LTL1NHEG6D Through-Hole LED Lamp Datasheet - T-1 3mm Package - 2.5V Forward Voltage - 625nm Red - 54mW Power - English Technical Document

1. Product Overview

This document details the specifications for a high-brightness, through-hole LED lamp. The device utilizes AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor technology, which is renowned for its high luminous efficiency and excellent performance in the red-orange-yellow wavelength spectrum. The product is designed in the popular T-1 (3mm) diameter package, making it a standard and widely compatible component for status indication and illumination across numerous electronic applications.

The core advantages of this LED include its low power consumption combined with high luminous output, compliance with lead-free and RoHS environmental directives, and a design optimized for ease of integration into through-hole printed circuit boards (PCBs). Its primary target markets encompass communication equipment, computer peripherals, consumer electronics, home appliances, and industrial control systems where reliable, long-lasting visual indicators are required.

2. Technical Parameter Deep-Dive

2.1 Absolute Maximum Ratings

The device is rated for a maximum continuous DC forward current (I_F) of 20 mA at an ambient temperature (T_A) of 25°C. The maximum power dissipation is 54 mW. For pulsed operation, a peak forward current of 60 mA is permissible under a 1/10 duty cycle with a 0.1ms pulse width. The operating temperature range is specified from -30°C to +85°C, with a wider storage range of -40°C to +100°C. The derating factor for forward current is 0.34 mA/°C above 40°C, meaning the maximum allowable continuous current decreases as temperature increases to prevent thermal damage.

2.2 Electrical & Optical Characteristics

Key performance parameters are measured at T_A=25°C and I_F=10mA. The luminous intensity (I_V) has a typical value of 65 millicandelas (mcd), with a minimum of 23 mcd and a maximum of 110 mcd. The forward voltage (V_F) is typically 2.5V, with a maximum of 2.5V. The dominant wavelength (λ_d) is 625 nm, defining its red color, with a peak emission wavelength (λ_p) of 630 nm. The viewing angle (2θ_1/2) is 90 degrees, indicating a wide, diffuse light emission pattern. The spectral line half-width (Δλ) is 20 nm. The maximum reverse current (I_R) is 100 μA at a reverse voltage (V_R) of 5V; it is critical to note that the device is not designed for operation under reverse bias.

3. Binning System Specification

The product employs a binning system to categorize units based on luminous intensity and dominant wavelength, ensuring consistency in application design.

3.1 Luminous Intensity Binning

LEDs are sorted into three intensity bins (ZA, BC, DE) based on measurements at 10mA. The bin limits are: ZA (23-38 mcd), BC (38-65 mcd), and DE (65-110 mcd). A tolerance of ±15% applies to each bin limit.

3.2 Dominant Wavelength Binning

For color consistency, dominant wavelength is binned in 4nm steps. The defined bins are: H28 (617.0-621.0 nm), H29 (621.0-625.0 nm), H30 (625.0-629.0 nm), and H31 (629.0-633.0 nm). A tight tolerance of ±1nm is maintained for each bin limit.

4. Performance Curve Analysis

While specific graphical data is referenced in the datasheet, typical curves for this class of device would illustrate the relationship between forward current and luminous intensity (showing a near-linear increase), forward voltage versus forward current (demonstrating the diode's exponential characteristic), and the variation of luminous intensity with ambient temperature (showing a decrease in output as temperature rises). The spectral distribution curve would show a single peak centered around 630 nm with the specified 20 nm half-width, confirming the pure red color emission.

5. Mechanical & Package Information

The LED is housed in a standard T-1 (3mm) cylindrical epoxy package with a diffused red lens. The outline drawing specifies critical dimensions including lead diameter, lens diameter and height, and lead spacing. The lead spacing is measured where the leads emerge from the package body. Tolerances for mechanical dimensions are typically ±0.25mm unless otherwise noted. A maximum protrusion of resin under the flange is 1.0mm. The device features a flat spot on the lens or a longer lead to indicate the cathode (negative) polarity, which is essential for correct PCB orientation.

6. Soldering & Assembly Guidelines

6.1 Storage & Handling

LEDs should be stored in an environment not exceeding 30°C and 70% relative humidity. If removed from their original moisture-barrier packaging, they should be used within three months. For longer storage, they should be kept in a sealed container with desiccant. To prevent Electrostatic Discharge (ESD) damage, personnel should use grounded wrist straps, workstations should be properly grounded, and ionizers are recommended to neutralize static charge on the plastic lens.

6.2 Lead Forming

Any bending of the leads must be performed at a point at least 3mm away from the base of the LED lens, at room temperature, and before the soldering process. The base of the LED must not be used as a fulcrum during bending.

