Dual Color AlInGaP SMD LED Datasheet - Green & Orange - 5mA - 75mW - English Technical Document

1. Product Overview

This document details the specifications for a high-brightness, dual-color Surface Mount Device (SMD) LED. The device incorporates two distinct AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor chips within a single package, enabling the emission of green and orange light. Designed for automated assembly processes, it is packaged on 8mm tape supplied on 7-inch reels, making it suitable for high-volume manufacturing. The product is compliant with RoHS directives and is classified as a green product.

The core advantage of this LED lies in its use of AlInGaP technology, which is known for producing high luminous efficiency and excellent color purity compared to traditional LED materials. The dual-color capability in a single, compact EIA-standard package allows for space-saving designs in applications requiring multiple indicator colors or simple bi-color status displays.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are specified at an ambient temperature (Ta) of 25°C. For both the green and orange chips, the maximum continuous DC forward current is 30 mA. The power dissipation for each chip is limited to 75 mW. A derating factor of 0.4 mA/°C applies linearly from 25°C, meaning the allowable forward current decreases as the ambient temperature rises to prevent overheating. The device can withstand a reverse voltage of up to 5 V. The operating temperature range is from -30°C to +85°C, and it can be stored in environments from -40°C to +85°C. The infrared soldering condition is specified as 260°C for a maximum of 5 seconds.

2.2 Electrical & Optical Characteristics

These parameters are measured under standard test conditions (Ta=25°C, IF=5mA) and define the typical performance of the device.

• Luminous Intensity (Iv): For the green chip, the minimum intensity is 4.5 mcd, typical is unspecified, and maximum is 28.0 mcd. For the orange chip, the minimum is 11.2 mcd, typical is unspecified, and maximum is 71.0 mcd. Intensity is measured using a sensor filtered to match the CIE photopic eye-response curve.
• Viewing Angle (2θ1/2): Both colors have a typical viewing angle of 130 degrees. This is the full angle at which the luminous intensity drops to half of its peak axial value.
• Wavelength: The green chip has a typical peak emission wavelength (λP) of 574 nm and a typical dominant wavelength (λd) of 571 nm. The orange chip has a typical λP of 611 nm and a typical λd of 605 nm. The dominant wavelength is the single wavelength perceived by the human eye that defines the color.
• Spectral Line Half-Width (Δλ): The green chip has a typical value of 15 nm, and the orange chip 17 nm. This indicates the spectral purity or bandwidth of the emitted light.
• Forward Voltage (VF): Both chips have a typical forward voltage of 1.9 V and a maximum of 2.3 V when driven at 5 mA.
• Reverse Current (IR): The maximum reverse current for both chips is 10 µA when a reverse voltage of 5 V is applied.

3. Binning System Explanation

The luminous intensity of the LEDs is sorted into bins to ensure consistency within a production lot. Each bin has a defined minimum and maximum intensity value, with a tolerance of +/-15% applied to each bin.

Green Color Bins:

- Bin J: 4.5 mcd (Min) to 7.1 mcd (Max)

- Bin K: 7.1 mcd to 11.2 mcd

- Bin L: 11.2 mcd to 18.0 mcd

- Bin M: 18.0 mcd to 28.0 mcd

Orange Color Bins:

- Bin L: 11.2 mcd to 18.0 mcd

- Bin M: 18.0 mcd to 28.0 mcd

- Bin N: 28.0 mcd to 45.0 mcd

- Bin P: 45.0 mcd to 71.0 mcd

This binning allows designers to select LEDs with predictable brightness levels for their application, crucial for achieving uniform appearance in multi-LED arrays or meeting specific brightness requirements.

4. Performance Curve Analysis

The datasheet references typical performance curves which are essential for understanding device behavior under non-standard conditions. While the specific graphs are not reproduced in the text, they typically include:

• Relative Luminous Intensity vs. Forward Current: Shows how light output increases with drive current, typically in a non-linear fashion, highlighting the point of diminishing returns or potential saturation.
• Forward Voltage vs. Forward Current: Illustrates the IV characteristic of the diode, crucial for designing appropriate current-limiting circuitry.
• Relative Luminous Intensity vs. Ambient Temperature: Demonstrates the thermal quenching effect, where light output decreases as the junction temperature rises. This is critical for applications in high-temperature environments.
• Spectral Distribution: A graph showing the relative power emitted across different wavelengths, centered around the peak wavelength, with the half-width clearly visible.

These curves allow engineers to predict performance in real-world scenarios, not just at the standard 25°C, 5mA test point.

5. Mechanical & Packaging Information

The device conforms to an EIA standard package outline. Detailed package dimension drawings are included in the datasheet, specifying all critical lengths, widths, heights, and lead spacings in millimeters. A suggested soldering pad layout (land pattern) is provided to ensure reliable solder joint formation and proper alignment during reflow. The pin assignment is clearly defined: Pins 1 and 3 are for the green chip, and pins 2 and 4 are for the orange chip. This information is vital for PCB layout designers to create correct footprints.

The LEDs are supplied in a tape-and-reel format compatible with automated pick-and-place machines. The tape width is 8mm, wound on a standard 7-inch diameter reel. Each reel contains 4000 pieces. Packaging specifications follow ANSI/EIA 481-1-A-1994 standards, with rules on minimum order quantity (500 pieces for remainders) and maximum consecutive missing components (two).

