LTW-R4MLDGDJH234 LED Lamp Datasheet - White Diffused Lens - 20mA Forward Current - 3.2V Typical Forward Voltage - English Technical Documentation

1. Product Overview

This document details the specifications for a through-hole mounted LED lamp assembly. The product consists of a white LED with a diffused lens, housed within a black plastic right-angle holder (housing). This design is specifically intended for use as a Circuit Board Indicator (CBI), providing clear visual status indication in electronic equipment.

1.1 Core Advantages and Target Market

The primary advantages of this LED assembly include its ease of circuit board assembly due to the through-hole design and holder, enhanced visual contrast provided by the black housing, and high efficiency with low power consumption. It is a lead-free product compliant with RoHS directives. The emitted light is white, produced by an InGaN (Indium Gallium Nitride) chip and diffused through a white lens for a uniform appearance.

The target applications span several key electronics sectors, including computers, communication equipment, consumer electronics, and industrial devices, where reliable and clear status indication is required.

2. Technical Parameters: In-Depth Objective Interpretation

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: 108 mW maximum. This is the total power the device can safely dissipate as heat.
• Forward Current: A DC forward current of 30 mA is the maximum continuous current. A higher peak forward current of 100 mA is permissible only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms).
• Thermal Derating: The maximum allowable DC forward current must be linearly reduced by 0.45 mA for every degree Celsius the ambient temperature rises above 30°C.
• Temperature Ranges: The device is rated for operation from -40°C to +85°C and can be stored in environments from -40°C to +100°C.
• Soldering Temperature: During lead soldering, the temperature at a point 2.0mm from the body of the device must not exceed 260°C for more than 5 seconds.

2.2 Electrical and Optical Characteristics

These are the typical performance parameters measured at TA=25°C and a forward current (IF) of 20 mA, which is the standard test condition.

• Luminous Intensity (Iv): Ranges from a minimum of 140 mcd to a maximum of 520 mcd, with a typical value of 300 mcd. The actual intensity for a given unit is classified into bins (see Section 4). The measurement includes a ±15% testing tolerance.
• Viewing Angle (2θ1/2): Defined as the full angle at which intensity drops to half its axial value. It is 130 degrees in the horizontal plane and 120 degrees in the vertical plane, indicating a wide viewing cone.
• Chromaticity Coordinates (x, y): The color point of the white light is defined on the CIE 1931 chromaticity diagram. Typical coordinates are x=0.30, y=0.29. Specific hue ranks are defined in the bin table.
• Forward Voltage (VF): Typically 3.2V, with a range from 2.8V to 3.6V at 20 mA. This parameter is crucial for designing the current-limiting circuitry.
• Reverse Current (IR): Typically 10 μA maximum when a reverse voltage (VR) of 5V is applied. The device is not designed for operation under reverse bias.

3. Binning System Explanation

To ensure consistency in applications, the LEDs are sorted (binned) based on key optical parameters.

3.1 Luminous Intensity Binning

LEDs are classified into bins denoted by letters (G, H, J, K, L) based on their measured luminous intensity at 20 mA. Each bin has a defined minimum and maximum intensity range. A tolerance of ±15% is applied to the bin limits. For example, bin 'J' covers intensities from 240 mcd to 310 mcd.

3.2 Hue (Color) Binning

The white color point is also binned. The datasheet provides chromaticity coordinate ranges for several hue ranks (B1, B2, C1, C2, D1, D2). Each rank is defined by a quadrilateral area on the CIE chromaticity diagram, specified by four (x, y) coordinate pairs. The color coordinate measurement has an allowance of ±0.01.

4. Mechanical and Packaging Information

4.1 Outline Dimensions and Materials

The product features a right-angle through-hole design. The holder (housing) is made from black plastic (material: PA9T). The LED lamp itself is white. All dimensional tolerances are ±0.25mm unless otherwise specified. The exact mechanical drawing is referenced in the original datasheet.

3.2 Packaging Specification

The LEDs are packed in bags containing 400, 200, or 100 pieces. Seven of these bags are placed into an inner carton, totaling 2,800 pieces. Eight inner cartons are then packed into an outer shipping carton, resulting in a total of 22,400 pieces per outer carton. It is noted that in every shipping lot, only the final pack may not be a full pack.

5. Soldering and Assembly Guidelines

Proper handling is critical to ensure reliability and prevent damage.

