1. Product Overview
The 2820-SR2001M-AM series represents a high-performance, surface-mount LED component engineered specifically for demanding automotive lighting environments. This device is part of a product family characterized by its compact 2820 footprint (2.8mm x 2.0mm), offering a compelling balance of luminous output, reliability, and form factor. The core application is automotive lighting, where consistent performance under harsh conditions is paramount. Its key advantages include compliance with stringent automotive qualification standards like AEC-Q102, robust construction for high-reliability soldering processes, and a design optimized for thermal management, ensuring stable light output over the operational temperature range.
1.1 Core Features and Compliance
The LED is packaged in a standard SMD (Surface Mount Device) format, facilitating automated assembly processes. It emits in the Super Red spectrum with a typical dominant wavelength of 632 nanometers. A primary performance metric is its typical luminous flux of 27 lumens when driven at a forward current of 200 milliamperes. The device offers a wide 120-degree viewing angle, providing broad illumination. It is designed with a degree of robustness against electrostatic discharge, rated for 2kV (Human Body Model). The component is rated MSL 2 (Moisture Sensitivity Level 2), indicating its shelf life and handling requirements before reflow soldering. Crucially, it is qualified according to the AEC-Q102 Rev A standard, which is the stress test qualification for discrete optoelectronic semiconductors in automotive applications. It also meets Sulfur Test Criteria Class A1, offering resistance to corrosive sulfur-containing atmospheres. The product is compliant with RoHS (Restriction of Hazardous Substances) and REACH regulations, and is manufactured to be Halogen Free, with bromine and chlorine content below specified limits (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).
2. Uchambuzi wa Vigezo vya Kiufundi
Sehemu hii inatoa tafsiri ya kina na ya kitu, ya vigezo muhimu vya umeme, vya macho na vya joto vilivyobainishwa kwenye karatasi ya data, na kuelezea umuhimu wake kwa wahandisi wa kubuni.
2.1 Photometric and Optical Characteristics
The primary optical characteristic is the Luminous Flux (Iv), with a typical value of 27 lumens at a forward current (IF) of 200mA. The minimum and maximum values are specified as 20 lm and 33 lm, respectively, under the same condition. This range is directly linked to the binning structure discussed later. The Dominant Wavelength (λd) is typically 632 nm, defining the perceived color of the Super Red light, with a range from 627 nm to 639 nm. The Viewing Angle (φ) is specified as 120 degrees, which is the full angle at which the luminous intensity is half of the peak intensity. This wide angle is beneficial for applications requiring diffuse or area lighting rather than a focused beam.
2.2 Electrical Characteristics
The Forward Voltage (VF) is a critical parameter for driver design. At 200mA, the typical VF is 2.3 volts, with a range from 2.00V to 2.75V. This variance necessitates proper voltage binning for consistent system performance. The Forward Current (IF) has a recommended operating range of 25mA to 250mA, with 200mA being the test condition for most specifications. Exceeding the absolute maximum rating of 250mA can lead to permanent damage. The device is not designed for reverse operation, meaning applying a reverse voltage can cause immediate failure; therefore, circuit protection (like a series diode in parallel arrays) is essential if reverse bias is possible.
2.3 Thermal and Reliability Ratings
Thermal management is crucial for LED longevity and performance. The Thermal Resistance from the junction to the solder point is given by two values: a real thermal resistance (Rth JS real) of 18 K/W (typical) and an electrical method-derived value (Rth JS el) of 12 K/W (typical). Designers should use the real thermal resistance for more accurate junction temperature calculations. The Junction Temperature (TJ) must not exceed 150°C. The Operating Temperature (Topr) Range is from -40°C to +125°C, suitable for automotive under-hood and exterior applications. The Power Dissipation (Pd) absolute maximum is 687.5 mW. The device can withstand a Surge Current (IFM) of 1000 mA for very short pulses (t <= 10 μs, duty cycle 0.005), which is relevant for inrush or transient conditions. The maximum Reflow Soldering Temperature is 260°C for 30 seconds, defining the peak temperature profile during assembly.
3. Binning System Explanation
To ensure color and brightness consistency in production, LEDs are sorted into bins. The 2820-SR2001M-AM uses a three-dimensional binning system.
3.1 Luminous Flux Binning
Luminous flux is sorted into three bins: E8 (20-23 lm), E9 (23-27 lm), and F1 (27-33 lm). The "M" in the part number indicates a Medium brightness level, which typically corresponds to the central bin (E9). Designers must select the appropriate bin based on the required minimum light output for their application, considering the 8% measurement tolerance.
