2020 SMD Super Red LED Datasheet - 2.0x2.0x0.7mm - 2.3V - 0.322W - English Technical Documentation

1. Product Overview

The 2020-SR140DM-AM is a high-performance, surface-mount Super Red LED designed specifically for demanding automotive lighting applications. This component belongs to the \"2020\" product family, denoting its 2.0mm x 2.0mm footprint. Its core advantage lies in the combination of reliable luminous output, a wide 120-degree viewing angle, and robust construction that meets stringent automotive-grade qualifications, including AEC-Q102. The primary target market is automotive exterior and interior lighting systems where consistent color, long-term reliability, and compact size are critical.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The LED's key performance is defined at a standard test current of 140mA. Under these conditions, the typical luminous flux is 18 lumens (lm), with a minimum of 13 lm and a maximum of 27 lm, accounting for production variances. The dominant wavelength is typically 628 nm, placing it firmly in the Super Red spectrum, with a binning range from 627 nm to 639 nm. The forward voltage (Vf) at 140mA is typically 2.3V, ranging from 1.75V to 2.75V. This parameter is crucial for driver design and thermal management, as power dissipation is calculated as Vf * If. At typical conditions, this equates to approximately 0.322W (2.3V * 0.14A).

2.2 Absolute Maximum Ratings and Thermal Properties

To ensure device longevity, operating conditions must never exceed the Absolute Maximum Ratings. The maximum continuous forward current is 250 mA, and the device can handle surge currents up to 1000 mA for very short pulses (≤10 μs). The maximum junction temperature (Tj) is 150°C, while the operating temperature range is specified from -40°C to +125°C, suitable for harsh automotive environments. Thermal management is vital; the thermal resistance from the junction to the solder point (Rth JS) is typically 23 K/W (real) or 16 K/W (electrical), indicating how effectively heat is transferred from the semiconductor die to the PCB.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins.

3.1 Luminous Flux Binning

LEDs are categorized into three flux bins: E6 (13-17 lm), F7 (17-20 lm), and F8 (20-23 lm). The \"M\" in the part number indicates a Medium brightness level, which typically corresponds to the F7 bin.

3.2 Forward Voltage Binning

Four voltage bins are defined: 1720 (1.75-2.0V), 2022 (2.0-2.25V), 2225 (2.25-2.5V), and 2527 (2.5-2.75V). This allows designers to select LEDs with tighter Vf tolerances for current-matching in multi-LED arrays.

3.3 Dominant Wavelength Binning

The color is controlled through wavelength bins: 2730 (627-630 nm), 3033 (630-633 nm), 3336 (633-636 nm), and 3639 (636-639 nm). The typical value of 628 nm falls within the 2730 bin.

4. Performance Curve Analysis

4.1 IV Curve and Relative Luminous Flux

The Forward Current vs. Forward Voltage graph shows a characteristic exponential relationship. The Relative Luminous Flux vs. Forward Current curve demonstrates that light output increases sub-linearly with current, emphasizing the importance of driving at the recommended 140mA for optimal efficiency and lifetime.

4.2 Temperature Dependence

The Relative Luminous Flux vs. Junction Temperature graph shows that light output decreases as temperature increases, a typical behavior for LEDs. The Relative Forward Voltage vs. Junction Temperature curve has a negative slope, meaning Vf decreases as temperature rises, which can be used for temperature sensing. The Relative Wavelength Shift graph indicates a slight increase in dominant wavelength (red shift) with increasing temperature.

4.3 Spectral Distribution and Derating

The Relative Spectral Distribution graph confirms a narrow, peaked emission in the red region (~628 nm). The Forward Current Derating Curve is critical for design: it shows the maximum allowable continuous current must be reduced as the solder pad temperature (Ts) increases. For example, at the maximum Ts of 125°C, the maximum If is 250 mA.

5. Mechanical and Package Information

5.1 Physical Dimensions

The LED has a standard 2020 (2.0mm x 2.0mm) SMD footprint. The overall package height is approximately 0.7mm. Detailed mechanical drawings specify all critical dimensions, including lens size and lead frame placement, with a general tolerance of ±0.1mm.

5.2 Recommended Solder Pad Layout

A land pattern design is provided to ensure reliable soldering and optimal thermal performance. The design includes a central thermal pad for efficient heat transfer to the PCB. Adherence to this layout is recommended to prevent tombstoning and ensure proper alignment.

6. Soldering and Assembly Guidelines

The LED is compatible with standard infrared reflow soldering processes. The maximum soldering temperature is 260°C for a duration not exceeding 30 seconds, as per the IPC/JEDEC J-STD-020 profile. It is classified as Moisture Sensitivity Level (MSL) 2, meaning the device must be baked if exposed to ambient air for more than one year before use. Proper ESD (Electrostatic Discharge) handling procedures must be followed, as the device is rated for 2kV Human Body Model (HBM).

