2820 SMD LED Datasheet - Package 2.8x2.0mm - Amber Color - 3.0V Typ. - 0.45W @ 150mA - English Technical Documentation

1. Product Overview

The 2820-PA1501M-AM series is a high-performance, surface-mount LED designed primarily for demanding automotive lighting applications. It utilizes a phosphor-converted technology to produce a stable amber color output. The device is housed in a compact 2.8mm x 2.0mm SMD package, offering a balance between size and light output. Its core advantages include compliance with the stringent AEC-Q102 automotive qualification standard, high electrostatic discharge (ESD) protection of 8KV (HBM), and adherence to environmental regulations such as RoHS, REACH, and halogen-free requirements. The target market is automotive interior and exterior lighting, where reliability, color consistency, and performance under harsh conditions are paramount.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The LED's performance is characterized under a standard test current of 150 mA. The typical luminous flux is 45 lumens (lm), with a minimum of 39 lm and a maximum of 60 lm as per the binning structure. The forward voltage (Vf) at this current is typically 3.00 volts, ranging from 2.75V to 3.5V. This parameter is crucial for driver design and thermal management. The device offers a wide viewing angle of 120 degrees, providing a broad and uniform light distribution. The chromaticity coordinates are centered around CIE x=0.575 and CIE y=0.418, defining its specific amber hue. All photometric measurements have a tolerance of ±8%, and forward voltage measurements have a tolerance of ±0.05V.

2.2 Absolute Maximum Ratings and Thermal Properties

To ensure long-term reliability, the device must not be operated beyond its absolute maximum ratings. The maximum continuous forward current is 350 mA, with a peak surge current (tp ≤ 10 μs) capability of 750 mA. The maximum power dissipation is 1225 mW. The junction temperature (Tj) must not exceed 150°C, with an operating temperature range of -40°C to +125°C. Two thermal resistance values are provided: the real thermal resistance from junction to solder point (Rth JS real) is a maximum of 22 K/W, while the electrical method-derived value (Rth JS el) is a maximum of 15 K/W. These values are critical for calculating the necessary heatsinking to maintain Tj within safe limits during operation.

3. Binning System Explanation

The LEDs are sorted into bins to ensure consistency in key parameters for application design.

3.1 Luminous Flux Binning

Flux bins are designated F3, F4, and F5. The F3 bin covers luminous flux from 39 lm to 45 lm, F4 from 45 lm to 52 lm, and F5 from 52 lm to 60 lm. This allows designers to select LEDs based on the required brightness level for their specific application.

3.2 Forward Voltage Binning

Voltage bins help in matching LEDs for current sharing in multi-LED arrays. The bins are 2730 (2.75V - 3.00V), 3032 (3.00V - 3.25V), and 3235 (3.25V - 3.50V). Using LEDs from the same or closely matched voltage bins minimizes current imbalance.

3.3 Color Binning

The amber color is tightly controlled within two primary bins: YA and YB. Each bin is defined by a quadrilateral area on the CIE 1931 chromaticity diagram. Bin YA and YB have specific coordinate boundaries ensuring the emitted amber color falls within a visually consistent and acceptable range. The typical coordinates provided (x=0.575, y=0.418) serve as a central reference point.

4. Performance Curve Analysis

4.1 IV Curve and Relative Luminous Flux

The Forward Current vs. Forward Voltage graph shows the exponential relationship typical of LEDs. At 150 mA, the Vf is centered around 3.0V. The Relative Luminous Flux vs. Forward Current graph indicates that light output increases sub-linearly with current. While driving at higher currents yields more light, it also generates more heat, impacting efficiency and longevity.

4.2 Temperature Dependence

The performance graphs versus junction temperature are critical for automotive applications. The Relative Luminous Flux vs. Junction Temperature curve shows that light output decreases as temperature increases. At 125°C, the relative flux is approximately 70-80% of its value at 25°C. The Forward Voltage has a negative temperature coefficient, decreasing linearly with rising temperature. The Chromaticity Coordinates Shift graphs show minimal change with both increasing current and temperature, indicating good color stability.