3.2 Forward Voltage Binning
Forward voltage is binned to aid in current matching, especially when LEDs are connected in parallel. The bins are: 2022 (2.00-2.25V), 2225 (2.25-2.50V), and 2527 (2.50-2.75V). Using LEDs from the same voltage bin in a parallel configuration helps ensure more uniform current distribution and brightness.
3.3 Dominant Wavelength Binning
Color consistency is managed through dominant wavelength bins, grouped in 3nm steps: 2730 (627-630 nm), 3033 (630-633 nm), 3336 (633-636 nm), and 3639 (636-639 nm). The typical 632 nm value falls within the 3033 or 3336 bins. For applications where precise color matching is critical, specifying a tight wavelength bin is necessary.
4. Performance Curve Analysis
The datasheet provides several graphs that illustrate the device's behavior under varying conditions, which are essential for robust system design.
4.1 Forward Current vs. Forward Voltage (IV Curve)
The graph shows the exponential relationship between forward current and forward voltage. At the typical operating point of 200mA, the voltage is approximately 2.3V. This curve is vital for designing the current-limiting circuitry, whether using a simple resistor or a constant-current driver. The slope indicates the dynamic resistance of the LED.
4.2 Relative Luminous Flux vs. Forward Current
This graph demonstrates that light output increases super-linearly with current up to a point. While driving at higher currents yields more light, it also generates more heat, which can reduce efficiency and lifespan. The 200mA test point is a good balance between output and reliability for this device.
4.3 Temperature Dependency Graphs
Three key graphs show performance variation with junction temperature: Relative Forward Voltage vs. Junction Temperature shows VF decreases linearly with increasing temperature (approximately -2 mV/°C), which can be used for crude temperature sensing. Relative Luminous Flux vs. Junction Temperature shows that light output decreases as temperature rises, a characteristic of all LEDs. Effective heat sinking is required to maintain stable brightness. Relative Wavelength Shift vs. Junction Temperature indicates the dominant wavelength shifts slightly with temperature (typically 0.1 nm/°C for red LEDs), which is usually negligible for most applications but may be relevant for color-critical uses.
4.4 Forward Current Derating Curve
Wannan shine ɗaya daga cikin mahimman zane-zane don amintacce. Yana nuna matsakaicin izinin gaba na gaba a matsayin aikin zafin fakitin solder. Yayin da zafin fakitin ke ƙaruwa, matsakaicin izinin naɗewa yana raguwa a layi. Misali, a matsakaicin zafin fakitin solder na 125°C, matsakaicin izinin naɗewa shine 250mA (matsakaicin matsakaicin ƙididdiga). Don tabbatar da dogon rayuwa, ana ba da shawarar aiki da ƙasa da wannan layin rage ƙima. Har ila yau, lanƙwasa ta ƙayyadad da ƙaramin ƙarfin aiki na 25mA.
4.5 Permissible Pulse Handling Capability
This graph defines the maximum allowable non-repetitive or repetitive pulse current for a given pulse width (tp) and duty cycle (D). It allows designers to understand the LED's capability to handle short, high-current pulses, which is useful for PWM dimming or transient conditions. The curves show that for very short pulses (e.g., 10 μs), the current can significantly exceed the DC maximum rating.
4.6 Spectral Distribution and Radiation Pattern
The relative spectral distribution graph shows a narrow peak around 632 nm, characteristic of a high-efficiency red LED. The typical radiation pattern diagram (not fully detailed in the provided excerpt but referenced) would illustrate the spatial distribution of light, confirming the 120° viewing angle with a Lambertian or similar pattern.
5. Mechanical and Packaging Information
5.1 Mechanical Dimensions
The LED uses the standard 2820 package outline. The dimensions are provided in a detailed drawing (implied by section 3). Key features include the overall length and width (2.8mm x 2.0mm), the lens geometry, and the location of the cathode and anode terminals. The cathode is typically marked by a visual indicator such as a notch, cut corner, or dot on the package. Tolerances for non-critical dimensions are ±0.1mm.
5.2 Recommended Soldering Pad Layout
Section 4 provides a land pattern design for the PCB. Adhering to this recommended footprint is critical for reliable soldering, proper thermal transfer, and preventing tombstoning during reflow. The design includes pads for the two electrical terminals and a central thermal pad. The thermal pad is essential for conducting heat away from the LED junction to the PCB copper, which acts as a heat sink. The dimensions ensure correct solder fillet formation and component alignment.
