LTL-R42FGY1H106T LED Lamp Datasheet - Through Hole - Yellow Green/Yellow - 10mA - English Technical Document

1. Product Overview

The LTL-R42FGY1H106T is a Circuit Board Indicator (CBI) component. It consists of a black plastic right-angle holder (housing) designed to mate with specific LED lamps. This design facilitates easy assembly onto printed circuit boards (PCBs). The product is available in configurations supporting top-view or right-angle mounting and can be arranged in horizontal or vertical arrays, offering stackability for design flexibility.

1.1 Key Features

• Engineered for simplified circuit board assembly processes.
• Black housing material enhances the visual contrast ratio of the illuminated indicator.
• Operates with low power consumption while maintaining high efficiency.
• Manufactured as a lead-free product and is compliant with RoHS (Restriction of Hazardous Substances) directives.
• Utilizes T-1 sized lamps: LED1 emits a yellow-green color using an AlInGaP 569nm chip, and LED2 emits a yellow color using an AlInGaP 589nm chip.

1.2 Target Applications

This component is suitable for a wide range of electronic equipment, including but not limited to:

• Computer systems and peripherals
• Communication devices
• Consumer electronics
• Industrial equipment and controls

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

The following ratings define the limits beyond which permanent damage to the device may occur. Operation under or at these conditions is not guaranteed.

• Power Dissipation (P_d): 52 mW (for both Yellow Green and Yellow LEDs). This is the maximum power the LED can dissipate as heat.
• Peak Forward Current (I_FP): 60 mA. This current can only be applied under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10μs).
• DC Forward Current (I_F): 20 mA. This is the maximum continuous forward current recommended for reliable operation.
• Operating Temperature Range (T_opr): -40°C to +85°C. The device is functional within this ambient temperature range.
• Storage Temperature Range (T_stg): -45°C to +100°C.
• Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured 2.0mm (0.079\") from the LED body.

2.2 Electrical and Optical Characteristics

These parameters are specified at an ambient temperature (T_A) of 25°C and represent typical device performance under standard test conditions.

• Luminous Intensity (I_V): LED1 (Yellow Green): 15 mcd (typical). LED2 (Yellow): 14 mcd (typical). Measured at I_F = 10mA with a ±15% testing tolerance. The measurement uses a sensor/filter approximating the CIE photopic eye-response curve.
• Viewing Angle (2θ_1/2): 100 degrees (typical) for both LED colors. This is the full angle at which luminous intensity drops to half its axial (on-axis) value.
• Peak Emission Wavelength (λ_P): LED1: 572 nm. LED2: 591 nm. This is the wavelength at the highest point in the emission spectrum.
• Dominant Wavelength (λ_d): LED1: 570 nm (typical), range 566-573 nm. LED2: 588 nm (typical), range 584-593 nm. This single wavelength best describes the perceived color, derived from the CIE chromaticity diagram (±1nm tolerance).
• Spectral Line Half-Width (Δλ): 15 nm (typical) for both, indicating the spectral purity.
• Forward Voltage (V_F): 2.0V (typical), with a maximum of 2.6V for both LEDs at I_F = 10mA.
• Reverse Current (I_R): 10 μA (maximum) at a Reverse Voltage (V_R) of 5V. Important: This device is not designed for operation under reverse bias; this test condition is for characterization only.

3. Performance Curve Analysis

The datasheet provides typical characteristic curves for both LED types. These curves are essential for understanding device behavior under varying conditions.

3.1 LED1 (Yellow Green) Curves

Typical plots for the Yellow Green LED would include:
- Relative Luminous Intensity vs. Forward Current: Shows how light output increases with current, typically in a sub-linear relationship at higher currents due to heating.
- Forward Voltage vs. Forward Current: Demonstrates the diode's I-V characteristic.
- Relative Luminous Intensity vs. Ambient Temperature: Illustrates the decrease in light output as junction temperature rises.
- Spectral Distribution: A graph showing the intensity of emitted light across wavelengths, centered around 572 nm.