4.3 Spectral Distribution and Radiation Pattern

The Relative Spectral Distribution graph confirms a phosphor-converted spectrum, typical for amber LEDs, with a broad emission peak. The viewing angle diagram illustrates the Lambertian-like emission pattern with 120° full width at half maximum (FWHM), confirming the wide, uniform light distribution.

4.4 Derating and Pulse Handling

The Forward Current Derating Curve dictates the maximum allowable continuous current based on the solder pad temperature (Ts). For example, at Ts=125°C, the maximum IF is 350 mA. The curve mandates a minimum operating current of 20 mA. The Permissible Pulse Handling Capability graph defines the peak pulse current (IFP) allowed for very short pulse widths (tp) and various duty cycles (D), which is useful for PWM dimming or strobe applications.

5. Mechanical and Package Information

5.1 Physical Dimensions

The LED package has dimensions of 2.8mm in length and 2.0mm in width. The mechanical drawing provides detailed measurements including overall height, lens geometry, and lead dimensions. All tolerances are ±0.1mm unless otherwise specified. The compact size facilitates high-density PCB layouts.

5.2 Recommended Solder Pad Layout

A land pattern design is provided to ensure reliable soldering and optimal thermal performance. The design includes pads for the two electrical terminals and a central thermal pad. The thermal pad is essential for efficient heat transfer from the LED junction to the PCB. Adhering to this recommended layout helps prevent tombstoning, improves solder joint reliability, and maximizes thermal dissipation.

5.3 Polarity Identification

The cathode is typically marked on the device, often by a notch, a dot, or a green marking on the package underside as indicated in the mechanical drawing. Correct polarity orientation during assembly is mandatory to prevent device damage.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The LED is rated for a maximum soldering temperature of 260°C for 30 seconds. A detailed reflow profile should be followed, typically including preheat, thermal soak, reflow (with peak temperature not exceeding 260°C), and cooling stages. The profile must be compatible with JEDEC standards for moisture sensitivity level (MSL) 2 components, meaning the device must be baked if exposed to ambient conditions beyond its floor life before reflow.

6.2 Precautions for Use

Key precautions include: avoiding mechanical stress on the lens, preventing contamination of the optical surface, using appropriate ESD handling procedures, and ensuring the PCB and solder paste are clean to prevent sulfur-induced corrosion (the device meets Sulfur Test Class A1).

6.3 Storage Conditions

The storage temperature range is -40°C to +125°C. For long-term storage, components should be kept in their original moisture-barrier bags with desiccant if the bag has been opened and the exposure time exceeds the MSL 2 floor life.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The LEDs are supplied on tape and reel for automated assembly. The packaging information details the reel dimensions, tape width, pocket spacing, and orientation of components on the tape.

7.2 Part Number and Model Naming Rules

The part number 2820-PA1501M-AM follows a logical structure: "2820" indicates the package size, "PA" likely stands for Phosphor-converted Amber, "150" may refer to the nominal test current in mA, "1M" could denote a specific flux/color bin or version, and "AM" confirms the amber color. The ordering information allows selection of specific bins for luminous flux (F3/F4/F5) and forward voltage (2730/3032/3235) to meet precise application requirements.

8. Application Recommendations

8.1 Typical Application Scenarios

The primary application is automotive lighting. This includes interior applications such as dashboard backlighting, switch illumination, and ambient lighting. Exterior applications include side marker lights, turn signal indicators (depending on local regulations and required luminous intensity), and daytime running lights (DRLs) when used in clusters or with appropriate optics.

