Dual Color SMD LED Datasheet - AlInGaP Chip - Green & Red - 30mA - English Technical Document

1. Product Overview

This document details the technical specifications for a high-brightness, dual-color Surface Mount Device (SMD) LED. The device incorporates two independent semiconductor chips within a single package: one emitting green light and the other emitting red light. Utilizing advanced Aluminium Indium Gallium Phosphide (AlInGaP) chip technology, this LED is designed for applications requiring two distinct color indicators from a compact, single-component footprint. Its primary advantages include high luminous intensity, compatibility with automated assembly processes, and adherence to environmental standards.

The LED is packaged on industry-standard 8mm tape, supplied on 7-inch reels, making it suitable for high-volume, automated pick-and-place manufacturing lines. It is compatible with various soldering processes, including infrared and vapor phase reflow, and is classified as a green product, meeting relevant environmental directives.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

The device's operational limits are defined under an ambient temperature (Ta) of 25°C. Both the green and red chips share identical maximum ratings, ensuring symmetrical performance and design safety margins.

• Power Dissipation: 75 mW per chip. This parameter defines the maximum power the LED can safely dissipate as heat under continuous operation.
• Peak Forward Current: 80 mA, permissible under pulsed conditions (1/10 duty cycle, 0.1ms pulse width). This rating is crucial for multiplexing or brief high-intensity signaling applications.
• DC Forward Current: 30 mA. This is the recommended maximum continuous forward current for reliable, long-term operation.
• Current Derating: Linear derating of 0.4 mA/°C from 25°C. For every degree Celsius above 25°C, the maximum allowable continuous current must be reduced by 0.4 mA to prevent thermal overstress.
• Reverse Voltage: 5 V. Exceeding this voltage in the reverse direction can cause immediate and irreversible damage to the LED chip.
• Temperature Range: Operating and storage temperature range is -55°C to +85°C, indicating suitability for industrial and extended environmental applications.
• Soldering Tolerance: The device can withstand wave or infrared soldering at 260°C for 5 seconds, and vapor phase soldering at 215°C for 3 minutes.

2.2 Electrical & Optical Characteristics

Measured at Ta=25°C and a standard test current (IF) of 2 mA, these parameters define the core performance of the LED.

• Luminous Intensity (Iv): Minimum 1.8 mcd, typical 2.5 mcd for both colors. This is the perceived brightness of the light output as measured by a sensor filtered to the CIE photopic (human eye) response curve.
• Viewing Angle (2θ1/2): Typically 130 degrees. This wide viewing angle indicates a diffuse, non-focused emission pattern suitable for status indicators that need to be visible from a broad range of perspectives.
• Peak Wavelength (λP): Green: 570 nm (Typical). Red: 636 nm (Typical). This is the wavelength at which the spectral power output is maximum.
• Dominant Wavelength (λd): Green: 569 nm (Typical). Red: 633 nm (Typical). This is the single wavelength that best represents the perceived color of the LED, derived from the CIE chromaticity diagram.
• Spectral Bandwidth (Δλ): Green: 15 nm (Typical). Red: 20 nm (Typical). This defines the spectral purity; a narrower bandwidth indicates a more saturated, pure color.
• Forward Voltage (VF): Green: 1.8V (Typical), 2.2V (Max). Red: 1.7V (Typical), 2.2V (Max). The voltage drop across the LED when conducting the specified current. This is critical for circuit design and power supply selection.
• Reverse Current (IR): Maximum 10 μA at VR=5V. A measure of the junction's leakage in the off-state.
• Capacitance (C): Typically 40 pF at VF=0V, f=1MHz. Relevant for high-frequency switching applications.

3. Binning System Explanation

The LEDs are sorted into performance bins to ensure consistency within a production batch. Designers can specify bins to meet precise application requirements.

3.1 Luminous Intensity Binning

Both green and red chips use the same intensity bin codes. The tolerance within each bin is +/-15%.

• Bin Code G: 1.80 mcd (Min) to 2.80 mcd (Max) @ 2mA.
• Bin Code H: 2.80 mcd (Min) to 4.50 mcd (Max) @ 2mA.
• Bin Code J: 4.50 mcd (Min) to 7.10 mcd (Max) @ 2mA.

