LTL-R14FTGFH132T LED Lamp Datasheet - 5mm Right-Angle - 3.0V/2.0V - 75mW/50mW - Green/Red-Orange - English Technical Document

1. Product Overview

The LTL-R14FTGFH132T is a through-hole mounted LED lamp designed for use as a Circuit Board Indicator (CBI). It features a black plastic right-angle holder (housing) that mates with the LED component, providing a solid-state light source suitable for various electronic equipment. The product is designed for ease of assembly onto printed circuit boards (PCBs).

1.1 Core Features and Advantages

• Ease of Assembly: The design is optimized for straightforward circuit board assembly.
• Enhanced Contrast: A black housing improves the visual contrast ratio of the illuminated indicator.
• Solid-State Reliability: Utilizes LED technology for a long-lasting, shock-resistant light source.
• Energy Efficiency: Features low power consumption and high luminous efficiency.
• Environmental Compliance: This is a lead-free product compliant with RoHS directives.
• Optical Design: The T-1 (5mm) lamp is available in two colors: InGaN-based 530nm Green and AlInGaP-based 600nm Red-Orange, both featuring a white diffused lens for a wide viewing angle.

1.2 Target Applications

This LED lamp is intended for a broad range of electronic applications, including but not limited to:

• Communication equipment status indicators.
• Computer and peripheral device status lights.
• Consumer electronics such as audio/video equipment, appliances, and toys.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation at or near these limits is not recommended and may affect reliability.

• Power Dissipation (Pd): Green: 75 mW max; Red-Orange: 50 mW max. This parameter is crucial for thermal management design.
• Peak Forward Current (I_FP): 60 mA for both colors. This is the maximum allowable pulsed current under specific conditions (duty cycle ≤ 1/10, pulse width ≤ 10µs).
• DC Forward Current (I_F): 20 mA for both colors. This is the recommended maximum continuous operating current.
• Operating Temperature Range (T_opr): -30°C to +85°C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature Range (T_stg): -40°C to +100°C.
• Lead Soldering Temperature: 260°C maximum for 5 seconds, measured 2.0mm (0.079") from the LED body. This is critical for hand-soldering or wave-soldering processes.

2.2 Electrical and Optical Characteristics

These parameters are measured at an ambient temperature (T_A) of 25°C and define the typical performance of the device.

• Luminous Intensity (I_v): Measured at I_F = 5mA. Green: Typical 310 mcd (Min 85, Max 400 mcd). Red-Orange: Typical 65 mcd (Min 18, Max 240 mcd). The actual intensity is binned (see Section 4). A ±15% tolerance applies to the guaranteed I_v.
• Viewing Angle (2θ_1/2): Approximately 100 degrees for both colors. This is the full angle at which luminous intensity drops to half its axial (on-axis) value, indicating a wide, diffuse light pattern.
• Peak Wavelength (λ_P): Green: 530 nm; Red-Orange: 611 nm. This is the wavelength at which the spectral emission is strongest.
• Dominant Wavelength (λ_d): Green: 520-535 nm; Red-Orange: 596-612 nm. This is the single wavelength perceived by the human eye, derived from the CIE chromaticity diagram. It is also binned (see Section 4).
• Spectral Line Half-Width (Δλ): Green: 17 nm; Red-Orange: 20 nm. This indicates the spectral purity or bandwidth of the emitted light.
• Forward Voltage (V_F): Measured at I_F = 5mA. Green: Typical 3.0V (Min 2.0V, Max 4.0V). Red-Orange: Typical 2.0V (Min 1.5V, Max 3.0V). This is critical for current-limiting resistor calculation.
• Reverse Current (I_R): Maximum 10 µA at V_R = 5V for both colors.

3. Binning System Explanation

The LEDs are sorted (binned) based on key optical parameters to ensure consistency within a production lot. The bin code is marked on the packing bag.

3.1 Luminous Intensity Binning

LEDs are grouped by their measured luminous intensity at 5mA.

Green LED Bins:
EF: 85 - 140 mcd
GH: 140 - 240 mcd
JK: 240 - 400 mcd

Red-Orange LED Bins:
3Y3Z: 18 - 30 mcd
AB: 30 - 50 mcd
CD: 50 - 85 mcd

Note: Tolerance on each bin limit is ±15%.

3.2 Dominant Wavelength Binning

LEDs are also grouped by their dominant wavelength to control color consistency.

Green LED Wavelength Bins:
1: 520 - 525 nm
2: 525 - 530 nm
3: 530 - 535 nm

Red-Orange LED Wavelength Bins:
1: 596 - 600 nm
2: 600 - 606 nm
3: 606 - 612 nm

Note: Tolerance on each bin limit is ±1 nm.

4. Performance Curve Analysis

Typical performance curves (as referenced in the datasheet) illustrate the relationship between key parameters. These are essential for understanding device behavior under different operating conditions.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

This curve shows the exponential relationship between the current flowing through the LED and the voltage across it. The curve will differ between the green (higher V_F) and red-orange (lower V_F) variants. Designers use this to select an appropriate current-limiting resistor for a given supply voltage.

