Through Hole LED Lamp LTL-R42FGG1H214T Datasheet - Dimensions - Voltage 2.0V - Power 52mW - Yellow-Green Color - English Technical Document

1. Product Overview

This document details the specifications for a through-hole mounted LED lamp, specifically designed as a Circuit Board Indicator (CBI). The device consists of a black plastic right-angle holder (housing) that integrates with the LED component. This design is intended for clear visual status indication on electronic circuit boards.

1.1 Core Features and Advantages

The product offers several key features that enhance its performance and usability in electronic applications:

• High Contrast Design: The black housing material is selected to provide a high contrast ratio against the illuminated LED, improving visibility.
• Diffused Lens: The lens is green and diffused, which helps to soften and spread the emitted light, reducing glare and creating a more uniform appearance.
• Energy Efficiency: The device is characterized by low power consumption while maintaining high luminous efficiency.
• Environmental Compliance: The product is lead-free and compliant with the Restriction of Hazardous Substances (RoHS) directive.
• LED Technology: The light source utilizes an AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor chip, which emits in the yellow-green spectrum.
• Automated Assembly Friendly: The components are supplied in tape and reel packaging, suitable for automated pick-and-place assembly processes.

1.2 Target Applications and Markets

This LED indicator is suitable for a broad range of electronic equipment across multiple industries, including:

• Computer Systems: Status indicators on motherboards, servers, and peripherals.
• Communication Equipment: Signal and status lights in networking hardware, routers, and switches.
• Consumer Electronics: Power-on indicators, function status lights in appliances and audio/video equipment.
• Industrial Controls: Machine status, fault indicators, and panel lighting in automation and control systems.

2. In-Depth Technical Parameter Analysis

This section provides a detailed breakdown of the device's operational limits and performance characteristics under standard test conditions (TA=25°C).

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation at or near these limits is not recommended for reliable performance.

• Power Dissipation (Pd): 52 mW. This is the maximum amount of power the device can safely dissipate as heat.
• Peak Forward Current (I_FP): 60 mA. This current is permissible only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 0.1ms).
• Continuous Forward Current (I_F): 20 mA. This is the recommended maximum current for continuous DC operation.
• Current Derating: Above 30°C ambient temperature, the maximum allowable continuous forward current must be reduced linearly at a rate of 0.27 mA per degree Celsius.
• Operating Temperature Range: -30°C to +85°C. The device is designed to function within this ambient temperature range.
• Storage Temperature Range: -40°C to +100°C.
• Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured 2.0mm (0.079 inches) from the body of the component.

2.2 Electrical and Optical Characteristics

These parameters define the typical performance of the device when operated under specified conditions (I_F = 10mA, TA=25°C).

• Luminous Intensity (I_V): 8.7 mcd (Min), 15 mcd (Typ), 29 mcd (Max). This measures the perceived power of the emitted light. The guarantee includes a ±15% testing tolerance.
• Viewing Angle (2θ_1/2): 100 degrees (Typ). This is the full angle at which the luminous intensity is half the value measured on-axis.
• Peak Emission Wavelength (λ_P): 572 nm (Typ). The wavelength at which the spectral emission is strongest.
• Dominant Wavelength (λ_d): 566 nm (Min), 569 nm (Typ), 574 nm (Max). This is the single wavelength that best represents the perceived color of the light, derived from the CIE chromaticity diagram.
• Spectral Line Half-Width (Δλ): 15 nm (Typ). A measure of the spectral purity or bandwidth of the emitted light.
• Forward Voltage (V_F): 1.6 V (Min), 2.0 V (Typ), 2.5 V (Max). The voltage drop across the LED when conducting the specified forward current.
• Reverse Current (I_R): 100 µA (Max) at a Reverse Voltage (V_R) of 5V. Important: The device is not designed for operation under reverse bias; this test condition is for characterization only.

3. Binning System Specification

To ensure consistency in applications, the LEDs are sorted (binned) according to key optical parameters. This allows designers to select parts that meet specific brightness and color requirements.

3.1 Luminous Intensity Binning

LEDs are categorized into bins based on their measured luminous intensity at I_F = 10mA. Each bin has a tolerance of ±15% on its limits.

• Bin L3: 8.7 mcd (Min) to 12.6 mcd (Max)
• Bin L2: 12.6 mcd (Min) to 19 mcd (Max)
• Bin L1: 19 mcd (Min) to 29 mcd (Max)

3.2 Dominant Wavelength (Hue) Binning

LEDs are also binned by their dominant wavelength to control color consistency. The tolerance for each bin limit is ±1 nm.

