Dual Color SMD LED Datasheet - Package 3.2x2.8x1.9mm - Voltage 2.0V - Power 75mW - Green/Yellow - English Technical Document

1. Product Overview

This document details the specifications for a compact, surface-mount dual-color LED lamp. The device is designed for automated printed circuit board (PCB) assembly processes and is suitable for applications where space is a critical constraint. It incorporates two distinct LED chips within a single package, enabling multi-status indication or color mixing in a minimal footprint.

1.1 Core Features and Target Market

The primary advantages of this component include its compliance with RoHS directives, utilization of high-brightness AlInGaP semiconductor technology, and packaging compatible with standard tape-and-reel formats for high-volume assembly. Its design is compatible with infrared (IR) reflow soldering processes. Target applications span a wide range of consumer and industrial electronics, including but not limited to telecommunications equipment (e.g., mobile phones), portable computing devices (e.g., notebooks), network hardware, home appliances, indoor signage, keyboard backlighting, and status indicator functions.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

Operating the device beyond these limits may cause permanent damage. Key ratings include a maximum power dissipation of 75 mW per color chip, a continuous DC forward current of 30 mA, and a peak forward current of 80 mA under pulsed conditions (1/10 duty cycle, 0.1ms pulse width). The maximum allowable reverse voltage is 5 V. The device is rated for an operating temperature range of -30°C to +85°C and a storage temperature range of -40°C to +85°C.

2.2 Electro-Optical Characteristics

Measured at a standard test current of 20 mA and an ambient temperature of 25°C, the typical forward voltage (Vf) for both the green and yellow chips is 2.0 V, with a specified range from 1.5 V (Min) to 2.4 V (Max). The luminous intensity (Iv) is a key performance metric. For the green chip, the typical value is 35.0 mcd (millicandela), with a minimum of 18.0 mcd. The yellow chip exhibits higher typical output at 75.0 mcd, with a minimum of 28.0 mcd. The viewing angle (2θ1/2), defined as the full angle at which intensity drops to half its axial value, is typically 130 degrees, indicating a wide viewing pattern. The dominant wavelength (λd) defines the perceived color. For green, it typically centers at 571 nm (range 564-578 nm), and for yellow, at 589 nm (range 582-596 nm). The spectral line half-width (Δλ) is typically 15.0 nm for both colors.

3. Bin Ranking System Explanation

The product is classified according to performance bins to ensure consistency in application. Two primary binning parameters are used: Luminous Intensity (Iv) and Dominant Wavelength (Hue).

3.1 Luminous Intensity Binning

The green LED is available in intensity bins M (18.0-28.0 mcd), N (28.0-45.0 mcd), and P (45.0-71.0 mcd). The yellow LED offers bins N (28.0-45.0 mcd), P (45.0-71.0 mcd), Q (71.0-112.0 mcd), and R (112.0-180.0 mcd). A tolerance of +/-15% is applied within each bin.

3.2 Hue (Wavelength) Binning

For the green LED, dominant wavelength is binned as C (567.5-570.5 nm), D (570.5-573.5 nm), and E (573.5-576.5 nm), with a tolerance of +/-1 nm per bin. This precise control ensures color consistency across production batches, which is critical for applications requiring uniform appearance.

4. Performance Curve Analysis

While specific graphical data is referenced in the source document (e.g., Figure 1 for spectral emission, Figure 5 for viewing angle), typical curves for such devices illustrate important relationships. The Forward Current vs. Forward Voltage (I-V) curve shows the exponential relationship characteristic of diodes. The Luminous Intensity vs. Forward Current curve typically shows a near-linear increase in light output with current up to a point, after which efficiency may drop. The spectral distribution curve would show a single peak for each monochromatic chip, with the half-width defining color purity. Understanding these curves is essential for circuit design, particularly for driving the LED at optimal efficiency and predicting light output under different operating conditions.

5. Mechanical and Package Information

5.1 Package Dimensions and Pin Assignment

The device features a standard SMD footprint. Critical dimensions include a body size of approximately 3.2 mm in length and 2.8 mm in width, with a typical height of 1.9 mm. Tolerances are typically ±0.1 mm. The package utilizes a water-clear lens. The pin assignment is as follows: Pins 1 and 3 are assigned to the green AlInGaP chip, while pins 2 and 4 are assigned to the yellow AlInGaP chip. This configuration allows for independent control of each color.

5.2 Recommended PCB Attachment Pad Layout

A recommended land pattern (footprint) is provided to ensure reliable soldering and proper mechanical alignment. This pattern typically includes pads slightly larger than the device's terminals to facilitate good solder fillet formation, which is critical for joint strength and thermal dissipation.

6. Soldering and Assembly Guidelines

6.1 IR Reflow Soldering Parameters

For lead-free (Pb-free) assembly processes, a specific reflow profile is recommended. The peak body temperature should not exceed 260°C, and the time above 260°C should be limited to a maximum of 10 seconds. A pre-heat stage up to 200°C is advised. The profile should be characterized for the specific PCB design, solder paste, and oven used. The device is qualified for a maximum of two reflow cycles under these conditions.