6.3 Soldering Process

A minimum clearance of 2mm must be maintained between the solder point and the base of the epoxy lens. Dipping the lens into solder must be avoided. Recommended conditions are:
Soldering Iron: Max. 350°C for 3 seconds (one time only).
Wave Soldering: Pre-heat to max. 100°C for 60 seconds, followed by a solder wave at max. 260°C for 5 seconds.
Infrared (IR) reflow soldering is not suitable for this through-hole package type. Excessive temperature or time can cause lens deformation or catastrophic failure.

7. Packaging & Ordering Information

The LEDs are packaged in anti-static bags. Standard packing quantities per bag are 1000, 500, 200, or 100 pieces. Ten bags are packed into an inner carton (totaling up to 10,000 pieces). Eight inner cartons are packed into a master outer shipping carton (totaling up to 80,000 pieces). Non-full packs may be present only in the final pack of a shipping lot. The part number LTL1NHEG6D is used for ordering, with the bin code (e.g., for intensity and wavelength) typically indicated on the packing bag label.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is suitable for status and power indicators in a vast array of devices: network routers/modems, desktop computers and servers, audio/video equipment, kitchen appliances, power tools, and industrial control panels. Its high brightness also makes it appropriate for backlighting small legends or for use in indoor/outdoor informational signs where visibility is key.

8.2 Circuit Design Considerations

LEDs are current-driven devices. To ensure uniform brightness when driving multiple LEDs, it is strongly recommended to use a individual current-limiting resistor in series with each LED (Circuit A). Connecting multiple LEDs directly in parallel (Circuit B) is not advised, as slight variations in their forward voltage (V_F) characteristics will cause uneven current distribution and thus uneven brightness. The series resistor value can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F.

9. Technical Comparison & Differentiation

Compared to older GaP (Gallium Phosphide) based red LEDs, this AlInGaP device offers significantly higher luminous intensity and efficiency for the same drive current. Its 625nm dominant wavelength provides a vibrant, saturated red color. The wide 90-degree viewing angle with a diffused lens ensures good visibility from various angles, unlike narrow-beam LEDs. The through-hole design offers superior mechanical strength and thermal conduction to the PCB compared to some surface-mount alternatives, which can be beneficial in high-vibration environments or for manual prototyping.

10. Frequently Asked Questions (FAQ)

Q: What is the difference between dominant wavelength and peak wavelength?
A: Dominant wavelength (λ_d) is derived from the CIE color chart and represents the single wavelength that best matches the perceived color of the light by the human eye. Peak wavelength (λ_p) is the actual wavelength at which the spectral power output is highest. They are often close but not identical.

Q: Can I drive this LED without a current-limiting resistor?
A: No. Connecting an LED directly to a voltage source will cause excessive current to flow, rapidly destroying the device. A series resistor is mandatory for safe operation.

Q: Why is there a binning system?
A: Manufacturing variations cause slight differences in performance. Binning sorts LEDs into groups with tightly controlled characteristics (intensity, color), allowing designers to select the appropriate bin for their application's consistency requirements.

Q: Is this LED suitable for automotive applications?
A: This standard datasheet does not specify AEC-Q101 automotive qualification. For automotive use, a specifically qualified product variant would be required.

11. Practical Design & Usage Case

Scenario: Designing a cluster of four status indicators for a power supply unit.
Implementation: Each LED (from the DE intensity bin for high visibility) is connected to a 5V rail via a separate series resistor. Using the typical V_F of 2.5V and a target I_F of 10mA, the resistor value is R = (5V - 2.5V) / 0.01A = 250 Ohms. A standard 240 or 270 Ohm resistor would be used. The LEDs are mounted on the PCB with the specified 2mm lead clearance for soldering. This design ensures each LED is driven at the correct current, providing uniform and reliable brightness across all four indicators.

12. Technology Principle Introduction

This LED is based on AlInGaP semiconductor material grown on a substrate. When a forward voltage is applied across the p-n junction, electrons and holes are injected into the active region where they recombine. This recombination process releases energy in the form of photons (light). The specific composition of the AlInGaP alloy determines the bandgap energy of the semiconductor, which directly dictates the wavelength (color) of the emitted light—in this case, red at 625 nm. The epoxy lens serves to protect the semiconductor chip, shape the light output beam (90-degree diffusion), and enhance light extraction efficiency.

13. Technology Development Trends

The general trend in LED technology continues toward higher luminous efficacy (more light output per watt of electrical input), improved reliability, and lower cost. For indicator-type LEDs, there is a steady migration toward surface-mount device (SMD) packages for automated assembly and space savings. However, through-hole LEDs remain vital for applications requiring high mechanical robustness, easier manual assembly for prototyping or repair, and superior thermal management via direct connection to PCB copper layers. Advancements in phosphor technology and chip design also allow modern LEDs to achieve higher color purity and consistency across production batches.