SMD LED LTST-C930KAKT Datasheet - AlInGaP Red Orange - 30mA - 75mW - English Technical Document

1. Product Overview

This document provides the complete technical specifications for a high-brightness, surface-mount LED designed for automated assembly processes. The device utilizes advanced AlInGaP semiconductor technology to deliver a red-orange emission. It is engineered for reliability and performance in a wide range of modern electronic applications where space, efficiency, and consistent light output are critical.

1.1 Features

• Compliant with RoHS environmental directives.
• Incorporates a dome lens for optimized light distribution.
• Utilizes an ultra-bright AlInGaP chip for high luminous efficiency.
• Supplied in industry-standard 8mm tape on 7-inch reels for automated pick-and-place.
• Package conforms to EIA standards.
• Designed for compatibility with integrated circuits (I.C. compatible).
• Suitable for use with automatic placement equipment.
• Withstands infrared (IR) reflow soldering processes.

1.2 Applications

This LED is suitable for diverse applications including:

• Telecommunication equipment, office automation systems, home appliances, and industrial control panels.
• Backlighting for keypads and keyboards.
• Status and power indicators.
• Micro-displays and panel indicators.
• Signal and symbolic illumination.

2. Package Dimensions and Configuration

The device features a standard surface-mount package. Critical dimensions include length, width, and height, with a typical tolerance of ±0.1mm unless otherwise specified. The lens is water clear, and the light source color is AlInGaP Red Orange. Detailed mechanical drawings specifying all critical dimensions are an essential part of the design-in process for PCB layout.

3. Technical Parameters and Characteristics

All ratings and characteristics are defined at an ambient temperature (Ta) of 25°C unless stated otherwise.

3.1 Absolute Maximum Ratings

Stresses beyond these limits may cause permanent damage to the device.

• Power Dissipation: 75 mW
• Peak Forward Current (1/10 Duty Cycle, 0.1ms pulse): 80 mA
• Continuous DC Forward Current: 30 mA
• Reverse Voltage: 5 V
• Operating Temperature Range: -30°C to +85°C
• Storage Temperature Range: -40°C to +85°C
• Infrared Soldering Condition: 260°C for 10 seconds maximum.

3.2 Suggested IR Reflow Profile

For lead-free (Pb-free) soldering processes, a reflow profile with a peak temperature of 260°C for a maximum of 10 seconds is recommended. The profile should include appropriate pre-heating and cooling stages to minimize thermal stress on the component and the printed circuit board.

3.3 Electrical and Optical Characteristics

Typical performance parameters measured under standard test conditions (IF=20mA).

• Luminous Intensity (Iv): 300 mcd (Min), 1050 mcd (Typ)
• Viewing Angle (2θ1/2): 25 degrees
• Peak Emission Wavelength (λP): 621 nm (Typical)
• Dominant Wavelength (λd): 615 nm (Typical)
• Spectral Line Half-Width (Δλ): 18 nm (Typical)
• Forward Voltage (VF): 2.0 V (Typ), 2.4 V (Max)
• Reverse Current (IR): 10 μA (Max) at VR=5V

Measurement Notes: Luminous intensity is measured using a sensor-filter combination approximating the CIE photopic eye-response curve. The viewing angle is defined as the off-axis angle where intensity drops to half its axial value. Dominant wavelength is derived from CIE chromaticity coordinates.

3.4 Electrostatic Discharge (ESD) Caution

This device is sensitive to electrostatic discharge. Proper ESD handling procedures must be followed, including the use of grounded wrist straps, anti-static gloves, and ensuring all equipment and workstations are correctly grounded to prevent damage.

4. Bin Ranking System

To ensure color and brightness consistency in production, devices are sorted into bins based on luminous intensity.

4.1 Luminous Intensity Bin Codes

For the Red Orange color, measured at 20mA. Tolerance within each bin is +/-15%.

• R: 112.0 - 180.0 mcd
• S: 180.0 - 280.0 mcd
• T: 280.0 - 450.0 mcd
• U: 450.0 - 710.0 mcd
• V: 710.0 - 1120.0 mcd
• W: 1120.0 - 1800.0 mcd
• X: 1800.0 - 2800.0 mcd
• Y: 2800.0 - 4500.0 mcd

This binning allows designers to select the appropriate brightness grade for their specific application, balancing cost and performance requirements.

5. Typical Performance Curves

Graphical data provides deeper insight into device behavior under varying conditions. Key curves typically include:

• Relative Luminous Intensity vs. Forward Current: Shows how light output increases with drive current, highlighting the non-linear relationship and the importance of current regulation.
• Relative Luminous Intensity vs. Ambient Temperature: Demonstrates the thermal derating of light output, which is crucial for designs operating in elevated temperature environments.
• Forward Voltage vs. Forward Current: Illustrates the diode's IV characteristic, essential for designing the current-limiting circuitry.
• Spectral Distribution: A plot of relative radiant power versus wavelength, showing the narrow emission band characteristic of AlInGaP LEDs centered around 621nm.

Analyzing these curves helps engineers predict real-world performance, manage thermal effects, and optimize drive circuitry for efficiency and longevity.

6. User Guide and Handling Instructions

6.1 Cleaning

Unspecified chemical cleaners can damage the LED package. If cleaning is necessary post-soldering, immerse the LED in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute. Aggressive solvents or ultrasonic cleaning should be avoided unless specifically qualified.