6. Soldering & Assembly Guide

6.1 Reflow Soldering Profiles

Two suggested infrared (IR) reflow profiles are provided: one for standard (tin-lead) solder process and one for lead-free (SnAgCu) solder process. The lead-free profile requires a higher peak temperature. The general recommendation is a pre-heat zone of 120-150°C, a pre-heat time under 120 seconds, a peak temperature not exceeding 260°C, and a time above that peak temperature limited to 5 seconds. These parameters are critical to prevent thermal damage to the LED's plastic package and internal wire bonds.

6.2 Storage & Handling

LEDs should be stored in an environment not exceeding 30°C and 70% relative humidity. Once removed from their original moisture-barrier packaging, they should undergo IR reflow soldering within one week. For longer storage outside the original bag, they must be kept in a sealed container with desiccant or in a nitrogen atmosphere. If stored unpackaged for more than a week, a bake-out at approximately 60°C for at least 24 hours is required before soldering to remove absorbed moisture and prevent \"popcorning\" during reflow.

6.3 Cleaning

Only specified cleaning agents should be used. Unspecified chemicals may damage the epoxy lens. If cleaning is necessary, immersion in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute is recommended.

7. Application Suggestions

7.1 Typical Application Scenarios

This dual-color LED is ideal for status indicators, backlighting for buttons or icons, and panel displays in consumer electronics, office equipment, communication devices, and household appliances. Its bi-color nature allows it to show two distinct states (e.g., power on/green, standby/orange; charge status; network activity) from a single component location, saving board space and cost.

7.2 Design Considerations

Drive Circuit: LEDs are current-driven devices. To ensure uniform brightness when multiple LEDs are connected in parallel, it is strongly recommended to use a series current-limiting resistor for each individual LED (Circuit Model A). Driving multiple LEDs in parallel directly from a voltage source with a single shared resistor (Circuit Model B) is discouraged, as slight variations in the forward voltage (VF) characteristic between individual LEDs will cause significant differences in current share and, consequently, brightness.

Electrostatic Discharge (ESD) Protection: The LED is sensitive to ESD. Preventive measures must be implemented during handling and assembly: use grounded wrist straps and workstations, employ ionizers to neutralize static charge on the lens, and store components in anti-static packaging. ESD damage often manifests as abnormally high reverse leakage current.

8. Technical Comparison & Differentiation

The key differentiator of this product is the use of AlInGaP semiconductor material for both colors. Compared to older technologies like standard GaP (Gallium Phosphide), AlInGaP offers significantly higher luminous efficiency, resulting in brighter output at the same drive current. The dual-chip-in-one-package design provides a compact alternative to using two separate single-color LEDs, reducing part count, assembly time, and PCB footprint. The wide 130-degree viewing angle makes it suitable for applications where the indicator needs to be visible from a broad range of perspectives.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED at 20mA continuously?

A: Yes. The maximum continuous DC forward current is 30 mA, so 20 mA is within the safe operating area. However, always refer to the derating curve if operating at high ambient temperatures.

Q: Why is a series resistor necessary for each LED in parallel?

A: The forward voltage (VF) of LEDs has a production tolerance. Without individual resistors, LEDs with a slightly lower VF will draw disproportionately more current, becoming brighter and potentially overheating, while those with a higher VF will be dim. The resistor acts as a simple current regulator for each LED.

Q: What does \"dominant wavelength\" mean versus \"peak wavelength\"?

A: Peak wavelength is the single wavelength where the emitted optical power is highest. Dominant wavelength is derived from the color coordinates on the CIE chromaticity diagram and represents the single wavelength that the human eye perceives as the color of the light. It is often the more relevant parameter for color specification.

Q: How do I interpret the bin code L for orange?

A: If you receive LEDs from bin L for the orange color, you can expect the luminous intensity of each LED, when measured at 5mA, to fall between 11.2 mcd and 18.0 mcd, with a +/-15% tolerance on those bin limits.

10. Practical Design Case Study

Scenario: Designing a status indicator for a network router that shows power (steady green) and data activity (blinking orange).

Implementation: A single LTST-C195KGKFKT-5A LED can be used. Pins 1/3 (green) are connected to a GPIO pin set to output a constant high logic level when power is on, through a suitable current-limiting resistor (e.g., calculated for ~5-10mA from a 3.3V supply: R = (3.3V - 1.9V) / 0.005A ≈ 280Ω). Pins 2/4 (orange) are connected to a different GPIO pin controlled by the network controller to blink in sync with data packets. The use of individual resistors for each color channel is essential. The wide viewing angle ensures the status is visible from anywhere in the room. The design saves one LED footprint compared to a two-LED solution.

11. Principle of Operation

An LED is a semiconductor diode. When a forward voltage exceeding its characteristic forward voltage (VF) is applied, electrons from the n-type semiconductor and holes from the p-type semiconductor are injected into the active region. When an electron recombines with a hole, energy is released in the form of a photon (light). The specific wavelength (color) of this light is determined by the energy bandgap of the semiconductor material. AlInGaP has a bandgap that produces light in the red, orange, amber, and green portions of the visible spectrum, depending on its exact composition. This device contains two separate AlInGaP chips with different compositions, grown to emit green and orange light, housed in a clear (water clear) epoxy lens that also acts as the primary optical element.

12. Technology Trends

The trend in indicator LEDs continues towards higher efficiency, smaller packages, and lower power consumption. AlInGaP technology represents a mature and efficient solution for red-to-green colors. Ongoing development focuses on improving the efficiency at higher drive currents and enhancing the color stability over temperature and lifetime. Integration, such as the dual-color chip in this datasheet, is a key trend to reduce system size and complexity. Furthermore, compatibility with lead-free, high-temperature reflow processes is now a standard requirement for all SMD components to meet global environmental regulations. Future developments may see further integration of control circuitry or multiple colors into ever-smaller package footprints.