LTL-14FGEAJ3HKP Bicolor LED Lamp Datasheet - Through Hole - Green/Red - 20mA - English Technical Document

1. Product Overview

The LTL-14FGEAJ3HKP is a bicolor, through-hole LED lamp designed for use as a Circuit Board Indicator (CBI). It integrates a black plastic right-angle holder (housing) that mates with the LED component, providing a robust and easy-to-assemble solution for status indication on printed circuit boards (PCBs). The device features a T-1 sized lamp containing both green (yellow-green, 570nm typical) and red (625nm typical) LED chips within a single white diffused lens, allowing for dual-color signaling from a single package.

1.1 Core Features and Advantages

The primary advantages of this LED lamp stem from its design and construction:

• Ease of Assembly: The right-angle holder is specifically designed for straightforward mounting and soldering onto PCBs.
• Enhanced Contrast: The black housing material increases the contrast ratio, making the illuminated LED more visible against the board background.
• Solid-State Reliability: As an LED-based source, it offers long life, shock resistance, and fast switching times compared to traditional incandescent lamps.
• Energy Efficiency: The device operates with low power consumption while providing sufficient luminous intensity for indicator purposes.
• Environmental Compliance: The product is lead-free and compliant with RoHS (Restriction of Hazardous Substances) directives.
• Dual-Color Functionality: The integration of green and red chips in one package saves board space and simplifies inventory compared to using two separate single-color LEDs.

1.2 Target Applications and Markets

This LED lamp is suitable for a wide range of electronic equipment requiring clear, reliable status indication. Key application areas include:

• Communication Equipment: Status lights for network switches, routers, modems, and telecommunication devices.
• Computer Systems: Power, HDD activity, and diagnostic indicators on servers, desktop PCs, and peripherals.
• Consumer Electronics: Indicator lights on appliances, audio/video equipment, and home automation devices.
• Industrial Controls: Machine status, fault detection, and operational mode indicators on control panels, PLCs, and instrumentation.

2. In-Depth Technical Parameter Analysis

Understanding the electrical and optical parameters is crucial for reliable circuit design and ensuring the LED operates within its safe operating area (SOA).

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.

• Power Dissipation (PD): 50 mW maximum for both the green and red chips. Exceeding this can lead to overheating and reduced lifespan.
• Peak Forward Current (IFP): 60 mA maximum, but only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 0.1ms). This rating is for brief surge currents, not continuous operation.
• DC Forward Current (IF): 20 mA maximum continuous current. This is the standard operating current for which most optical characteristics are specified.
• Temperature Ranges: The device can operate from -40°C to +85°C and be stored from -40°C to +100°C.
• Lead Soldering Temperature: The leads can withstand 260°C for a maximum of 5 seconds, provided the soldering point is at least 2.0mm (0.079") away from the LED body/lens.

2.2 Electrical and Optical Characteristics

These are the typical performance parameters measured at TA=25°C and IF=10mA, unless otherwise noted. Note the significant testing tolerance of ±30% applied to luminous intensity (Iv).

For the Green (Yellow-Green) Chip:

• Luminous Intensity (Iv): Typical value is 15 mcd, with a range from 8.7 mcd (Min) to 29 mcd (Max).
• Viewing Angle (2θ1/2): 120 degrees. This wide angle ensures good visibility from various viewing positions.
• Peak Emission Wavelength (λP): 574 nm.
• Dominant Wavelength (λd): 570 nm typical, ranging from 565 nm to 574 nm.
• Spectral Line Half-Width (Δλ): 20 nm, indicating the spectral purity of the emitted light.
• Forward Voltage (VF): 2.5 V typical.
• Reverse Current (IR): 100 µA maximum at VR=5V. Important: The device is not designed for reverse operation; this parameter is for test purposes only.

For the Red Chip:

• Luminous Intensity (Iv): Typical value is 14 mcd, with a range from 3.8 mcd (Min) to 30 mcd (Max).
• Viewing Angle (2θ1/2): 120 degrees.
• Peak Emission Wavelength (λP): 632 nm.
• Dominant Wavelength (λd): 625 nm typical, ranging from 614 nm to 632 nm.
• Spectral Line Half-Width (Δλ): 20 nm.
• Forward Voltage (VF): 2.0 V typical.
• Reverse Current (IR): 100 µA maximum at VR=5V.

3. Binning System Explanation

To manage natural variations in the manufacturing process, LEDs are sorted into performance bins. This allows designers to select parts that meet specific intensity and color requirements.

3.1 Luminous Intensity Binning

The LEDs are binned based on their measured luminous intensity at 10mA.

• Green (Yellow-Green) Bins (G1, G2, G3): These bins categorize intensity from a minimum of 8.7 mcd (G1 Min) up to a maximum of 29 mcd (G3 Max).
• Red Bins (R1, R2, R3, R4): These bins categorize intensity from a minimum of 3.8 mcd (R1 Min) up to a maximum of 30 mcd (R4 Max).
• Tolerance: A ±30% tolerance is applied to the limits of each bin, meaning the actual intensity of a binned part can vary by this amount from the stated bin limits.

3.2 Dominant Wavelength Binning

The LEDs are also binned based on their dominant wavelength, which directly correlates with perceived color.