6.2 Recommended PCB Pad Layout

A recommended land pattern (footprint) for the PCB is provided to ensure proper solder joint formation, mechanical stability, and heat dissipation. Adhering to this design minimizes tombstoning and ensures reliable electrical connection after reflow.

6.3 Tape and Reel Packaging Specifications

The components are supplied in embossed carrier tape with a protective cover tape. Key packaging details include:

• Reel Diameter: 7 inches.
• Pocket Pitch: Defined for 8mm tape.
• Quantity per Reel: 1500 pieces (standard full reel).
• Minimum Pack Quantity: 500 pieces for remainder reels.
• Missing Components: Maximum of two consecutive empty pockets allowed.
• Standards: Packaging conforms to ANSI/EIA-481 specifications.

This packaging is compatible with standard automated surface-mount technology (SMT) assembly equipment.

7. Important Cautions and Application Notes

7.1 Intended Application

This LED is designed for use in standard commercial and consumer electronic equipment. It is not intended for safety-critical applications where failure could jeopardize life or health (e.g., aviation, medical life-support, transportation safety systems). Consultation is required for such high-reliability uses.

7.2 Storage Conditions

Sealed Package: Store at ≤30°C and ≤90% Relative Humidity (RH). The shelf life in the moisture-proof bag with desiccant is one year.
Opened Package: For components removed from their moisture-barrier bag, the storage environment must not exceed 30°C and 60% RH. Components should be subjected to IR reflow within one week (Moisture Sensitivity Level 3, MSL 3). For storage beyond one week, use a sealed container with desiccant or a nitrogen desiccator. Components stored out of bag for more than a week require baking at approximately 60°C for at least 20 hours prior to soldering to prevent \"popcorning\" during reflow.

7.4 Soldering Guidelines

Detailed soldering parameters are critical for reliability.

• Reflow Soldering (Recommended):
  • Pre-heat Temperature: 150-200°C
  • Pre-heat Time: Up to 120 seconds.
  • Peak Temperature: 260°C maximum.
  • Time Above Liquidus: 10 seconds maximum.
  • Number of Passes: Maximum of two reflow cycles.
• Hand Soldering (Iron):
  • Iron Tip Temperature: 300°C maximum.
  • Contact Time: 3 seconds maximum per pad.
  • Number of Repairs: One time only.

The optimal reflow profile depends on the specific PCB design, solder paste, and oven. The provided parameters are based on JEDEC standards and serve as a reliable starting point. Characterization for the specific assembly line is recommended.

7.5 Drive Method

LEDs are current-driven devices. To ensure uniform brightness when connecting multiple LEDs in parallel, a current-limiting resistor must be placed in series with each individual LED. Driving LEDs directly from a voltage source without current regulation leads to inconsistent brightness and potential overcurrent damage due to the natural variation in forward voltage (VF) from device to device. The series resistor value is calculated using Ohm's Law: R = (Vsource - VF_LED) / Idesired.

8. Application Suggestions and Design Considerations

8.1 Thermal Management

While the power dissipation is relatively low at 75mW, effective thermal management on the PCB is important for maintaining long-term reliability and stable light output, especially at high ambient temperatures or when driven at maximum current. Ensuring adequate copper area around the LED pads helps dissipate heat.

8.2 Optical Design

The 25-degree viewing angle provides a relatively focused beam. For applications requiring wider illumination, secondary optics such as light guides or diffusers may be necessary. The water-clear lens is suitable for applications where the LED chip itself is not visible, or where color mixing is employed.

8.3 Circuit Protection

In addition to series current-limiting resistors, consider incorporating reverse polarity protection if the power supply connection is user-accessible. Transient voltage suppression (TVS) diodes or other protection circuits may be warranted in electrically noisy environments.

9. Technology and Principle of Operation

This LED is based on Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material. When a forward voltage is applied across the p-n junction, electrons and holes recombine in the active region, releasing energy in the form of photons. The specific composition of the AlInGaP alloy determines the bandgap energy, which directly corresponds to the wavelength of emitted light—in this case, in the red-orange spectrum (approx. 615-621 nm). AlInGaP technology is known for its high internal quantum efficiency and excellent performance in the red to amber color range, offering superior brightness and stability compared to older technologies like GaAsP.

10. Common Questions Based on Technical Parameters

Q: Can I drive this LED at 30mA continuously?
A: Yes, 30mA is the maximum rated continuous DC forward current. For optimal longevity, driving at or below the typical 20mA test condition is often recommended.

Q: What resistor value should I use with a 5V supply?
A: Using the typical VF of 2.0V and a desired current of 20mA: R = (5V - 2.0V) / 0.020A = 150 Ohms. A standard 150Ω resistor would be suitable. Always calculate using the maximum VF (2.4V) to ensure minimum current is sufficient for your application.

Q: How does temperature affect brightness?
A: Luminous intensity decreases as the junction temperature increases. The performance curves show this derating. Adequate heat sinking and avoiding operation at maximum current in high ambient temperatures are key to maintaining consistent output.

Q: Is this LED suitable for pulsed operation?
A: Yes, it can handle a peak forward current of 80mA at a low duty cycle (1/10) with a short pulse width (0.1ms). This can be used for multiplexing or achieving perceived higher brightness.