6.2 Manual Soldering

If manual soldering with an iron is necessary, the tip temperature should be controlled to a maximum of 300°C, and the soldering time per lead should not exceed 3 seconds. Manual soldering should be performed only once.

6.3 Storage and Handling

The LEDs are moisture-sensitive (MSL 3). When stored in their original sealed moisture-barrier bag with desiccant, they should be kept at ≤30°C and ≤90% RH and used within one year. Once the bag is opened, the components should be stored at ≤30°C and ≤60% RH. It is recommended to complete the IR reflow process within one week of opening the bag. For components stored out of the original packaging for more than a week, a baking procedure (e.g., 60°C for at least 20 hours) is required before soldering to remove absorbed moisture and prevent \"popcorning\" damage during reflow.

6.4 Cleaning

If cleaning after soldering is required, only specified solvents should be used. Immersing the LED in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute is acceptable. Unspecified chemicals may damage the package material.

7. Packaging and Ordering Information

The components are supplied on 8 mm wide embossed carrier tape wound onto 7-inch (178 mm) diameter reels, in accordance with EIA-481 standards. Each reel contains 3000 pieces. The tape utilizes a cover tape to seal the component pockets. For quantities less than a full reel, a minimum packing quantity of 500 pieces applies for remainder lots.

8. Application Suggestions

8.1 Typical Application Scenarios

This dual-color LED is ideal for multi-state indication. For example, in a network router, the green chip could indicate \"power on/operation normal,\" while the yellow chip could indicate \"data activity\" or \"system alert.\" In consumer electronics, it can serve as a combined charging/status indicator. Its small size makes it suitable for backlighting miniature keypads or icons on handheld devices.

8.2 Design Considerations

Current Limiting: Always use a series current-limiting resistor for each LED chip. The resistor value can be calculated using Ohm's Law: R = (Vsupply - Vf_LED) / I_desired. Using the typical Vf of 2.0V and a desired current of 20 mA with a 5V supply, R = (5V - 2.0V) / 0.020A = 150 Ω.
Thermal Management: While the power dissipation is low, ensuring adequate PCB copper around the thermal pads (if any) or leads helps dissipate heat, especially in high ambient temperature environments, maintaining LED longevity and stable light output.
ESD Protection: The device is sensitive to electrostatic discharge (ESD). Proper ESD controls (wrist straps, grounded workstations, conductive foam) must be employed during handling and assembly.

9. Technical Comparison and Differentiation

Compared to single-color SMD LEDs, this device offers space savings by combining two functions in one package, reducing PCB real estate and assembly time. The use of AlInGaP technology typically offers higher luminous efficiency and better temperature stability compared to some other LED technologies for these specific colors (green and yellow), resulting in brighter and more consistent output over the operating temperature range.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive both the green and yellow LEDs simultaneously at their maximum DC current (30 mA each)?
A: Technically yes, but you must consider the total power dissipation. Simultaneous operation at 30mA each would result in a combined power dissipation that may exceed the recommended limits if the forward voltages are at the higher end of their range. It is safer to operate below the absolute maximum ratings, perhaps at 20 mA each, and ensure adequate thermal design.

Q: What is the difference between peak wavelength and dominant wavelength?
A: Peak wavelength (λp) is the wavelength at which the spectral power distribution is maximum. Dominant wavelength (λd) is the single wavelength of monochromatic light that matches the perceived color of the LED when compared to a reference white light. λd is more relevant for color specification in human-centric applications.

Q: Why is the storage condition after opening the bag so important?
A> SMD packages can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, creating internal pressure that can delaminate the package or crack the die, a failure known as \"popcorning.\" The specified storage conditions and baking procedures prevent this.

11. Practical Application Case

Scenario: Designing a Dual-Status Indicator for a Portable Device
A designer is creating a compact media player with a single indicator LED. The requirements are: solid green for \"play,\" blinking green for \"pause,\" and solid yellow for \"charging/standby.\" Using this dual-color LED simplifies the design. A microcontroller with two GPIO pins can independently control the green and yellow chips via simple transistor switches or directly if the GPIO can sink/sufficient current. The wide 130-degree viewing angle ensures the status is visible from various angles. The designer selects components from the same intensity and hue bin to guarantee uniform color and brightness across all production units.

12. Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light when an electric current passes through them. This phenomenon is called electroluminescence. In an AlInGaP (Aluminum Indium Gallium Phosphide) LED, electrical energy causes electrons and holes to recombine within the semiconductor's active region, releasing energy in the form of photons (light). The specific color of the light is determined by the bandgap energy of the semiconductor material, which is engineered by adjusting the ratios of the constituent elements. A dual-color LED package houses two such semiconductor chips with different bandgaps, electrically isolated but sharing a common mechanical structure.

13. Development Trends

The general trend in SMD LED technology continues toward higher efficiency (more lumens per watt), enabling brighter displays or lower power consumption. Miniaturization remains a key driver, allowing for denser packaging and new form factors in consumer electronics. There is also a focus on improved color rendering and consistency, as well as enhanced reliability under harsh environmental conditions. Integration, such as combining control ICs with LEDs in a single package (\"smart LEDs\"), is another growing area to simplify system design.