3.2 Dominant Wavelength Binning (Green Only)

Only the green chip has specified wavelength bins to control color consistency. The tolerance for each bin is +/- 1nm.

• Bin Code C: 567.5 nm to 570.5 nm.
• Bin Code D: 570.5 nm to 573.5 nm.
• Bin Code E: 573.5 nm to 576.5 nm.

4. Performance Curve Analysis

While specific graphical curves are referenced in the datasheet (e.g., Fig.1, Fig.6), their typical characteristics can be described based on the technology and specified parameters.

Forward Current vs. Forward Voltage (I-V Curve): AlInGaP LEDs exhibit a characteristic exponential I-V relationship. The typical VF values of ~1.8V indicate a relatively low operating voltage compared to some other semiconductor materials. The curve will show a sharp turn-on at the threshold voltage, followed by a region where voltage increases approximately linearly with current.

Luminous Intensity vs. Forward Current (L-I Curve): The light output is generally linear with current in the recommended operating range (up to 30mA DC). However, at higher currents, efficiency may drop due to thermal effects and other non-linearities within the semiconductor.

Temperature Dependence: The luminous intensity of LEDs typically decreases with increasing junction temperature. The specified current derating factor (0.4 mA/°C) is a direct consequence of this thermal behavior, implemented to maintain reliability. The forward voltage also has a negative temperature coefficient, meaning it decreases slightly as temperature rises.

Spectral Distribution: The green chip, with a typical peak at 570 nm and a narrow 15 nm bandwidth, will produce a saturated green light. The red chip, peaking at 636 nm with a 20 nm bandwidth, produces a standard red color. These wavelengths are well within the high-sensitivity regions of the human eye.

5. Mechanical & Packaging Information

5.1 Device Dimensions and Pin Assignment

The LED conforms to an EIA standard SMD package footprint. The lens is water clear. The internal pin assignment for the dual chips is as follows:

• Green Chip: Connected to pins 1 and 3.
• Red Chip: Connected to pins 2 and 4.

This configuration allows the two LEDs to be driven completely independently. All dimensional tolerances are ±0.10 mm unless otherwise specified.

5.2 Suggested Soldering Pad Layout

A recommended land pattern (solder pad dimensions) is provided to ensure proper solder joint formation, mechanical stability, and thermal relief during the reflow process. Adhering to this layout is critical for achieving reliable surface mount connections and preventing tombstoning or misalignment.

5.3 Tape and Reel Packaging

The device is supplied in an 8mm wide embossed carrier tape. Key packaging specifications include:

• Reel Size: 7 inches in diameter.
• Quantity per Reel: 3000 pieces.
• Minimum Order Quantity (MOQ): 500 pieces for remainder quantities.
• Cover Tape: Empty component pockets are sealed with a top cover tape.
• Missing Components: A maximum of two consecutive missing LEDs is allowed per the packaging standard.
• Standard: Packaging conforms to ANSI/EIA 481-1-A-1994 specifications.

6. Soldering & Assembly Guidelines

6.1 Recommended Reflow Profiles

Two suggested infrared (IR) reflow soldering profiles are provided: one for standard (tin-lead) solder process and one for lead-free (Pb-free) solder process. The lead-free profile is specifically designed for use with Sn-Ag-Cu (SAC) alloy solder pastes. Both profiles define critical parameters like pre-heat temperature and time, peak temperature, and time above liquidus to ensure proper solder joint formation without subjecting the LED package to excessive thermal stress.

6.2 General Soldering Conditions

• Reflow Soldering: Pre-heat: 120-150°C for max 120 sec. Peak temperature: 240°C max. Time above liquidus: 10 sec max.
• Wave Soldering: Pre-heat: 100°C max for 60 sec max. Solder wave: 260°C max for 10 sec max.
• Hand Soldering (Iron): Temperature: 300°C max. Soldering time: 3 seconds max per joint (one time only).

6.3 Cleaning

If cleaning is necessary after soldering, only specified chemical agents should be used. Unspecified chemicals may damage the LED package material. It is recommended to immerse the LED in ethyl alcohol or isopropyl alcohol at normal room temperature for less than one minute.