• Bin H06: 566.0 nm to 568.0 nm
• Bin H07: 568.0 nm to 570.0 nm
• Bin H08: 570.0 nm to 572.0 nm
• Bin H09: 572.0 nm to 574.0 nm

4. Performance Curve Analysis

While specific graphical data is referenced in the source document, typical performance curves for such LEDs would illustrate the relationship between key parameters. These are essential for detailed circuit design and understanding device behavior under non-standard conditions.

4.1 Typical Characteristic Curves

Designers should expect to analyze curves including:

• Forward Current vs. Forward Voltage (I-V Curve): Shows the exponential relationship, critical for determining the required driving voltage and series resistor value.
• Luminous Intensity vs. Forward Current: Demonstrates how light output increases with current, up to the maximum rating.
• Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as junction temperature increases, which is influenced by ambient temperature and drive current.
• Spectral Distribution: A plot of relative intensity versus wavelength, showing the peak at ~572 nm and the spectral width.
• Viewing Angle Pattern: A polar plot illustrating the angular distribution of emitted light intensity.

5. Mechanical and Packaging Information

5.1 Outline Dimensions

The device features a right-angle through-hole mounting design. Key dimensional notes include:

• All primary dimensions are provided in millimeters, with inches in parentheses.
• A general tolerance of ±0.25mm (±0.010\") applies unless otherwise specified.
• The housing material is black/dark gray plastic.
• The integrated LEDs are yellow-green with a green diffused lens.

5.2 Packing Specification

The components are supplied for automated assembly.

• Carrier Tape: Made from black conductive polystyrene alloy, with a thickness of 0.50 mm ±0.06 mm.
• Tape Dimensions: The cumulative tolerance for 10 sprocket hole pitches is ±0.20 mm.
• Reel Quantity: Each standard 13-inch reel contains 350 pieces.
• Reel Dimensions: Standard reel dimensions (e.g., PS6 type) are used for compatibility with automated equipment.

6. Soldering and Assembly Guidelines

Proper handling is crucial to maintain reliability and prevent damage.

6.1 Storage and Cleaning

• Storage: For long-term storage outside the original packaging (beyond 3 months), use a sealed container with desiccant or a nitrogen ambient. Recommended storage conditions are ≤30°C and ≤70% relative humidity.
• Cleaning: If necessary, clean only with alcohol-based solvents like isopropyl alcohol.

6.2 Lead Forming and PCB Assembly

• Bend leads at a point at least 3mm from the base of the LED lens. Do not use the lens base as a fulcrum.
• Perform all lead forming at room temperature and before soldering.
• During PCB insertion, apply the minimum clinch force necessary to avoid mechanical stress on the component.

6.3 Soldering Process

Maintain a minimum distance of 2mm from the base of the lens/holder to the solder point. Avoid immersing the lens in solder.

• Hand Soldering (Iron): Maximum temperature 350°C for no more than 3 seconds per joint.
• Wave Soldering: Maximum preheat temperature 120°C for up to 100 seconds. Maximum solder wave temperature 260°C for no more than 5 seconds. Ensure the solder wave does not contact within 2mm of the lens base.
• Critical Note: Excessive temperature or time can cause lens deformation or catastrophic LED failure. Avoid stress on leads while the LED is hot.

7. Application Design Recommendations

7.1 Drive Circuit Design

LEDs are current-driven devices. To ensure uniform brightness when using multiple LEDs, especially in parallel configurations, it is strongly recommended to use a current-limiting resistor in series with each LED.

• Recommended Circuit (A): Each LED has its own series resistor connected to the voltage supply. This compensates for normal variations in the forward voltage (V_F) between individual LEDs, ensuring they all receive similar current and thus have similar brightness.
• Non-Recommended Circuit (B): Connecting multiple LEDs directly in parallel with a single shared resistor is not advised. Small differences in the I-V characteristics of each LED can cause significant current imbalance, leading to uneven brightness and potential over-current in one device while others are under-driven.

7.2 Electrostatic Discharge (ESD) Protection

LEDs are susceptible to damage from electrostatic discharge. Implement the following precautions in the handling and assembly environment:

• Personnel should wear grounded wrist straps or anti-static gloves.
• All equipment, workstations, and storage furniture must be properly grounded.
• Use ionizers to neutralize static charges that may accumulate on the plastic lens during handling.
• Maintain training and certification programs for personnel working in ESD-protected areas.