6. Soldering and Assembly Guidelines
6.1 Reflow Soldering Profile
The device is compatible with standard infrared or convection reflow soldering processes. The specified maximum condition is a peak temperature of 260°C for 30 seconds. A typical lead-free profile should be used, with preheat, soak, reflow, and cooling stages carefully controlled to avoid thermal shock and ensure proper solder joint formation. The MSL 2 rating means the component must be baked if exposed to ambient air for longer than its specified floor life (typically 1 year when stored at <10% RH and <30°C) before being subjected to reflow.
6.2 Precautions for Use
Gabaɗaya ƙa'idodin kulawa suna aiki: guji matsin inji akan ruwan tabarau, kare daga fitar da wutar lantarki ta amfani da ingantattun sarrafawa na ESD (ko da tare da ƙimar 2kV), kuma adana a cikin busassun yanayi, sarrafawa bisa ga ƙimar MSL. Yayin siyarwa, tabbatar da kushin zafi ya yi kyakkyawar hulɗa tare da kushin PCB don haɓaka zubar da zafi.
7. Packaging and Ordering Information
7.1 Part Number Decoding
The part number 2820-SR2001M-AM is structured as follows: 2820: Product family and package size (2.8mm x 2.0mm). SR: Color code for Super Red. 200: Test current in milliamperes (200mA). 1: Lead frame type (1 = Gold-plated). MBrightness level (M = Medium, corresponding to a specific luminous flux bin). AMDesignates Automotive application and qualification.
7.2 Color Code Reference
The datasheet includes a comprehensive table mapping color symbols to descriptions (e.g., SR=Super Red, UR=Red, UG=Green, UB=Blue, C=Cool White, WW=Warm White, PA=Phosphor Converted Amber). This allows identification of other variants in the same 2820 package family.
7.3 Packaging Information
LEDs are supplied on tape and reel for automated pick-and-place assembly. Standard reel quantities (e.g., 2000 or 4000 pieces per reel) and tape dimensions are provided to configure feeders on assembly machines correctly.
8. Application Suggestions and Design Considerations
8.1 Typical Application Scenarios
The primary application is automotive lighting. This includes: Exterior Signaling: Center High-Mount Stop Lights (CHMSL), rear combination lamps (stop/tail/turn), side marker lights. Interior LightingDashboard backlighting, switch illumination, ambient lighting. Advanced Driver Assistance Systems (ADAS)Sensor illumination where specific wavelength is required. Its AEC-Q102 qualification, wide temperature range, and sulfur resistance make it suitable for these harsh environments.
8.2 Design Considerations
Thermal Management: The most critical aspect. Use the thermal resistance (Rth JS real = 18 K/W) to calculate the junction temperature rise above the PCB temperature. Ensure adequate copper area (thermal pad) on the PCB, possibly with thermal vias to inner layers or a backside plane, to keep the solder pad temperature low. Refer to the derating curve. Current Drive: Use a constant-current driver for stable light output, especially over temperature. If using a series resistor, account for the forward voltage bin spread and supply voltage tolerance. Optics: The 120° viewing angle may require secondary optics (lenses, light guides) to shape the beam for specific applications. ESD Protection: Implement standard ESD precautions during handling and assembly. In the circuit, consider transient voltage suppression if the LED is connected to long wires or noisy automotive buses.
9. Technical Comparison and Differentiation
While a direct competitor comparison is not in the datasheet, key differentiators of this series can be inferred: Automotive Qualification: AEC-Q102 compliance is a significant differentiator from commercial-grade LEDs, involving rigorous stress tests for temperature cycling, humidity, high-temperature operating life, etc. Sulfur Resistance: Class A1 sulfur test criteria is crucial for automotive and industrial applications where atmospheric sulfur can corrode silver-based components. Halogen-Free: Meets environmental and safety standards required by many OEMs. Thermal Performance: The specified thermal resistance values allow for more accurate thermal modeling compared to parts that only provide a maximum power rating.
10. Frequently Asked Questions (Based on Technical Parameters)
Q: Nini ne haske na iya tsammani a zahiri?
A: Ƙimar al'ada ita ce 27 lm a 200mA. Duk da haka, dole ne ka ƙirƙira bisa mafi ƙarancin bin da kake son karɓa (misali, 20 lm don E8 bin) don tabbatar da aikin tsarin. Tuntuɓi mai kayan don takamaiman wadatar bin.
Q: Shin zan iya tuƙa wannan LED da PWM don dushewa?
