:

• 2730: 2.75 V (Min) to 3.0 V (Max)
• 3032: 3.0 V (Min) to 3.25 V (Max)
• 3235: 3.25 V (Min) to 3.5 V (Max)

3.3 Color (Chromaticity) Binning

The Cool White emission is defined within the CIE 1931 color space. The datasheet provides the corner coordinates for four distinct bins (63M, 61M, 58M, 56M) which correspond to correlated color temperature (CCT) ranges:

• 63M: ~6100K to 6600K
• 61M: ~5800K to 6300K
• 58M: ~5600K to 6100K
• 56M: ~5300K to 5800K

A graphical representation on the CIE chromaticity diagram shows these bins as quadrangles. The specified measurement tolerance for color coordinates is ±0.005. This binning ensures color consistency across multiple LEDs in an assembly.

4. Performance Curve Analysis

4.1 IV Curve and Relative Luminous Flux

The Forward Current vs. Forward Voltage graph shows the characteristic exponential relationship. At the typical operating point of 140 mA, V_F is approximately 3.0V. The curve is essential for designing the current-limiting circuitry.

The Relative Luminous Flux vs. Forward Current graph demonstrates that light output is sub-linear with current. While output increases with current, the efficacy (lumens per watt) typically decreases at higher currents due to increased junction temperature and other factors. The curve is normalized to the flux at 140 mA.

4.2 Temperature Dependency

Two critical graphs illustrate performance variation with junction temperature (T_j).

• Relative Luminous Flux vs. Junction Temperature: Shows that light output decreases as T_j increases. Effective heat sinking is paramount to maintain desired brightness.
• Relative Forward Voltage vs. Junction Temperature: Demonstrates that V_F has a negative temperature coefficient, decreasing linearly as T_j rises. This property can sometimes be used for temperature sensing.
• Chromaticity Shift vs. Junction Temperature: Plots the change in CIE x and y coordinates, showing minimal shift across the temperature range, which is important for color stability.

4.3 Spectral Distribution and Radiation Pattern

The Relative Spectral Distribution graph plots intensity against wavelength from 400nm to 800nm. It shows a peak in the blue region (around 450-455nm) from the LED chip's primary emission, with a broader secondary peak in the yellow region (around 550-600nm) generated by the phosphor coating, which combines to produce the Cool White light.

The Typical Diagram of Radiation Characteristics visually represents the 120° viewing angle, showing the angular distribution of luminous intensity relative to the centerline (0°).

4.4 Derating and Pulse Handling

The Forward Current Derating Curve is a vital design tool. It plots the maximum permissible continuous forward current against the solder pad temperature (T_S). As T_S increases, the maximum allowed current must be reduced to prevent exceeding the T_J(max) of 150°C. For example, at a T_S of 125°C, the maximum I_F is 250 mA.

The Permissible Pulse Handling Capability graph defines the peak pulse current (I_FP) allowed for a given pulse width (t_p) and duty cycle (D), with the solder point at 25°C. This is crucial for applications using pulsed driving schemes.

5. Mechanical, Package, and Assembly Information

5.1 Mechanical Dimensions

The datasheet includes a detailed mechanical drawing of the LED package. Key dimensions (in millimeters) define the footprint, height, and lead positions. Tolerances are typically ±0.1mm unless otherwise specified. The drawing is essential for PCB footprint design and ensuring proper fit within the final assembly.

5.2 Recommended Soldering Pad Layout

A separate drawing provides the recommended copper pad pattern on the PCB for optimal soldering. This includes the pad sizes and spacing for the electrical terminals and the thermal pad. Following this recommendation ensures good solder joint formation, proper thermal transfer to the PCB, and mechanical stability.

6. Soldering, Assembly, and Handling Guidelines

6.1 Reflow Soldering Profile

The component is rated for a maximum peak reflow temperature of 260°C for 30 seconds. A typical reflow profile should be used, with controlled preheat, soak, reflow, and cooling phases to minimize thermal shock and ensure reliable solder joints without damaging the LED package or internal materials.

6.2 Precautions for Use

General handling precautions include avoiding mechanical stress on the package, preventing contamination of the lens, and using proper ESD controls during handling and assembly, as the device is rated for 8kV HBM ESD.

6.3 Moisture Sensitivity and Storage

The LED has a Moisture Sensitivity Level (MSL) of 2. This means the package can be exposed to factory floor conditions (≤30°C/60% RH) for up to one year before it requires baking prior to reflow soldering. For longer storage or after the bag is opened, specific baking procedures per IPC/JEDEC standards should be followed to prevent "popcorning" during reflow.

7. Environmental Compliance and Reliability

The device is compliant with RoHS (Restriction of Hazardous Substances) and REACH regulations. It is also specified as Halogen Free, with limits on Bromine (Br) and Chlorine (Cl) content (Br <900 ppm, Cl <900 ppm, Br+Cl <1500 ppm).