7.3 Application Scope and Limitations

This LED is suitable for general indicator applications in both indoor and outdoor electronic signage, as well as standard electronic equipment. The designer must ensure operating conditions (current, temperature) remain within the specified Absolute Maximum Ratings and recommended operating conditions outlined in this document.

8. Technical Comparison and Design Considerations

8.1 Key Differentiators

Compared to basic LED lamps, this product offers integrated features:

• Integrated Housing: The right-angle black holder provides mechanical support, simplifies board layout, and enhances contrast without requiring a separate bezel or light pipe.
• Diffused Output: The built-in diffused lens offers a softer, wider viewing light source compared to clear-lens LEDs, which is often preferable for status indicators.
• Automation-Ready Packaging: Tape and reel packing directly supports high-volume manufacturing processes.

8.2 Design Checklist

• Verify the required luminous intensity and select the appropriate bin (L1, L2, L3).
• Confirm the acceptable color range and select the corresponding wavelength bin (H06-H09).
• Calculate the series resistor value based on the supply voltage (V_supply), the LED's typical V_F (e.g., 2.0V), and the desired operating current (≤20mA DC). Formula: R = (V_supply - V_F) / I_F.
• Ensure PCB layout provides the mandated 2mm clearance between the solder pad and the component body.
• Plan for heat dissipation if operating near maximum current or in high ambient temperatures, considering the derating curve.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What is the difference between Peak Wavelength and Dominant Wavelength?

Peak Wavelength (λ_P): This is the physical wavelength at which the LED chip emits the most optical power. It is a property of the semiconductor material. Dominant Wavelength (λ_d): This is a calculated value that represents the perceived color of the light as seen by the human eye, based on the CIE color matching functions. For a monochromatic source like this yellow-green LED, they are typically close, but λ_d is the critical parameter for color specification in applications.

9.2 Can I drive this LED with 20mA continuously?

Yes, 20mA is the specified maximum continuous forward current at 25°C ambient. However, for improved long-term reliability and to account for higher ambient temperatures, it is often good practice to drive LEDs at a lower current, such as 10-15mA, if the application's brightness requirements allow it. Remember to apply derating above 30°C ambient.

9.3 Why is a series resistor necessary even if my power supply is current-limited?

A dedicated series resistor provides local, precise current regulation for each LED. It also offers protection against transient voltage spikes and helps balance current in parallel strings. Relying solely on a system-level current-limited supply may not provide adequate protection or balancing for individual LED components, especially if the supply's regulation is not extremely tight or if wiring impedance varies.

10. Practical Application Example

10.1 Designing a Dual-Status Indicator Panel

Scenario: A network router requires two status LEDs: "Power On" (steady) and "Network Activity" (blinking). Both need to be clearly visible on a dark panel.

Design Steps:

1. Component Selection: This LED is suitable due to its high-contrast black housing and diffused green light. Select bins for consistent color (e.g., H07) and adequate brightness (e.g., L2).
2. Circuit Design: The router's main board provides a 3.3V rail. For a target current of 10mA:
   
   R = (3.3V - 2.0V) / 0.010A = 130 Ohms. The nearest standard value of 130Ω or 150Ω can be used.
3. PCB Layout: Place the LEDs on the board edge. The right-angle design allows them to point perpendicular to the board, facing the panel cutout. Ensure the solder pads are placed >2mm from the edge of the mounting hole to maintain the required clearance.
4. Driving: The "Power On" LED is connected directly to the 3.3V rail via its series resistor. The "Network Activity" LED is connected to a GPIO pin of the main microcontroller via its series resistor, allowing software-controlled blinking.
5. Result: A clean, reliable indicator solution with uniform color and brightness, easily assembled via automated processes using the tape-and-reel supply.

11. Technical Principles

11.1 LED Operating Principle

A Light Emitting Diode (LED) is a semiconductor p-n junction diode. When a forward voltage is applied, electrons from the n-type material recombine with holes from the p-type material within the active region of the junction. This recombination process releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material used—in this case, AlInGaP for yellow-green emission. The diffused lens over the chip is made of epoxy or similar material that scatters the light, creating a wider, more uniform beam pattern.

12. Industry Trends and Context

12.1 Evolution of Indicator LEDs

While basic indicator LEDs remain essential, trends include a move toward higher efficiency materials (like InGaN for broader colors), lower operating currents, and surface-mount device (SMD) packages for miniaturization. However, through-hole components like this one maintain relevance in applications requiring higher mechanical robustness, easier manual assembly for prototypes or low volumes, or where the right-angle form factor is specifically advantageous for panel mounting. The integration of the housing with the LED, as seen here, represents a value-added approach that simplifies the end-user's assembly process.