4.2 Luminous Intensity vs. Forward Current

This curve demonstrates how light output increases with drive current. It is generally linear within the recommended operating range but will saturate at higher currents. Operating above the absolute maximum rating can lead to accelerated degradation or failure.

4.3 Luminous Intensity vs. Ambient Temperature

LED light output decreases as the junction temperature increases. This curve is critical for applications operating over a wide temperature range, as it helps predict the minimum light output at the highest operating temperature.

4.4 Spectral Distribution

These plots show the relative radiant power emitted across the wavelength spectrum for each LED color. The green LED will show a peak around 530nm, while the red-orange LED peaks around 611nm. The half-width values indicate the spread of the spectrum.

5. Mechanical and Packaging Information

5.1 Outline Dimensions

The device uses a standard T-1 (5mm) LED lamp housed in a black plastic right-angle holder. Key dimensional notes include:

• All dimensions are in millimeters (with inches in parentheses).
• Standard tolerance is ±0.25mm (0.010") unless otherwise specified.
• The housing material is black plastic.
• The LED lamp itself has a white diffused lens.

Note: Refer to the detailed dimensional drawing in the original datasheet for specific measurements.

5.2 Polarity Identification

Through-hole LEDs typically have a longer anode (+) lead and a shorter cathode (-) lead. Additionally, the LED housing often has a flat side on the rim near the cathode lead. Correct polarity must be observed during assembly.

5.3 Packaging Specification

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

• Carrier Tape: Made of black conductive polystyrene alloy, 0.50 ±0.06 mm thick.
• Reel Quantities: Available on 13-inch reels containing 100, 200, or 400 pieces.
• Carton Packaging:
  • One reel is packed with a humidity indicator card and desiccant in a Moisture Barrier Bag (MBB).
  • Two MBBs (800 pcs total, assuming 400pc reels) are packed in one Inner Carton.
  • Ten Inner Cartons (8,000 pcs total) are packed in one Outer Carton.

6. Soldering and Assembly Guidelines

6.1 Storage Conditions

• Sealed Package: Store at ≤30°C and ≤70% RH. Use within one year of the package seal date.
• Opened Package: If the Moisture Barrier Bag (MBB) is opened, the storage ambient should not exceed 30°C and 60% RH.
• Floor Life: Components removed from their original MBB should be soldered (e.g., via IR reflow for SMT parts; for through-hole, this refers to general assembly/wave soldering readiness) within 168 hours (7 days).
• Extended Storage/Baking: For components stored out of the original packaging for more than 168 hours, a bake at approximately 60°C for at least 48 hours is recommended before the soldering process to remove absorbed moisture and prevent "popcorning" or other moisture-induced defects.

6.2 Lead Forming and Handling

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

6.3 Soldering Process

• Maintain a minimum clearance of 2mm between the base of the lens and the soldering point.
• Avoid immersing the lens in solder.
• Do not apply external stress to the leads while the LED is at high temperature from soldering.
• Recommended Hand Soldering: Use a soldering iron with temperature control. The tip temperature should be set appropriately for the solder alloy, and the soldering time per lead should be minimized, typically not exceeding 3-5 seconds, respecting the absolute maximum of 260°C for 5 seconds at 2mm from the body.

6.4 Cleaning

If cleaning is required after soldering, use alcohol-based solvents such as isopropyl alcohol. Avoid using aggressive or unknown chemical cleaners that may damage the plastic lens or housing.

7. Application Suggestions

7.1 Typical Application Circuits

The most common application is as a status indicator powered by a DC voltage rail (e.g., 3.3V, 5V, 12V). A current-limiting resistor (R_series) is mandatory and is calculated using Ohm's Law: R_series = (V_supply - V_F) / I_F. Use the typical or maximum V_F from the datasheet for a conservative design. For example, driving a green LED at 5mA from a 5V supply: R = (5V - 3.0V) / 0.005A = 400 Ω. A standard 390 Ω or 430 Ω resistor would be suitable.

7.2 Design Considerations

• Current Drive: For maximum longevity and stable light output, drive the LED at or below the recommended DC forward current (20mA). Using a lower current (e.g., 5-10mA) is common for indicator purposes and improves efficiency and lifespan.
• Thermal Management: While power dissipation is low, ensure adequate airflow in the enclosure if multiple LEDs are used or if ambient temperatures are high. Operating at high currents increases junction temperature, which reduces light output and lifespan.
• Viewing Angle: The 100-degree viewing angle makes this LED suitable for applications where the indicator needs to be visible from a wide range of positions.
• Color Selection: Green LEDs typically appear brighter to the human eye for the same radiant intensity (mcd) compared to red-orange. Consider this for brightness matching in multi-color displays.