5.1 Storage and Cleaning

For storage, the ambient should not exceed 30°C or 70% relative humidity. LEDs removed from their original packaging should be used within three months. For longer storage outside the original pack, they should be kept in a sealed container with desiccant or in a nitrogen ambient. If cleaning is necessary, only alcohol-based solvents like isopropyl alcohol should be used.

5.2 Lead Forming and PCB Assembly

If leads need to be bent, this must be done at normal temperature and before soldering. The bend should be made 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 PCB assembly, the minimum possible clinch force should be used to avoid excessive mechanical stress on the component.

5.3 Soldering Process

A minimum clearance of 2mm must be maintained between the base of the lens/holder and the soldering point. The lens/holder must not be dipped into solder. No external stress should be applied to the leads while the LED is at high temperature from soldering.

Recommended Soldering Conditions:

• Soldering Iron: Temperature: 350°C max. Time: 3 seconds max (one time only). Position: No closer than 2mm from the base.
• Wave Soldering: Pre-heat: 120°C max for 100 seconds max. Solder Wave: 260°C max for 5 seconds max. Dipping Position: No lower than 2mm from the base.

Excessive temperature or time can deform the lens or cause catastrophic failure.

6. Application Suggestions and Design Considerations

6.1 Drive Method

LEDs are current-operated devices. To ensure uniform brightness when multiple LEDs are connected in parallel, it is strongly recommended to use a individual current-limiting resistor in series with each LED. Driving multiple LEDs in parallel without individual resistors (as shown in a non-recommended circuit diagram) can result in brightness differences due to natural variations in the forward voltage (I-V characteristics) of each LED.

6.2 Electrostatic Discharge (ESD) Protection

These LEDs are susceptible to damage from static electricity or power surges. To prevent ESD damage: personnel should use conductive wrist straps or anti-static gloves when handling the LEDs; all equipment, devices, and machinery used in the handling and assembly process must be properly grounded.

6.3 Typical Application Scenarios

This LED lamp is suitable for both indoor and outdoor signage applications, as well as for status indication in ordinary electronic equipment. The right-angle holder makes it ideal for applications where the PCB is mounted perpendicular to the viewing direction, such as in front-panel indicators.

7. Technical Comparison and Differentiation

While the datasheet provides specifications for a single part number, key differentiators for this type of product in the market typically include: the use of a dedicated holder for ease of assembly and improved contrast; a wide viewing angle suitable for multi-directional viewing; a defined binning structure for intensity and color for design consistency; and clear, detailed application notes covering soldering, handling, and driving, which aid in design-in reliability.

8. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the purpose of the black housing?
A: The black plastic housing acts as a holder for the LED, simplifying PCB assembly. More importantly, it provides a high-contrast background against the emitted white light, making the indicator more visually distinct.

Q: How do I select the correct current-limiting resistor?
A: Use Ohm's Law: R = (Vsupply - VF) / IF. Use the maximum forward voltage (VF) from the datasheet (3.6V) for a conservative design to ensure the current does not exceed 20mA. For example, with a 5V supply: R = (5V - 3.6V) / 0.020A = 70 Ohms. A standard 68 or 75 Ohm resistor would be appropriate.

Q: Can I drive this LED with a voltage source directly?
A: No. Driving an LED directly with a voltage source is not recommended and is likely to destroy it due to excessive current. An LED must be driven with a current-limited source, most simply achieved using a series resistor as described above.

Q: What does the 'bin code' marked on the packing bag mean?
A: It indicates the luminous intensity bin (e.g., G, H, J) for the LEDs in that bag. Designers can specify a bin code when ordering to ensure all LEDs in their product have a consistent brightness level.

9. Working Principle Introduction

This LED is based on InGaN (Indium Gallium Nitride) semiconductor technology. When a forward voltage is applied across the LED's anode and cathode, electrons and holes recombine within the semiconductor's active region, releasing energy in the form of photons (light). The specific composition of the InGaN layers determines the wavelength of the emitted light, which in this case is in the blue/ultraviolet spectrum. This light then excites a phosphor coating inside the package, which down-converts the light to produce the broad spectrum perceived as white light. The diffused lens scatters this light, creating a uniform, non-glare emission pattern.

10. Development Trends

The general trend in indicator LED technology continues towards higher efficiency (more light output per unit of electrical power), improved color consistency and color rendering index (CRI) for white LEDs, and the development of ever-smaller packages with maintained or improved optical performance. There is also a strong focus on enhanced reliability and longevity under a wider range of environmental conditions. The principles of clear binning, robust mechanical design, and comprehensive application guidance, as seen in this datasheet, remain fundamental to providing reliable components for industrial and consumer electronics.