5mm Round Green LED Lamp LTL2R3TGY3K Datasheet - T-1 3/4 Package - 3.3V Max - 105mW - 530nm Dominant Wavelength - English Technical Document

1. Product Overview

This document details the specifications for a 5mm round through-hole LED lamp. This popular T-1 3/4 package design features a smooth, uniform radiation pattern suitable for applications requiring clear, consistent illumination. The device utilizes advanced InGaN technology to produce green light with a typical dominant wavelength of 530nm, encapsulated in a water-clear epoxy resin.

1.1 Core Advantages and Target Market

The primary advantages of this LED include high luminous intensity output, leading to high emitting efficiency and lower power consumption for energy savings. The package offers superior moisture resistance and contains UV inhibitors, making it robust for use in both indoor and demanding outdoor environments. Key target applications are full-color signboards, billboards, video message signs, traffic signs, and bus signage where reliability and brightness are critical.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

The device is rated for a maximum power dissipation of 105mW at an ambient temperature (TA) of 25°C. The maximum continuous forward current (DC) is 30mA. For pulsed operation, a peak forward current of 100mA is permissible under specific conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms). The operating temperature range is from -30°C to +85°C, with a wider storage range of -40°C to +100°C. A derating factor of 0.45 mA/°C applies linearly from 30°C upwards for the forward current. The maximum reverse voltage is 5V, though the device is not designed for reverse operation.

2.2 Electrical and Optical Characteristics

At a standard test condition of TA=25°C and IF=20mA, the luminous intensity (Iv) ranges from a minimum of 7800 mcd to a typical maximum of 16000 mcd, with a ±15% testing tolerance applied. The forward voltage (VF) ranges from 2.8V to 3.3V. The viewing angle (2θ1/2), defined as the off-axis angle where intensity is half the axial value, is typically 30° with a ±2° measurement tolerance. The peak emission wavelength (λP) is typically 531nm, while the dominant wavelength (λd) ranges from 525nm to 532nm. The spectral line half-width (Δλ) is typically 35nm. Reverse current (IR) is a maximum of 50μA at VR=5V.

3. Binning System Specification

The product is classified according to three key parameters to ensure consistency in application.

3.1 Luminous Intensity Binning

Luminous intensity is categorized into three bins (A, B, C) with minimum and maximum values at IF=20mA: Bin A (7800-9600 mcd), Bin B (9600-12500 mcd), and Bin C (12500-16000 mcd). A tolerance of ±15% applies to each bin limit.

3.2 Dominant Wavelength Binning

Dominant wavelength is binned into three groups (G1, G2, G3): G1 (525-527 nm), G2 (527-530 nm), and G3 (530-532 nm). The tolerance for each bin limit is ±1nm.

3.3 Forward Voltage Binning

Forward voltage is divided into five bins (1 through 5) in 0.1V steps: Bin 1 (2.8-2.9V), Bin 2 (2.9-3.0V), Bin 3 (3.0-3.1V), Bin 4 (3.1-3.2V), and Bin 5 (3.2-3.3V). The tolerance for each bin limit is ±0.07V.

4. Performance Curve Analysis

The datasheet references typical electrical and optical characteristic curves measured at 25°C ambient temperature. These curves visually represent the relationship between key parameters, providing designers with a deeper understanding of device behavior under varying conditions. While specific graphs are not detailed in the provided text, such curves typically include forward current vs. forward voltage (I-V curve), relative luminous intensity vs. forward current, relative luminous intensity vs. ambient temperature, and spectral distribution. Analyzing these curves is essential for predicting performance in real-world applications, especially concerning thermal management and drive current selection.

5. Mechanical and Packaging Information

5.1 Outline Dimensions

The device conforms to the popular T-1 3/4 (5mm) round lamp form factor. Key dimensional notes include: all dimensions are in millimeters (inches); standard tolerance is ±0.25mm (.010\") unless specified; maximum protruded resin under the flange is 1.0mm (.04\"); lead spacing is measured where leads emerge from the package. Designers must refer to the detailed dimensional drawing for precise placement and footprint design.

5.2 Polarity Identification and Lead Forming

Polarity is indicated by the lead configuration (typically the longer lead is the anode). During assembly, leads must be bent 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. Lead forming must be performed at normal temperature and before the soldering process to prevent mechanical stress on the epoxy package.

6. Soldering and Assembly Guidelines

6.1 Soldering Parameters and Process

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

6.2 Storage and Cleaning

For storage, the ambient should not exceed 30°C or 70% relative humidity. LEDs removed from original packaging should be used within three months. For extended storage, use a sealed container with desiccant or a nitrogen ambient. For cleaning, use alcohol-based solvents like isopropyl alcohol.