8. Technical Comparison and Differentiation

The LTL-R14FTGFH132T offers specific advantages in its category:

• Right-Angle Form Factor: The integrated right-angle black holder differentiates it from standard radial LEDs, providing a built-in spacer and a specific mounting orientation without requiring a separate socket.
• Contrast Enhancement: The black housing is a key feature, significantly improving the contrast between the off-state (black) and on-state (colored light), making the indicator more readable, especially in bright ambient light.
• Binning for Consistency: The provision of detailed luminous intensity and wavelength binning allows designers to select parts for applications requiring tight color or brightness matching across multiple indicators.
• Dual Color Option in Same Package: Offering both a green and a red-orange variant in the same mechanical package simplifies inventory and PCB design for systems using multiple status colors.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What resistor value should I use with a 5V supply?

It depends on the desired current and LED color. For a green LED at 5mA: R ≈ (5V - 3.0V) / 0.005A = 400Ω. For a red-orange LED at 5mA: R ≈ (5V - 2.0V) / 0.005A = 600Ω. Always calculate using the maximum supply voltage and minimum V_F for a conservative design that won't exceed the target current.

9.2 Can I drive this LED at 20mA continuously?

Yes, 20mA is the maximum recommended DC forward current. However, for standard indicator use, 5-10mA is often sufficient and will result in lower power consumption and potentially longer life. Ensure your design does not exceed the absolute maximum power dissipation (75mW for green, 50mW for red-orange) at your chosen current and actual forward voltage.

9.3 Why is there a ±15% tolerance on the luminous intensity?

This tolerance accounts for measurement variations and minor production variances even within a single bin. The binning system (EF, GH, JK, etc.) provides a much tighter guaranteed range. The ±15% applies to the limits of those bins, meaning a part from bin GH (140-240 mcd) is guaranteed to be within 140±15% and 240±15% mcd.

9.4 How critical is the 168-hour floor life after opening the bag?

It is a recommended guideline to prevent moisture-related soldering defects. If the exposed components absorb too much moisture from the ambient air, rapid heating during soldering can cause internal delamination or cracking. If the limit is exceeded, follow the baking procedure (60°C for 48 hours) before soldering.

10. Practical Application Example

Scenario: Designing a multi-status panel for a network router.

A designer is creating a front panel with three indicators: Power (Green), Network Activity (Flashing Green), and Fault (Red-Orange).

1. Component Selection: They select the LTL-R14FTGFH132T for all three positions. The right-angle holder provides a consistent, professional look and eases assembly. The black housing ensures high contrast against the panel.
2. Circuit Design: The system uses a 3.3V MCU rail. For the green "Power" LED, they choose to drive it at 8mA for good visibility. Using the typical V_F of 3.0V: R = (3.3V - 3.0V) / 0.008A = 37.5Ω. A 39Ω resistor is selected. The same calculation is done for the red-orange LED using its V_F of 2.0V.
3. Binning Consideration: To ensure the two green LEDs (Power and Activity) have matched brightness, the designer specifies the same luminous intensity bin (e.g., GH) for both in the Bill of Materials (BOM).
4. PCB Layout: The PCB footprint is designed according to the datasheet's dimensional drawing. The designer ensures the hole spacing and diameter are correct and that there is a clear silkscreen marking for the cathode (flat side).
5. Assembly & Storage: The production team receives the components on tape-and-reel. They ensure the MBB is only opened shortly before the assembly line needs them, adhering to the 168-hour guideline. Any leftover reels are stored in a dry cabinet.

11. Operating Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material in the active region. This recombination process releases energy in the form of photons (light). The specific color (wavelength) of the emitted light is determined by the energy bandgap of the semiconductor materials used in the active region.

• The Green LED in this product uses an Indium Gallium Nitride (InGaN) compound semiconductor, which has a bandgap corresponding to light in the blue-to-green spectrum.
• The Red-Orange LED uses an Aluminium Indium Gallium Phosphide (AlInGaP) compound semiconductor, which has a bandgap corresponding to light in the yellow-to-red spectrum.
• The white diffused lens is made of epoxy or silicone with scattering particles. It serves two purposes: 1) It protects the fragile semiconductor chip, and 2) It scatters the light, broadening the viewing angle and creating a more uniform, softer appearance compared to a clear lens.

12. Technology Trends

While through-hole LEDs like the T-1 package remain vital for many applications, especially in prototyping, industrial controls, and areas requiring manual assembly or high reliability, the broader LED industry trends are relevant:

• Miniaturization: A strong trend towards smaller surface-mount device (SMD) packages (e.g., 0603, 0402) for high-density PCB designs. However, through-hole parts offer superior mechanical strength and are often preferred in high-vibration environments.
• Increased Efficiency: Ongoing improvements in internal quantum efficiency and light extraction techniques lead to higher luminous efficacy (more light output per watt of electrical input) for all LED colors, including green and red.
• Color Consistency and Binning: Advances in epitaxial growth and manufacturing control continue to reduce the variance in wavelength and intensity, leading to tighter bins and reduced need for sorting, though precise binning remains critical for high-end applications.
• Smart Integration: The growth of "smart" indicators that integrate control ICs (for dimming, sequencing, or addressability) directly into the LED package. While this is more common in SMD RGB LEDs, the demand for intelligent status indication may influence future through-hole form factors.

The LTL-R14FTGFH132T represents a mature, reliable, and well-specified component that continues to serve a wide range of fundamental electronic indicator needs effectively.