3.2 LED2 (Yellow) Curves

Similar characteristic curves are provided for the Yellow LED, with key parameters like peak wavelength shifted to 591 nm. The shape of the curves (I-V, intensity vs. current/temperature) will be analogous but with values specific to the yellow chip's characteristics.

4. Mechanical and Packaging Information

4.1 Outline Dimensions

The component features a through-hole right-angle design. Critical dimensional notes include:
- All dimensions are provided in millimeters, with inches in parentheses.
- Standard tolerance is ±0.25mm (0.010\") unless otherwise specified.
- The holder (housing) material is black or dark gray plastic, rated UL 94V-0 for flammability.
- LED1 has a green diffused lens for yellow-green emission; LED2 has a yellow diffused lens.

4.2 Polarity Identification

While not explicitly detailed in the provided text, through-hole LEDs typically have a longer anode (+) lead and a shorter cathode (-) lead. The housing may also have a flat side or other marking near the cathode. Correct polarity must be observed during PCB insertion.

5. Soldering and Assembly Guidelines

5.1 Storage

For optimal shelf life, store LEDs in an environment not exceeding 30°C or 70% relative humidity. If removed from the original moisture barrier bag, use within three months. For longer storage outside the original packaging, use a sealed container with desiccant or a nitrogen-filled desiccator.

5.2 Cleaning

If cleaning is necessary, use alcohol-based solvents such as isopropyl alcohol.

5.3 Lead Forming

If leads need to be bent, do so at a point at least 3mm from the base of the LED lens. Do not use the lens base or lead frame as a fulcrum. Lead forming must be completed at room temperature and before the soldering process.

5.4 Soldering Parameters

A minimum clearance of 2mm must be maintained between the solder point and the base of the lens/holder. Avoid immersing the lens/holder in solder.

• Soldering Iron: Max. temperature 350°C, max. time 3 seconds per lead (one time only).
• Wave Soldering: Pre-heat to max. 120°C for up to 100s. Solder wave at max. 260°C for up to 5s. Dipping position no lower than 2mm from the epoxy bulb base.
• Reflow Soldering (Profile for Reference):
  • Preheat/Soak: 150°C min to 200°C max over max. 100s.
  • Time above liquidous (T_L=217°C): 60-90s.
  • Peak Temperature (T_P): 250°C max.
  • Time within 5°C of classification temp (T_C=245°C): Max. 30s.
  • Total time from 25°C to peak: Max. 5 minutes.

Caution: Excessive soldering temperature or time can deform the lens or cause catastrophic LED failure.

5.5 PCB Assembly

During PCB mounting, apply the minimum clinch force necessary to avoid imposing excessive mechanical stress on the LED body or leads.

6. Drive Method Principle

An LED is a current-operated device. Its light output (luminous intensity) is primarily a function of the forward current (I_F) passing through it. To ensure stable and consistent performance, it is crucial to drive the LED with a constant current source or a voltage source with a series current-limiting resistor. The resistor value can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where V_F is the forward voltage of the LED at the desired operating current. Direct connection to a voltage source without current limiting will likely exceed the maximum DC forward current, leading to rapid degradation or failure.

7. Packaging and Ordering Information

7.1 Packing Specification

The LEDs are supplied in tape-and-reel packaging for automated assembly.

• Carrier Tape: Black Conductive Polystyrene Alloy, thickness 0.50 ±0.06 mm. 10-sprocket hole pitch cumulative tolerance is ±0.20.
• Reel: Standard 13-inch reel containing 350 pieces.

7.2 Carton Specification

• 1 reel is packed with 1 humidity indicator card and 1 desiccant bag inside 1 Moisture Barrier Bag (MBB).
• 1 MBB is packed in 1 Inner Carton. Each Inner Carton contains 2 reels (700 pieces total).
• 10 Inner Cartons are packed in 1 Outer Carton. Each Outer Carton contains 7,000 pieces total (700 pcs * 10).