7. Packaging and Ordering Information

The standard packing specification is 500, 200, or 100 pieces per anti-static packing bag. Ten packing bags are placed per inner carton, totaling 5,000 pieces. Eight inner cartons are packed per outer shipping carton, resulting in a total of 40,000 pieces per outer carton. In every shipping lot, only the last pack may be a non-full pack. The bin classification codes for luminous intensity, dominant wavelength, and forward voltage are marked on each packing bag for traceability.

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

This LED is well-suited for indoor and outdoor signage applications, including full-color signboards, billboards, video message signs, traffic signs, and bus signs. Its high brightness and environmental robustness make it ideal for applications requiring high visibility and long-term reliability.

8.2 Drive Circuit Design

LEDs are current-operated devices. To ensure intensity uniformity when multiple LEDs are connected in parallel, it is strongly recommended to use a current-limiting resistor in series with each LED (Circuit A). Driving multiple LEDs in parallel without individual series resistors (Circuit B) is not recommended, as differences in the forward voltage (I-V) characteristics of individual LEDs will cause uneven current distribution and thus uneven brightness.

8.3 Electrostatic Discharge (ESD) Protection

Static electricity or power surges can damage the LED. Preventive measures include: using a conductive wrist strap or anti-static gloves when handling; ensuring all devices, equipment, and work surfaces are properly grounded; and using an ion blower to neutralize static charges in the work area.

9. Technical Comparison and Differentiation

Compared to standard 5mm LEDs, this device offers a higher typical luminous intensity (up to 16000 mcd), which translates to higher efficiency and potential power savings in signage applications. The inclusion of specific UV inhibitors and enhanced moisture resistance in the epoxy formulation provides a competitive edge for outdoor and harsh environment applications over basic commercial-grade LEDs. The detailed three-dimensional binning system (intensity, wavelength, voltage) allows for tighter color and brightness matching in array applications, a feature critical for high-quality video and message displays.

10. Frequently Asked Questions Based on Technical Parameters

Q: What is the difference between peak wavelength and dominant wavelength?

A: Peak wavelength (λP) is the wavelength at which the emission spectrum has its maximum intensity (531nm typical here). Dominant wavelength (λd) is derived from the CIE chromaticity diagram and represents the single wavelength that best defines the perceived color of the light (525-532nm here). Dominant wavelength is more relevant for color specification.

Q: Can I drive this LED at 30mA continuously?

A: Yes, 30mA is the maximum rated continuous DC forward current at 25°C. However, for reliable long-term operation, especially at higher ambient temperatures, it is advisable to operate below this maximum and apply the specified derating factor (0.45 mA/°C above 30°C).

Q: Why is a series resistor necessary for each LED in parallel?

A> The forward voltage (Vf) of LEDs has a natural variation (as shown in the binning table). Without a series resistor to limit current, LEDs with a slightly lower Vf will draw disproportionately more current than those with a higher Vf when connected in parallel to a common voltage source. This leads to uneven brightness and can overstress the lower-Vf LEDs. The series resistor acts as a simple current regulator for each individual device.

11. Practical Design and Usage Case

Case: Designing a High-Visibility Traffic Warning Sign. A designer needs to create a solar-powered, flashing \"Road Work Ahead\" sign. Using this LED, they would select LEDs from the same luminous intensity bin (e.g., Bin C) and dominant wavelength bin (e.g., G2) to ensure uniform brightness and color across the sign. They would design the drive circuit using a microcontroller to generate the flash pattern, with each LED (or small series string) having its own current-limiting resistor calculated based on the supply voltage (e.g., 12V from a battery) and the LED's forward voltage bin (e.g., Bin 3, Vf ~3.05V). The high luminous intensity ensures the sign is visible in daylight, while the UV-resistant and moisture-resistant package guarantees longevity in an outdoor environment. Careful PCB layout would maintain the minimum 3mm lead bend and solder clearance from the LED body.

12. Principle Introduction

This device is a Light Emitting Diode (LED). It operates on the principle of electroluminescence in a semiconductor material. When a forward voltage is applied across the p-n junction, electrons from the n-type region recombine with holes from the p-type region, releasing energy in the form of photons (light). The specific semiconductor material used here is Indium Gallium Nitride (InGaN), which is engineered to emit photons in the green region of the visible spectrum (around 530nm). The water-clear epoxy package serves to protect the semiconductor chip, act as a lens to shape the light output into a 30° viewing angle, and provide mechanical support for the leads.

13. Development Trends

The trend in through-hole indicator LEDs like this one continues towards higher luminous efficacy (more light output per watt of electrical input), enabling brighter displays with lower energy consumption. There is also a focus on improving color consistency and expanding binning options for precise color matching in full-color applications. While surface-mount device (SMD) technology dominates new designs for miniaturization, through-hole LEDs remain vital for applications requiring robust mechanical mounting, easier manual prototyping, and high single-point brightness in larger packages. The integration of more robust materials for extreme environmental resistance is also an ongoing development area.