T-1 3mm Diffused Green LED Lamp Datasheet - Package Size 3.0mm Dia. - Forward Voltage 2.6V - Power Dissipation 78mW - English Technical Document

1. Product Overview

This document details the specifications for a high-intensity, diffused green LED lamp in a popular T-1 (3mm diameter) through-hole package. Designed for general-purpose indicator applications, this component offers a wide viewing angle and reliable performance in a rugged, industry-standard form factor. It is compliant with RoHS directives, indicating it is free from hazardous substances like lead (Pb). The device is characterized by its selected minimum luminous intensity, ensuring a baseline level of brightness for consistent application performance.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

The device's operational limits are defined at an ambient temperature (T_A) of 25°C. Exceeding these ratings may cause permanent damage.

• Power Dissipation (P_D): 78 mW maximum. This is the total power the device can safely dissipate as heat.
• Continuous Forward Current (I_F): 30 mA maximum under DC conditions.
• Peak Forward Current: 90 mA maximum, permissible only under pulsed conditions with a 1/10 duty cycle and 0.1ms pulse width to prevent overheating.
• Derating: The maximum continuous forward current must be linearly reduced by 0.4 mA for every degree Celsius above 50°C ambient temperature.
• Reverse Voltage (V_R): 5 V maximum. Applying a higher reverse voltage can break down the LED junction.
• Operating & Storage Temperature Range: -55°C to +100°C.
• Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured at a point 2.0mm (0.078\") from the LED body.

2.2 Electrical & Optical Characteristics

Typical performance is specified at T_A=25°C. All values are subject to manufacturing tolerances.

• Luminous Intensity (I_V): Ranges from 25 mcd (minimum) to 85 mcd (maximum), with a typical value of 38 mcd when driven at a forward current (I_F) of 10mA. The measurement uses a sensor/filter approximating the CIE photopic eye-response curve. A tolerance of ±15% should be applied to guaranteed intensity values.
• Viewing Angle (2θ_1/2): 85 degrees. This is the full angle at which the luminous intensity drops to half of its axial (on-center) value, characteristic of a diffused lens for wide-angle visibility.
• Peak Emission Wavelength (λ_P): 565 nm.
• Dominant Wavelength (λ_d): Ranges from 565 nm (minimum) to 575 nm (maximum), with a typical value of 570 nm. This is the single wavelength perceived by the human eye to define the color, derived from the CIE chromaticity diagram.
• Spectral Line Half-Width (Δλ): 30 nm (typical). This indicates the spectral purity or bandwidth of the emitted green light.
• Forward Voltage (V_F): 2.6V maximum at I_F = 20mA, with a typical value of 2.1V.
• Reverse Current (I_R): 100 µA maximum at V_R = 5V.
• Capacitance (C): 35 pF typical, measured at zero bias (V_F=0) and a frequency of 1 MHz.

3. Binning System Explanation

The product is sorted into bins based on key optical parameters to ensure consistency within an application. Two separate binning tables are provided, likely for different semiconductor material systems (AllnGaP for Yellow/Green and InGaN for Blue), with this specific part falling under the relevant green specification.

3.1 Luminous Intensity Binning

For the relevant material, intensity is binned at I_F = 10mA. Bin codes range from 3Z (25-30 mcd) to D (65-85 mcd). The tolerance for measurement precision is ±15%.

3.2 Wavelength Binning

Dominant wavelength is binned in 1-3 nm steps. Bin codes range from H05 (565.0-566.0 nm) to H09 (572.0-575.0 nm), with a measurement tolerance of ±1 nm. This allows for precise color selection.

4. Performance Curve Analysis

The datasheet references typical characteristic curves (e.g., relative luminous intensity vs. forward current, forward voltage vs. temperature, spectral distribution). These graphs are essential for design engineers to understand non-linear behaviors, such as how light output and voltage drop change with drive current and ambient temperature, enabling optimal circuit design for efficiency and longevity.

5. Mechanical & Package Information

5.1 Package Dimensions

The device uses a standard T-1 (3mm diameter) round package with diffused lens. Key dimensional notes include: all dimensions in mm (inches), a general tolerance of ±0.25mm, a maximum resin protrusion under the flange of 1.0mm, and lead spacing measured at the package exit point.

5.2 Polarity Identification

For through-hole LEDs, the cathode is typically identified by a flat spot on the lens rim, a shorter lead, or other marking. The specific identification method should be verified from the package drawing referenced in the datasheet.

6. Soldering & Assembly Guidelines

6.1 Lead Forming

Bending must be done at room temperature, before soldering, at a point at least 3mm from the base of the LED lens. The leadframe base must not be used as a fulcrum to avoid stress on the internal die attach.