A: Ehe, LEDs e mfumo wa PWM dimming. Hlola ukuthi i-peak current ngesikhathi se-"on" pulse ayidlu amanani avela kugrafu ethi "Permissible Pulse Handling Capability" nge-frequency yakho ekhethiwe kanye ne-duty cycle. I-frequency engaphezu kuka-100Hz iyacomsa ukuze ugweme ukucwayiza okubonakalayo.
Q: Ngingakubala kanjani i-heatsink edingekayo?
A: 1) Determine your operating current (e.g., 200mA) and corresponding VF (e.g., 2.3V). Power = 0.2A * 2.3V = 0.46W. 2) Estimate or measure the expected PCB temperature (Ts) at the solder pad. 3) Use Rth JS real (18 K/W): ΔT_junction = Power * Rth = 0.46W * 18 K/W ≈ 8.3K. 4) Junction Temp Tj = Ts + ΔT_junction. Ensure Tj < 150°C and preferably < 100°C for long life. Use the derating curve to check if your current is safe at your estimated Ts.
Q: Ingabe i-current-limiting resistor iyanele?
A: For simple, non-critical applications with a stable supply voltage (Vcc), a resistor can be used: R = (Vcc - VF_led) / I_F. Choose VF from the maximum bin (2.75V) to ensure current doesn't exceed limits if you get a low-VF LED. This method is inefficient and brightness will vary with Vcc and LED VF. A constant-current driver is recommended for automotive applications.
11. Design and Usage Case Study
Scenario: Designing a CHMSL (Center High-Mount Stop Light)
A designer needs 15 LEDs for a CHMSL. Requirements: High brightness for daytime visibility, consistent color, reliable operation from -40°C to +85°C ambient.
Design Steps: 1) Electrical: Choose a series configuration (all 15 LEDs in one string) to ensure identical current. A boost constant-current driver is selected to provide ~35V (15 * 2.3V) at 200mA. 2) OpticalSpecify a tight dominant wavelength bin (e.g., 3033 or 3336) and a minimum luminous flux bin (F1 for highest output) to ensure color and brightness uniformity. 3) ThermalThe PCB is a 2-layer board with the top layer dedicated to large copper fills under each LED's thermal pad, connected with thick traces. Thermal vias connect to a bottom-layer copper plane. Thermal simulation is run to ensure the solder pad temperature stays below 80°C at maximum ambient temperature, keeping the junction temperature well within limits. 4) Layout: The recommended solder pad layout is used. ESD protection diodes are placed on the input power lines.
12. Operational Principle Introduction
Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type region recombine with holes from the p-type region in the active layer. This recombination releases energy in the form of photons (light). The wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor materials used. For this Super Red LED, materials like AlInGaP (Aluminum Indium Gallium Phosphide) are typically used to achieve the 632 nm wavelength. The SMD package encapsulates the tiny semiconductor chip, provides mechanical protection, houses the primary lens that shapes the light output, and offers thermal and electrical connection paths via the lead frame.
13. Mienendo ya Teknolojia na Muktadha
Kifurushi cha 2820 kinawakilisha umbo la kukomaa na linalokubalika sana katika tasnia, likitoa usuluhishi mzuri kati ya pato la mwanga, utendaji wa joto, na nafasi ya bodi. Mienendo katika taa za LED za magari ni pamoja na: Ufanisi UlioongezekaOngoing development aims for higher lumens per watt (efficacy), reducing electrical load and thermal challenges. MiniaturizationSmart LightingIntegration of control electronics or multiple color chips (RGB) into packages is growing. Higher Reliability Standards: Automotive standards like AEC-Q102 continue to evolve, pushing for longer lifetime predictions and robustness under more extreme conditions. This particular component, with its clear automotive focus and sulfur resistance, aligns with the industry's demand for components that can survive the increasingly harsh and long-life requirements of modern vehicles.
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), misal, 120° | Kwanar da ƙarfin haske ya ragu zuwa rabi, yana ƙayyade faɗin katako. | Yana shafar kewayon haskakawa da daidaito. |
| 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) | Halin zazzabi na aiki a cikin LED chip. | Kowane raguwar 10°C na iya ninka tsawon rayuwa; yawan zafi yana haifar da raguwar haske, canjin launi. |
| 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. | Yana shafar daidaiton launi a cikin yanayin haske. |
| 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. |
| Ruwan tabarau/Na'urar gani | Lebur, Ƙananan ruwan tabarau, 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. |