6.4 Storage and Handling

• Storage Environment: Should not exceed 30°C and 70% relative humidity.
• Moisture Sensitivity: LEDs removed from their original, moisture-barrier packaging should be reflow-soldered within one week. For longer storage outside the original bag, they must be stored in a sealed container with desiccant or in a nitrogen desiccator.
• Baking: Components stored out of bag for more than a week require baking at approximately 60°C for at least 24 hours prior to assembly to remove absorbed moisture and prevent "popcorning" during reflow.

7. Application Recommendations

7.1 Typical Application Scenarios

This dual-color LED is ideal for applications requiring multi-status indication from a single point, such as:

• Status Indicators: Power (Green=On, Red=Off/Error), network activity, battery charging status (Red=Charging, Green=Full).
• Consumer Electronics: Indicators on appliances, audio/video equipment, and computer peripherals.
• Industrial Control Panels: Machine state indication (Green=Running, Red=Stopped/Fault).
• Automotive Interior Lighting: Dual-function dashboard or console indicators.

7.2 Circuit Design Considerations

Drive Method: LEDs are current-driven devices. To ensure uniform brightness, especially when multiple LEDs are used in parallel, it is strongly recommended to use a series current-limiting resistor for each LED (Circuit Model A). Driving multiple LEDs in parallel directly from a voltage source (Circuit Model B) is not recommended, as slight variations in the forward voltage (VF) characteristic between individual LEDs will cause significant differences in current share and, consequently, brightness.

The value of the series resistor (R_s) can be calculated using Ohm's Law: R_s = (V_supply - V_F) / I_F, where V_F is the forward voltage of the LED at the desired current I_F.

7.3 Electrostatic Discharge (ESD) Protection

The LED is sensitive to electrostatic discharge, which can degrade or destroy the semiconductor junction. Precautions must be taken during handling and assembly:

• Personnel should wear grounded wrist straps or anti-static gloves.
• All workstations, tools, and equipment must be properly grounded.
• Use conductive or dissipative mats on work surfaces.
• Store and transport LEDs in ESD-protective packaging.

8. Technical Comparison & Differentiation

The key differentiating features of this product are its dual-color capability in a single SMD package and the use of AlInGaP chip technology.

Compared to single-color LEDs, this device saves PCB space, reduces component count, and simplifies assembly for applications needing two colors. Compared to other dual-color technologies (e.g., a single chip with a phosphor), the use of two discrete AlInGaP chips offers advantages:

• Color Saturation: AlInGaP provides highly saturated, pure green and red colors without the need for phosphor conversion, resulting in higher color purity.
• Efficiency: AlInGaP is known for high external quantum efficiency, especially in the red and amber regions, contributing to the device's high brightness.
• Independent Control: The two chips are electrically isolated, allowing completely independent control of color, brightness, and blinking patterns.

9. Frequently Asked Questions (FAQs)

Q1: Can I drive both the green and red LEDs simultaneously at their maximum DC current (30mA each)?

A1: Yes, but you must consider the total power dissipation. At 30mA, with typical VF of 1.8V (Green) and 1.7V (Red), the total power would be approximately (0.03A * 1.8V) + (0.03A * 1.7V) = 0.105W or 105 mW. This exceeds the individual chip rating of 75 mW. Therefore, simultaneous operation at full current may require thermal management or derating based on the ambient temperature and PCB layout to ensure the junction temperature remains within safe limits.

Q2: What is the difference between Peak Wavelength and Dominant Wavelength?

A2: Peak Wavelength (λP) is the physical wavelength where the LED emits the most optical power. Dominant Wavelength (λd) is a calculated value based on the CIE color chart that represents the perceived color as a single wavelength. For a monochromatic source like an AlInGaP LED, they are often very close, but λd is the more relevant parameter for color specification in applications.

Q3: How do I interpret the binning codes when ordering?

A3: You can specify the desired intensity bin (e.g., "J" for highest brightness) and, for the green chip, the dominant wavelength bin (e.g., "D" for a specific green hue). This ensures you receive LEDs with consistent performance. If not specified, you may receive a mix from production.

