4mm Oval Through Hole LED Lamp - Luminous Intensity 520-1500mcd - Forward Voltage 1.8-2.5V - 20mA - Red Color - English Technical Document

1. Product Overview

This document details the specifications for a 4mm oval through-hole LED lamp. This component is designed as a popular, cost-effective solution for applications requiring a uniform viewing angle and high luminous output. Its primary design focus is on reliability and efficiency for both indoor and outdoor use.

1.1 Core Advantages and Target Market

The lamp features a smooth, uniform radiation pattern characterized by a typical viewing angle of 110x50 degrees. This makes it particularly suitable for applications where consistent light distribution is critical from various angles. The device utilizes advanced epoxy technology, which provides good moisture resistance and UV protection. This enhances its durability and makes it suitable for long-term exposure in outdoor environments, reducing performance degradation over time. Key target markets and applications include full-color signboards, billboard signs, message displays, bus signs, and general use in communication, computer, consumer electronics, and home appliance sectors.

2. Technical Parameter Deep Dive

This section provides a detailed, objective interpretation of the electrical, optical, and thermal characteristics defined in the datasheet.

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the limits beyond which permanent damage to the device may occur. These are not conditions for normal operation.

• Power Dissipation (Pd): 75 mW maximum. This is the total power the LED package can dissipate as heat.
• Peak Forward Current (I_F(PEAK)): 90 mA, but only under strict conditions (duty cycle ≤ 1/10, pulse width ≤ 10μs). This rating is for short pulses, not continuous operation.
• DC Forward Current (I_F): 30 mA continuous. This is the recommended maximum current for reliable, long-term operation.
• Derating: The DC forward current must be linearly derated by 0.36 mA for every degree Celsius above 30°C ambient temperature (T_A). For example, at 85°C, the maximum allowable continuous current is significantly lower than 30mA.
• Operating Temperature Range (T_opr): -40°C to +85°C.
• Storage Temperature Range (T_stg): -40°C to +100°C.
• Lead Soldering Temperature: 260°C maximum for 5 seconds, measured 2.0mm from the LED body.

2.2 Electrical and Optical Characteristics

These parameters are measured at a standard test condition of T_A=25°C and I_F=20mA, unless otherwise noted.

• Luminous Intensity (I_V): Ranges from a minimum of 520 mcd to a typical maximum of 1500 mcd. The actual value for a specific unit is determined by its bin code (see Section 4). The measurement includes a ±15% testing tolerance.
• Viewing Angle (2θ_1/2): 110 x 50 degrees (oval pattern). The angle is defined where luminous intensity drops to half its axial value, measured with a ±2-degree tolerance.
• Peak Emission Wavelength (λ_P): Typically 631 nm. This is the wavelength at which the spectral power distribution is highest.
• Dominant Wavelength (λ_d): Ranges from 617 nm to 629 nm, binned into specific codes (H28, H29, H30). This is the single wavelength perceived by the human eye that defines the color (red).
• Spectral Line Half-Width (Δλ): Approximately 20 nm. This indicates the spectral purity of the red light.
• Forward Voltage (V_F): Ranges from 1.8V (min) to 2.5V (max), with a typical value of 2.1V at 20mA.
• Reverse Current (I_R): Maximum 100 μA at a reverse voltage (V_R) of 5V. Critical Note: The device is not designed for reverse operation; this test condition is for characterization only.

3. Binning System Specification

The product is classified into bins based on key performance parameters to ensure consistency within an application.

3.1 Luminous Intensity Binning

At I_F=20mA, LEDs are sorted into four intensity bins. The tolerance for each bin limit is ±15%.

• Bin M: 520 mcd (Min) to 680 mcd (Max)
• Bin N: 680 mcd to 880 mcd
• Bin P: 880 mcd to 1150 mcd
• Bin Q: 1150 mcd to 1500 mcd

3.2 Dominant Wavelength Binning

At I_F=20mA, LEDs are sorted into three wavelength bins to control color consistency. The tolerance for each bin limit is ±1 nm.

• Bin H28: 617.0 nm to 621.0 nm
• Bin H29: 621.0 nm to 625.0 nm
• Bin H30: 625.0 nm to 629.0 nm

The intensity classification code (Iv bin) is marked on each packing bag for traceability.

4. Performance Curve Analysis

The datasheet references typical characteristic curves which are essential for design. While not displayed here, they typically include:

• Relative Luminous Intensity vs. Forward Current (I-V Curve): Shows how light output increases with current, up to the maximum rated limits.
• Relative Luminous Intensity vs. Ambient Temperature: Demonstrates the derating of light output as junction temperature increases.
• Forward Voltage vs. Forward Current: Illustrates the nonlinear relationship, important for calculating series resistor values and power dissipation.
• Spectral Distribution: A graph showing the relative power emitted across wavelengths, centered around the peak wavelength of 631 nm.

Designers should consult these curves to understand performance under non-standard conditions (e.g., different drive currents or temperatures).

5. Mechanical and Packaging Information

5.1 Outline Dimensions

The lamp has a popular T-1 (3mm) diameter package with a 4mm oval lens. Key dimensional notes include:

• All dimensions are in millimeters (inches provided in tolerance).
• General tolerance is ±0.25mm unless specified otherwise.
• Maximum resin protrusion under the flange is 1.0mm.
• Lead spacing is measured where leads emerge from the package body.

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 dimensional drawing. Correct polarity is essential for operation.