8.2 Design Considerations

Designers must consider several factors: Thermal Management: Use the thermal resistance values and derating curve to design an adequate PCB heatsink (copper pour) and possibly consider the use of metal-core PCBs (MCPCBs) for high-power or high-ambient-temperature applications. Current Drive: Use a constant current driver for stable light output. The driver should be designed to accommodate the forward voltage bin range. Optics: The 120° viewing angle may require secondary optics (lenses, light guides) to achieve desired beam patterns for specific applications. PCB Layout: Follow the recommended solder pad design closely, especially for the thermal pad connection, which should be connected to a large copper area with multiple vias to inner or bottom layers for heat spreading.

9. Technical Comparison and Differentiation

Compared to standard commercial-grade LEDs, the 2820-PA1501M-AM series differentiates itself through its automotive-grade qualification (AEC-Q102). This involves more rigorous testing for temperature cycling, humidity resistance, high-temperature operating life (HTOL), and other stressors. The 8KV ESD rating is higher than typical commercial parts. Its sulfur resistance (Class A1) is a key advantage in automotive and industrial environments where atmospheric sulfur can corrode silver-plated components. The combination of a relatively high flux output (45 lm typ) from a small 2820 package offers good luminous efficacy and design flexibility.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED at 350 mA continuously?
A: You can only drive it at 350 mA if the solder pad temperature (Ts) is at or below 25°C, as per the derating curve. In a real-world application with higher Ts, the maximum allowable continuous current will be lower. Always consult the derating curve.

Q: What is the difference between Rth JS real and Rth JS el?
A: Rth JS real is measured using a temperature-sensitive parameter (like forward voltage) and represents the actual thermal path. Rth JS el is calculated from electrical parameters and is often lower. For conservative thermal design, use the higher Rth JS real value (22 K/W max).

Q: How do I select the right bin?
A: For applications requiring consistent brightness, specify a tight luminous flux bin (e.g., F4). For arrays where current sharing is critical, specify a tight forward voltage bin. For color-critical applications, specify the color bin (YA or YB).

Q: Is this LED suitable for PWM dimming?
A: Yes, the pulse handling capability graph shows it can handle high peak currents at low duty cycles. Ensure the pulse width and frequency are within the specified limits to avoid overheating.

11. Practical Design and Usage Examples

Example 1: Automotive Interior Ambient Lighting Strip: A design uses 20 LEDs in series on a flexible PCB. The designer selects the F4 flux bin for consistent brightness and the 3032 voltage bin for good matching. A constant-current driver supplying 150 mA is used. The flexible PCB is attached to a metal chassis for heat sinking, keeping Ts below 80°C, which allows a safe operating current per the derating curve.

Example 2: Exterior Side Marker Light: The design uses 3 LEDs. Due to higher under-hood ambient temperatures, the designer uses a metal-core PCB (MCPCB). Thermal simulation is performed using Rth JS real = 22 K/W and the expected ambient temperature to ensure Tj remains below 125°C. The wide 120° viewing angle eliminates the need for a secondary diffuser lens, simplifying the housing design.

12. Operational Principle Introduction

This LED is a phosphor-converted type. The core semiconductor chip emits light at a short wavelength (typically blue or near-UV). This light is absorbed by a layer of phosphor material deposited on or around the chip. The phosphor then re-emits light at longer wavelengths. By carefully selecting the phosphor composition, the combined light from the chip and the phosphor is perceived as amber. This method allows for precise control over the color point and often provides better stability and consistency compared to direct-emitting colored LEDs (like AlInGaP for amber/red). The surface-mount package integrates the chip, phosphor, and a molded silicone or epoxy lens that shapes the light output and provides environmental protection.

13. Technology Trends and Developments

The trend in automotive LED lighting is towards higher efficiency (more lumens per watt), greater power density (more light from smaller packages), and improved reliability under extreme conditions. Phosphor technology continues to advance, offering higher conversion efficiency and better color stability over temperature and time. Packaging technologies are evolving to improve thermal performance, allowing higher drive currents without compromising lifetime. Furthermore, integration of driver electronics and multiple LED chips into single modules is a growing trend. The adherence to standards like AEC-Q102 and specific sulfur resistance tests reflects the industry's push for quantified and guaranteed reliability in harsh automotive environments.