• Green (Yellow-Green) Bins (A1, A2, A3, A4): These bins cover the wavelength range from 565.0 nm (A1 Min) to 574.0 nm (A4 Max). The typical target is 570 nm.
• Red Bin (B1): The red chips are grouped into a single wide bin covering 614.0 nm to 632.0 nm, with a typical target of 625 nm.
• Tolerance: A tighter ±1 nm tolerance is applied to the wavelength bin limits.

4. Mechanical and Packaging Information

4.1 Outline Dimensions and Construction

The device consists of a T-1 LED lamp (approx. 3mm diameter lens) inserted into a black plastic right-angle holder. The holder provides mechanical stability and facilitates PCB mounting. Key dimensional notes include:

• All dimensions are in millimeters (with inch equivalents).
• Standard tolerance is ±0.25mm (±0.010") unless otherwise specified on the dimensioned drawing (not provided in text but referenced).
• The housing material is black plastic.
• The lens is white and diffused, which helps blend the light from the two internal chips and provides a uniform appearance when either color is lit.

4.2 Polarity Identification and Lead Forming

While not explicitly detailed in the text, through-hole LEDs typically have a longer anode (+) lead and a flat spot on the lens rim near the cathode (-) lead for polarity identification. The datasheet provides critical guidelines for lead forming:

• Bending must be done at a point at least 3mm from the base of the LED lens.
• The base of the lead frame must not be used as a fulcrum during bending.
• Lead forming must be performed before soldering and at room temperature.
• During PCB insertion, use the minimum clinch force necessary to avoid imposing excessive mechanical stress on the LED body.

5. Soldering and Assembly Guidelines

Proper handling is essential to prevent damage during the assembly process.

5.1 Recommended Soldering Conditions

Soldering Iron Method:

• Temperature: Maximum 350°C.
• Time: Maximum 3 seconds per solder joint.
• Position: The soldering point must be no closer than 2mm from the base of the epoxy lens/holder.

Wave Soldering Method:

• Pre-heat Temperature: Maximum 160°C.
• Pre-heat Time: Maximum 120 seconds.
• Solder Wave Temperature: Maximum 265°C.
• Soldering Time: Maximum 10 seconds.
• Dipping Position: The solder must not come closer than 2mm from the base of the epoxy lens/holder.

Critical Note: Infrared (IR) reflow soldering is explicitly stated as not suitable for this through-hole type LED product. Excessive temperature or time can deform the lens or cause catastrophic failure.

5.2 Storage and Cleaning

• Storage: For long-term storage outside the original packaging (beyond 3 months), store in a sealed container with desiccant or in a nitrogen-desiccator. Ambient should not exceed 30°C or 70% relative humidity.
• Cleaning: If necessary, clean only with alcohol-based solvents like isopropyl alcohol.

6. Application Design and Drive Considerations

6.1 Drive Circuit Design

LEDs are current-driven devices. To ensure consistent brightness and longevity, a current-limiting resistor must be used in series with each LED.

• Recommended Circuit (Circuit A): A series resistor for each individual LED. This is the preferred method as it compensates for the natural variation in the forward voltage (VF) of individual LEDs, ensuring uniform current and therefore uniform brightness when multiple LEDs are used in parallel.
• Non-Recommended Circuit (Circuit B): Connecting multiple LEDs in parallel with a single shared current-limiting resistor. This is discouraged because small differences in the I-V characteristics of each LED will cause current to divide unevenly, leading to significant differences in brightness between the LEDs.

The value of the series resistor (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where V_F is the typical forward voltage of the LED (2.5V for green, 2.0V for red) and I_F is the desired forward current (e.g., 10mA or 20mA max).

6.2 Electrostatic Discharge (ESD) Protection

LEDs are sensitive to electrostatic discharge. To prevent ESD damage during handling and assembly:

• Operators should wear conductive wrist straps or anti-static gloves.
• All equipment, workbenches, and storage racks must be properly grounded.
• Use an ion blower to neutralize static charges that may accumulate on work surfaces or the devices themselves.

7. Performance Curves and Thermal Analysis

The datasheet references typical characteristic curves which are essential for understanding device behavior under different conditions. While the specific graphs are not included in the text, they typically cover:

• Relative Luminous Intensity vs. Forward Current: Shows how light output increases with current, typically in a near-linear relationship up to the maximum rated current.
• Relative Luminous Intensity vs. Ambient Temperature: Demonstrates the derating of light output as the junction temperature increases. LEDs become less efficient at higher temperatures.
• Forward Voltage vs. Forward Current: The I-V curve, showing the exponential relationship. The typical VF is specified at a given current (e.g., 10mA).
• Spectral Distribution: A graph showing the relative intensity of light emitted across different wavelengths, peaking at λP (574nm for green, 632nm for red) with a half-width of Δλ (20nm).

Designers should consider thermal management in their application. While the device itself has no heatsink, ensuring it is not placed near other heat-generating components and allowing for natural airflow will help maintain performance and longevity by keeping the junction temperature low.

8. Packaging and Ordering Information

The product is supplied in packaging suitable for automated assembly, typically on tape and reel or in ammo packs, as indicated by the "Packing Specification" section. The specific packing quantity (e.g., pieces per reel) and reel dimensions would be defined in the corresponding packing specification drawing. The part number LTL-14FGEAJ3HKP uniquely identifies this specific bicolor LED variant with its associated binning and holder characteristics.