7. Packaging and Ordering Information

The part number follows a specific structure: 2020 - SR - 140 - D - M - AM.

• 2020: Product family (2.0mm x 2.0mm).
• SR: Color (Super Red).
• 140: Test Current in mA.
• D: Lead Frame Type (Au plating with white reflector glue).
• M: Brightness Level (Medium).
• AM: Designates Automotive application.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is explicitly designed for automotive lighting. This includes:

• Exterior Lighting: Center High-Mount Stop Lights (CHMSL), rear combination lamps (stop/tail functions), side marker lights.
• Interior Lighting: Dashboard backlighting, switch illumination, ambient lighting.

8.2 Design Considerations

• Current Driving: Use a constant-current driver, not a constant-voltage source, to ensure stable light output and prevent thermal runaway. The recommended operating point is 140mA.
• Thermal Management: The PCB must be designed to effectively dissipate heat. Use the provided thermal resistance values (Rth JS) to calculate the expected junction temperature rise based on your board's thermal performance and ambient conditions. Keep Tj well below 150°C.
• Optics: The 120° viewing angle is suitable for wide-area illumination. For focused beams, secondary optics (lenses) may be required.
• Sulfur Resistance: The device meets Sulfur Test Class A1, making it suitable for environments with atmospheric sulfur contamination.

9. Technical Comparison and Differentiation

Compared to standard red LEDs, the \"Super Red\" variant offers higher luminous efficacy (more lumens per watt) and a more saturated, deeper red color (lower dominant wavelength around 628nm vs. standard red at 620-625nm or amber-red). The AEC-Q102 qualification, extended temperature range (-40°C to +125°C), and sulfur resistance are key differentiators that justify its use in automotive versus commercial-grade applications. The use of a gold-plated lead frame (type \"D\") enhances reflectivity and long-term reliability.

10. Frequently Asked Questions (FAQs)

Q: Can I drive this LED at 250mA continuously?
A: You can, but only if the solder pad temperature (Ts) is maintained at or below 25°C, as per the derating curve. In most practical automotive applications with higher ambient temperatures, continuous operation at 250mA would likely exceed thermal limits. The recommended operating current is 140mA.

Q: What is the difference between \"real\" and \"electrical\" thermal resistance?
A: Electrical thermal resistance (Rth JS el) is measured using the LED's own Vf temperature coefficient as a sensor. Real thermal resistance (Rth JS real) is measured with an external sensor. The electrical method is more common for LEDs. The datasheet provides both; for most thermal calculations, using the \"real\" value (23 K/W) is more conservative.

Q: How do I interpret the luminous flux binning for ordering?
A: The part number specifies a Medium (M) brightness level. For precise brightness matching in critical applications, you may need to specify a particular flux bin (E6, F7, F8) with your supplier, as the standard \"M\" grade covers a range.

11. Design and Usage Case Study

Scenario: Designing a CHMSL (Center High-Mount Stop Light)
A designer needs 15 LEDs for a CHMSL array. They choose the 2020-SR140DM-AM for its brightness, color, and automotive grade. Using the typical Vf of 2.3V at 140mA, the total voltage drop for a series string of 15 LEDs would be 34.5V, requiring a boost converter from the vehicle's 12V system. Alternatively, they might use parallel strings driven by a single constant-current driver with current-sharing resistors, carefully selecting LEDs from the same Vf bin (e.g., 2022) to ensure even brightness. The PCB layout incorporates the recommended solder pad with a large copper pour connected to the thermal pad for heat sinking. Thermal simulation is run using the Rth JS of 23 K/W and the expected maximum ambient temperature inside the rear window (e.g., 85°C) to verify the junction temperature remains below 110°C for long life.

12. Operating Principle

This is a semiconductor light-emitting diode (LED). When a forward voltage exceeding its bandgap voltage (approximately 2.3V) is applied, electrons and holes recombine in the active region of the semiconductor chip (typically based on AlInGaP materials for red emission). This recombination process releases energy in the form of photons (light). The specific composition of the semiconductor layers determines the wavelength (color) of the emitted light. The epoxy lens encapsulates the chip, provides mechanical protection, and shapes the light output to achieve the 120-degree viewing angle.

13. Technology Trends

The automotive LED market continues to evolve towards higher efficiency (more lumens per watt), enabling lower power consumption and reduced thermal load. There is also a trend towards miniaturization (smaller than 2020 footprint) for sleeker light designs and integration of multiple chips (e.g., RGB) into single packages for adaptive lighting. Furthermore, enhanced reliability standards and testing for new stressors like laser light in LiDAR-rich environments are becoming increasingly important. The move towards standardized digital interfaces (e.g., SPI, I2C) for LED control in complex adaptive driving beam (ADB) headlights is another significant trend, though this particular component remains an analog, current-driven device.