6.2 Soldering Process

Hand Soldering (Iron): Maximum temperature 300°C for a maximum of 3 seconds per lead. Wave Soldering: Pre-heat to a maximum of 100°C for up to 60 seconds, followed by a solder wave at a maximum of 260°C for up to 5 seconds. A minimum clearance of 3mm must be maintained from the lens base to the solder point. Dipping the lens into solder must be avoided to prevent epoxy wicking. IR reflow is explicitly stated as unsuitable for this through-hole product.

6.3 Storage & Cleaning

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

7. Packaging & Ordering Information

The standard packing quantities are 1000, 500, 200, or 100 pieces per anti-static bag. Ten bags are packed per inner carton (total 5000 pcs). Eight inner cartons are packed per outer shipping carton (total 40,000 pcs). The last pack in a shipping lot may be a non-full pack.

8. Application Recommendations

8.1 Intended Use & Cautions

This LED is intended for ordinary electronic equipment (office, communication, household). It is not recommended for safety-critical applications (aviation, medical, transportation control) without prior consultation, as failure could jeopardize life or health.

8.2 Drive Circuit Design

LEDs are current-operated devices. To ensure uniform brightness when connecting multiple LEDs in parallel, a current-limiting resistor must be used in series with each LED (Circuit Model A). Connecting LEDs directly in parallel (Circuit Model B) is not recommended due to variations in individual forward voltage (V_F), which will cause uneven current distribution and differing brightness.

8.3 Electrostatic Discharge (ESD) Protection

The LED is susceptible to damage from static electricity. Preventive measures include: using grounded wrist straps and workstations, employing ion blowers to neutralize static on lens surfaces, and handling devices in ESD-safe environments.

9. Technical Comparison & Differentiation

This device's primary advantages in its class include its high intensity for a diffused T-1 package, wide 85-degree viewing angle for broad visibility, and RoHS compliance. The provision of detailed binning tables for both intensity and wavelength allows for tighter design control compared to non-binned or loosely specified alternatives, which is crucial for applications requiring color or brightness consistency across multiple indicators.

10. Frequently Asked Questions (FAQ)

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

A: Peak wavelength (λ_P) is the point of maximum power in the emission spectrum. Dominant wavelength (λ_d) is the single wavelength the human eye perceives the color to be, calculated from color coordinates. λ_d is more relevant for color indication applications.

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

A: Yes, but only at or below an ambient temperature of 50°C. Above 50°C, the current must be derated by 0.4mA/°C. At 80°C, for example, the maximum continuous current would be 30mA - (0.4mA * (80-50)) = 18mA.

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

A: The forward voltage (V_F) of LEDs has a natural variation. Without individual resistors, LEDs with a slightly lower V_F will draw disproportionately more current, becoming brighter and potentially overheating, while those with higher V_F will be dim. The resistor dominates the current regulation, minimizing the effect of V_F differences.

11. Practical Design Case Study

Scenario: Designing a panel with 10 uniformly bright green status indicators powered by a 5V rail.

Design Steps:

1. Select LEDs from the same intensity bin (e.g., Bin B: 38-50 mcd) for consistency.

2. Determine drive current. For good brightness and longevity, choose I_F = 10mA.

3. Calculate series resistor. Using typical V_F = 2.1V at 10mA: R = (V_supply - V_F) / I_F = (5V - 2.1V) / 0.01A = 290 Ω. Use the nearest standard value (e.g., 300 Ω).

4. Calculate resistor power: P = I² * R = (0.01)² * 300 = 0.03W. A standard 1/8W (0.125W) resistor is sufficient.

5. Implement: Use ten identical circuits, each with one LED and one 300Ω resistor connected between the 5V rail and ground.

This approach ensures uniform brightness regardless of minor V_F variations between the 10 LEDs.

12. Operating Principle Introduction

A Light Emitting Diode (LED) is a semiconductor p-n junction device. When a forward voltage exceeding its threshold is applied, electrons and holes recombine at the junction, releasing energy in the form of photons (light). The color of the emitted light is determined by the bandgap energy of the semiconductor material used. In this case, the material system produces photons in the green spectrum (~565-575 nm). The diffused epoxy lens scatters the light, creating the wide viewing angle.

13. Technology Trends

The through-hole LED lamp remains a staple for prototyping, educational kits, and applications requiring manual assembly or high reliability in harsh environments where wave soldering is preferred. The industry trend, however, is strongly towards surface-mount device (SMD) packages for mainstream electronics due to their smaller size, suitability for automated pick-and-place assembly, and higher-density PCB layouts. Advancements continue in materials (improving efficiency and color gamut) and packaging (enhancing thermal management for higher power).