5.3 Packing Specifications

The LEDs are packaged for bulk handling:

• Unit Pack: 1000, 500, or 250 pieces per anti-static packing bag.
• Inner Carton: Contains 8 packing bags, totaling 8000 pieces.
• Outer Carton: Contains 8 inner cartons, totaling 64,000 pieces.
• In every shipping lot, only the last pack may be non-full.

6. Soldering and Assembly Guidelines

Proper handling is critical to prevent damage.

6.1 Storage

For extended storage outside the original packaging (beyond 3 months), store in a sealed container with desiccant or in a nitrogen ambient. Storage should not exceed 30°C and 70% relative humidity.

6.2 Cleaning

Use alcohol-based solvents like isopropyl alcohol if cleaning is necessary.

6.3 Lead Forming

Bend leads at a point at least 3mm from the base of the LED lens. Do not use the lens base as a fulcrum. Perform forming before soldering at room temperature. Use minimal clinch force during PCB assembly.

6.4 Soldering Process

Critical Rule: Maintain a minimum clearance of 2mm from the base of the lens to the solder point. Never immerse the lens in solder.

• Soldering Iron: Max temperature 350°C, max time 3 seconds (one time only).
• Wave Soldering: Pre-heat to max 100°C for up to 60 seconds. Solder wave at max 260°C for up to 5 seconds.
• Important: IR reflow is NOT suitable for this through-hole type LED product. Excessive heat or time can cause lens deformation or catastrophic failure.

7. Application and Design Recommendations

7.1 Drive Circuit Design

LEDs are current-operated devices. To ensure uniform brightness when connecting multiple LEDs in parallel, it is strongly recommended to use a current-limiting resistor in series with each LED (Circuit A). Driving multiple LEDs in parallel directly from a voltage source (Circuit B) is not recommended due to variations in individual LED forward voltage (V_F), which will cause significant differences in current and, therefore, brightness.

The series resistor value (R_s) can be calculated using Ohm's Law: R_s = (V_supply - V_F) / I_F. Use the maximum V_F from the datasheet (2.5V) to ensure the current does not exceed the desired I_F (e.g., 20mA) under all conditions.

7.2 Electrostatic Discharge (ESD) Protection

These devices are sensitive to electrostatic discharge. Preventive measures must be implemented:

• Operators must wear grounded wrist straps or anti-static gloves.
• All equipment, worktables, and storage racks must be properly grounded.
• Use an ion blower to neutralize static charge that may build up on the plastic lens.
• Maintain training and certification records for personnel in ESD-protected areas.

7.3 Thermal Management

While the power dissipation is low (75mW max), adhering to the derating curve for forward current is essential for longevity, especially in high ambient temperature environments or enclosed spaces. Ensure adequate ventilation if multiple LEDs are used in a dense array.

8. Technical Comparison and Considerations

Compared to non-diffused or narrower-angle LEDs, this component's key differentiator is its oval, wide (110x50°), and uniform viewing angle, making it ideal for signage where visibility from oblique angles is important. The use of diffused red lens and moisture-resistant epoxy offers a balance of performance and environmental robustness suitable for cost-sensitive outdoor applications. Designers comparing options should focus on the specific luminous intensity bin required for their application's brightness needs and the dominant wavelength bin for color consistency across multiple units.

9. Frequently Asked Questions (Based on Technical Parameters)

Q1: Can I drive this LED at 30mA continuously?

A1: The absolute maximum DC forward current is 30mA at 25°C. However, for reliable operation and longer lifetime, it is advisable to operate below this maximum, typically at 20mA as per the test conditions. Furthermore, the current must be derated for ambient temperatures above 30°C.

Q2: Why is there a ±15% tolerance on the luminous intensity bin limits?

A2: This accounts for measurement variability during production testing. It means a unit from Bin M (520-680mcd) could test as low as 442mcd (520 -15%) or as high as 782mcd (680 +15%) under the same test conditions, though it will be classified and marked according to its nominal bin.

Q3: Can I use this LED with a 5V supply?

A3: Yes, but you MUST use a series current-limiting resistor. For example, to achieve ~20mA with a typical V_F of 2.1V: R = (5V - 2.1V) / 0.020A = 145 Ohms. A standard 150 Ohm resistor would be appropriate. Always calculate using the maximum V_F to ensure current does not exceed the desired limit.

Q4: Is this LED suitable for automotive applications?

A4: The operating temperature range (-40°C to +85°C) covers many automotive environments. However, automotive applications typically require components to meet specific quality and reliability standards (e.g., AEC-Q102) which are not specified in this generic datasheet. Further qualification would be necessary.

10. Practical Application Example

Scenario: Designing a simple "ON" indicator for a device powered by a 12V DC wall adapter.

1. Goal: Drive one LED at approximately 15mA for a balance of brightness and longevity.
2. Calculation: Using the maximum V_F of 2.5V for safety. R_s = (12V - 2.5V) / 0.015A = 633 Ohms. The nearest standard value is 620 Ohms.
3. Recalculation: Actual current with 620Ω and typical V_F of 2.1V: I_F = (12V - 2.1V) / 620Ω ≈ 16.0mA. This is within a safe range.
4. Power in Resistor: P = I² * R = (0.016)² * 620 ≈ 0.16W. Use at least a 1/4W (0.25W) resistor.
5. Assembly: Insert LED into PCB, respecting polarity. Bend leads 3mm from body if needed. Solder, keeping the iron tip >2mm from the lens base for <3 seconds at 350°C.

This example highlights the importance of current limiting, component selection, and proper soldering technique.