A significant reliability feature is its performance in sulfur-rich environments. The device meets Sulfur Test Class A1 criteria, indicating high resistance to corrosion caused by atmospheric sulfur, which is a common concern in automotive and industrial settings.

8. Application Notes and Design Considerations

8.1 Primary Application: Automotive Lighting

The primary intended application is automotive lighting. Potential use cases include interior lighting (dome lights, map lights, footwell lighting, ambient lighting), exterior signaling (center high-mount stop lights - CHMSL), and possibly auxiliary lighting. The AEC-Q102 qualification, wide temperature range, and sulfur resistance make it suitable for these harsh environments.

8.2 Driver Circuit Design

Designers must implement a constant-current driver circuit, not a constant-voltage supply, to ensure stable light output and prevent thermal runaway. The driver should be designed to accommodate the forward voltage bin range. Thermal management is non-negotiable; the PCB must provide an adequate thermal path from the LED's thermal pad to a heatsink or the board's copper planes to keep the junction temperature within safe limits, especially when operating at high currents or in high ambient temperatures.

8.3 Optical Design

The 120° viewing angle offers flexibility. For applications requiring a focused beam, secondary optics (reflectors, lenses) will be necessary. The wide angle is beneficial for applications requiring even, diffuse illumination over an area.

9. Technical Comparison and Positioning

Compared to standard commercial-grade LEDs, the key differentiators of this component are its automotive-grade qualification (AEC-Q102), extended operating temperature range (-40°C to +125°C), and specific resistance to sulfur corrosion. These features come at the expense of higher cost but are mandatory for automotive safety and reliability standards. Within the automotive LED market, its 50lm output at 140mA positions it as a medium-power device suitable for a wide array of applications beyond simple indicator functions.

10. Frequently Asked Questions (FAQs)

Q: What is the typical efficacy (lumens per watt) of this LED?
A: At the typical operating point (140mA, 3.0V, 50lm), the input power is 0.42W (140mA * 3.0V). The efficacy is approximately 119 lm/W (50lm / 0.42W).

Q: Can I drive this LED with a 12V automotive battery directly?
A: No. The LED requires a constant current driver. Connecting it directly to a 12V source would cause excessive current flow, immediately destroying the device. A driver circuit that regulates current to the desired level (e.g., 140mA) is required.

Q: How do I interpret the two different thermal resistance values?
A> Use the higher, "real" thermal resistance value (R_{th JS real} typ. 24 K/W) for conservative thermal design calculations. The electrical value is derived from a measurement technique and is often lower.

Q: What does MSL 2 mean for my production process?
A> MSL 2 means the components can be stored in their sealed, moisture-barrier bag for up to 12 months under controlled conditions (≤30°C/60%RH). Once the bag is opened, you typically have 1 week to complete reflow soldering before the parts may need to be baked.

11. Design and Usage Case Study

Scenario: Designing an automotive interior dome light.
A designer needs a bright, white light for a dome light assembly. They select this LED in the F5 luminous flux bin (52-60 lm) and the 61M color bin (~5800-6300K) for a neutral white appearance. They design a PCB with the exact recommended solder pad layout. A constant-current buck driver IC is selected to provide 140mA from the vehicle's 12V system. Thermal analysis is performed using the derating curve and thermal resistance: if the PCB's thermal management keeps the solder pad below 85°C, the LED can be run at its full 140mA rating. The wide 120° viewing angle is perfect for illuminating the cabin evenly without requiring complex secondary optics. The AEC-Q102 qualification gives confidence in the component's long-term reliability for this automotive application.

12. Operating Principle

This is a phosphor-converted white LED. The core is a semiconductor chip, typically made of indium gallium nitride (InGaN), which emits light in the blue spectrum when electrical current passes through it (electroluminescence). This blue light is partially absorbed by a layer of cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor coating deposited on or near the chip. The phosphor absorbs some blue photons and re-emits light across a broader spectrum, predominantly in the yellow region. The mixture of the remaining blue light and the converted yellow light is perceived by the human eye as white light. The exact ratio of blue to yellow emission, controlled by the phosphor composition and thickness, determines the correlated color temperature (CCT), resulting in the "Cool White" output specified.

13. Technology Trends

The general trend in automotive LED lighting is toward higher efficiency (more lumens per watt), higher power density, and improved reliability. There is also a drive for more precise color control and higher Color Rendering Index (CRI) for better visual perception. Integration is another trend, with multi-chip packages and packages with integrated drivers or control circuits becoming more common. Furthermore, there is increasing focus on smart, adaptive lighting systems, which may require LEDs capable of very fast switching or dimming. While this datasheet describes a discrete, single-die component, the underlying technology continues to evolve to meet these demands for future automotive lighting systems, including advanced forward lighting and dynamic signal lighting.