Q4: Is a heat sink necessary?

A4: For continuous operation at or near the maximum DC current, especially in high ambient temperatures or when both colors are on, careful thermal design is important. While a dedicated heat sink may not be needed for a single indicator, ensuring a good thermal path from the LED pads to the PCB copper (using thermal vias or large copper pours) is recommended to help dissipate heat and maintain performance and longevity.

10. Design and Usage Case Study

Scenario: Designing a Dual-Status Power Indicator for a Portable Device

Requirements: Indicate "Charging" (Red) and "Fully Charged/On" (Green). The device is powered by a 5V USB source. The indicator should be clearly visible but not overly bright to conserve power.

Design Steps:

1. Current Selection: Choose a forward current (I_F) that provides adequate brightness. From the typical Luminous Intensity of 2.5 mcd at 2 mA, 5 mA might be a good starting point for a clear indicator.
2. Resistor Calculation:
   
   For the Red LED (V_F typ = 1.7V) at 5 mA:
   
   R_Red = (5V - 1.7V) / 0.005A = 660 Ω. Use a standard 680 Ω resistor.
   
   For the Green LED (V_F typ = 1.8V) at 5 mA:
   
   R_Green = (5V - 1.8V) / 0.005A = 640 Ω. Use a standard 620 Ω or 680 Ω resistor.
3. Power Check: Power per LED: P = V_F * I_F ≈ 1.7V * 0.005A = 8.5 mW (Red) and 1.8V * 0.005A = 9 mW (Green). Both are well below the 75 mW maximum, even if both were on simultaneously (which they won't be in this use case).
4. Circuit Implementation: Connect the red LED (pins 2,4) with its 680Ω resistor to a microcontroller GPIO pin set to output high during charging. Connect the green LED (pins 1,3) with its resistor to a different GPIO pin, activated when charging is complete or the device is on. The common cathode/anode configuration (implied by independent pins) allows this simple independent drive.
5. PCB Layout: Follow the suggested solder pad dimensions. Ensure no solder mask is present between the pads to prevent solder bridging. Include a small copper pour connected to the ground plane under the LED for slight thermal relief.

11. Technology Principle Introduction

This LED is based on Aluminium Indium Gallium Phosphide (AlInGaP) semiconductor material. This is a III-V compound semiconductor where the bandgap energy--the energy difference between the valence band and conduction band--can be precisely tuned by varying the ratios of Al, In, Ga, and P. This tunability allows engineers to design materials that emit light at specific wavelengths across the red, orange, amber, and green regions of the visible spectrum.

When a forward voltage is applied across the p-n junction of the AlInGaP chip, electrons are injected from the n-region into the p-region, and holes from the p-region into the n-region. These charge carriers recombine in the active region of the junction. In a direct bandgap semiconductor like AlInGaP, this recombination event releases energy in the form of a photon (light particle). The wavelength (color) of this photon is directly determined by the bandgap energy of the material (E_photon = hc/λ ≈ E_bandgap). The dual-color package houses two such independently fabricated chips, each made from AlInGaP material with a different composition to produce green and red light, respectively.

12. Industry Trends and Developments

The market for SMD indicator LEDs continues to evolve. Key trends relevant to this type of component include:

• Miniaturization: While this device uses a standard package, there is a constant push for smaller footprints (e.g., 0402, 0201) to save space on increasingly dense PCBs, especially in consumer portable electronics.
• Increased Efficiency: Ongoing material science and chip design improvements aim to extract more light (lumens) per electrical watt input, reducing power consumption for a given brightness level.
• Enhanced Reliability and Robustness: Improvements in packaging materials and die attach technologies enhance the device's ability to withstand higher temperatures, humidity, and mechanical stress, expanding its use in automotive and industrial applications.
• Integrated Solutions: A trend towards integrating the LED driver circuitry (constant current source, PWM controller) either within the LED package itself or in closely associated ICs to simplify end-user design and improve performance consistency.
• Color and Brightness Consistency: Advances in epitaxial growth and binning processes continue to tighten the tolerances on parameters like dominant wavelength and luminous intensity, providing designers with more predictable and uniform results across large production runs.