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

This LED lamp is suitable for indoor/outdoor signage and general electronic equipment. The right-angle design makes it ideal for status indicators on PCBs where the board is mounted perpendicular to the user's line of sight (e.g., on the edge of a computer motherboard or industrial control panel).

8.2 Design Considerations

• Current Limiting: Always implement proper current limiting as described in Section 6.
• Thermal Management: While power dissipation is low (52mW), ensure the operating ambient temperature does not exceed 85°C. In high-density layouts, consider airflow.
• PCB Layout: Follow the recommended keep-out zone (2mm from lens base) for solder mask and traces to prevent soldering issues.
• ESD Precautions: Although not explicitly stated, standard ESD (Electrostatic Discharge) handling procedures should be observed during assembly.

9. Frequently Asked Questions (Based on Technical Parameters)

Q1: What is the difference between Peak Wavelength and Dominant Wavelength?
A1: Peak Wavelength (λ_P) is the literal highest point on the spectral output graph. Dominant Wavelength (λ_d) is derived from color coordinates on the CIE chart and represents the single wavelength of a pure monochromatic light that would appear closest in color to the LED. λ_d is more relevant for color perception.

Q2: Can I drive this LED at 20mA continuously?
A2: Yes, 20mA is the maximum recommended DC forward current. For longer lifespan and reliability, operating at a lower current (e.g., 10mA as used for testing) is often advisable, especially if the full luminous intensity is not required.

Q3: Why is there a ±15% tolerance on luminous intensity?
A3: This is a common manufacturing tolerance for mid-power LEDs. It accounts for normal variations in the epitaxial growth process of the semiconductor chip. For applications requiring consistent brightness, LEDs can be sorted (binned) into tighter intensity groups.

Q4: Is a heat sink required?
A4: For this device with a maximum power dissipation of 52mW, a dedicated heat sink is typically not required under normal operating conditions. However, the PCB itself acts as a heat spreader. Ensuring the leads are properly soldered to adequate copper pads will help dissipate heat.

10. Practical Use Case Example

Scenario: Designing a status indicator for a network router.
The LTL-R42FGY1H106T (using the yellow LED, LED2) is selected to indicate \"Active/Data Transfer\" mode. The router's main PCB provides a 3.3V supply rail (V_supply).
Design Steps:
1. Choose Operating Current: Select I_F = 10mA for a good balance of brightness and longevity.
2. Determine Forward Voltage: From datasheet, V_F (typical) = 2.0V at 10mA.
3. Calculate Series Resistor: R = (3.3V - 2.0V) / 0.010A = 130 Ohms. The nearest standard E24 value is 130Ω or 120Ω. Using 120Ω gives I_F ≈ (3.3-2.0)/120 = 10.8mA, which is acceptable.
4. Calculate Resistor Power: P_R = I² * R = (0.0108)² * 120 ≈ 0.014W. A standard 1/8W (0.125W) or 1/10W resistor is more than sufficient.
5. PCB Layout: Place the resistor in series with the LED's anode. Ensure the LED's cathode is connected to ground. Maintain the 2mm clearance around the LED base in the PCB footprint design.

11. Technology and Development Trends (Objective Overview)

The LTL-R42FGY1H106T utilizes AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor technology. AlInGaP is particularly efficient in the red, orange, amber, and yellow regions of the visible spectrum compared to older technologies like GaAsP. Key trends in this segment include:
- Increased Efficiency: Ongoing material science and chip design improvements yield higher luminous efficacy (more light output per electrical watt).
- Improved Color Consistency: Advances in epitaxial growth and binning processes allow for tighter tolerances on dominant wavelength and luminous intensity.
- Packaging Innovation: While this is a traditional through-hole package, the industry trend is strongly towards surface-mount device (SMD) packages (e.g., 0603, 0805, PLCC) for automated assembly and smaller form factors. Through-hole components remain vital for applications requiring high mechanical strength, manual assembly, or specific optical configurations (like right-angle viewers).
- Reliability Focus: Enhanced packaging materials and manufacturing processes continue to extend operational lifetime and stability under various environmental stresses.