Through Hole LED Lamp LTW-1DEEDNJ Datasheet - Red/White - 20mA - 52/72mW - English Technical Document

1. Product Overview

This document details the specifications for a through-hole LED lamp, identified by part number LTW-1DEEDNJ. The device is available in two primary color variants: a red LED with a dominant wavelength centered around 625nm (AlInGaP technology) and a white LED with a common cathode configuration and a diffused lens. Through-hole LEDs of this type are designed for status indication across a broad range of electronic applications, offering design flexibility through various intensity and viewing angle options packaged in standard through-hole form factors.

1.1 Key Features and Target Market

The LED lamp is characterized by low power consumption and high efficiency. It is compliant with environmental standards, being lead-free, RoHS compliant, and halogen-free (with limits for Chlorine and Bromine content). Its primary applications span communication equipment, computers, consumer electronics, and home appliances where reliable and clear visual status indication is required.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

All ratings are specified at an ambient temperature (TA) of 25°C. Exceeding these limits may cause permanent damage.

• Power Dissipation (Pd): Red: 52 mW max; White: 72 mW max. This parameter defines the maximum power the LED can dissipate as heat under continuous operation.
• Forward Current: Continuous DC forward current (IF) is 20 mA for both colors. A peak forward current of 60 mA is permissible under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms).
• Temperature Ranges: Operating: -30°C to +85°C; Storage: -40°C to +100°C.
• Soldering Temperature: Leads can withstand 260°C for a maximum of 5 seconds when measured 2.0mm from the LED body.

2.2 Electrical and Optical Characteristics

Measured at TA=25°C and a standard test current (IF) of 20mA.

• Luminous Intensity (Iv): Red: 110-310 mcd (typical 180 mcd); White: 520-2500 mcd (typical 1500 mcd). Intensity is measured per the CIE eye-response curve, with a guaranteed testing tolerance of ±15%.
• Viewing Angle (2θ1/2): Approximately 60 degrees for both red and white variants, indicating a moderately wide beam.
• Dominant Wavelength (λd): For the red LED: 618-630 nm (typical 624 nm).
• Chromaticity Coordinates: For the white LED, typical coordinates are x=0.26, y=0.24.
• Forward Voltage (VF): Red: 1.6-2.6 V (typical 2.1 V); White: 2.6-3.6 V (typical 3.1 V).
• Reverse Current (IR): Maximum 10 μA at a reverse voltage (VR) of 5V. The device is not designed for reverse bias operation.

3. Binning System Explanation

The LEDs are sorted into bins based on key optical parameters to ensure consistency within a production lot.

3.1 Luminous Intensity Binning

• Red LED: Bins FG (110-180 mcd) and HJ (180-310 mcd).
• White LED: Bins MN (520-880 mcd), PQ (880-1500 mcd), and RS (1500-2500 mcd).

Tolerance for each bin limit is ±15%.

3.2 Wavelength and Chromaticity Binning

• Dominant Wavelength (Red): A single bin R1 covers 618-630 nm, with a ±1nm tolerance on limits.
• Chromaticity (White): Defined by hue ranks G1 and H1, specifying a quadrilateral area on the CIE 1931 chromaticity diagram. The measurement allowance for color coordinates is ±0.01.

4. Performance Curve Analysis

The datasheet references typical characteristic curves (implied on page 4/10). These curves would typically illustrate the relationship between forward current (IF) and forward voltage (VF), the temperature dependence of luminous intensity, and the relative spectral power distribution. Analyzing such curves is crucial for understanding device behavior under non-standard conditions, such as different drive currents or ambient temperatures, which affect output intensity and voltage drop.

5. Mechanical and Packaging Information

5.1 Outline Dimensions and Notes

The LED features a standard radial leaded package. Critical 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. A detailed dimensioned drawing is provided in the original document.

5.2 Polarity Identification

The white LED version uses a common cathode configuration. The longer lead typically denotes the anode. Users must consult the detailed mechanical drawing for definitive polarity identification based on internal chip structure and lead frame design.

6. Soldering and Assembly Guidelines

6.1 Storage and Handling

LEDs should be stored below 30°C and 70% relative humidity. If removed from the original moisture-barrier bag, they should be used within three months. For longer storage, use a sealed container with desiccant or a nitrogen ambient.

6.2 Lead Forming

Bending must occur at least 3mm from the base of the LED lens. The base of the lead frame should not be used as a fulcrum. Forming must be done at room temperature, prior to soldering. Use minimal clinch force during PCB assembly.

6.3 Soldering Process

A minimum clearance of 2mm must be maintained between the solder point and the base of the lens. The lens must not be immersed in solder.

• Soldering Iron: Max temperature 350°C, max time 3 seconds per lead (one time only).
• Wave Soldering: Pre-heat max 100°C for 60s max; solder wave max 260°C for 5s max.

Warning: Excessive temperature or time can deform the lens or cause catastrophic failure. IR reflow is not suitable for this through-hole product.

6.4 Cleaning

If necessary, clean only with alcohol-based solvents like isopropyl alcohol.

7. Packaging and Ordering Information

The standard packing specification is as follows: 500, 200, or 100 pieces per anti-static bag. Ten bags are packed into an inner carton (total 5,000 pcs). Eight inner cartons are packed into an 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 Typical Application Scenarios

This LED is suitable for status indicators on indoor/outdoor signs and general electronic equipment like power strips, network switches, consumer audio/video gear, and home appliances.

8.2 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 individual LED (Circuit A). Driving multiple LEDs in parallel directly from a voltage source (Circuit B) is discouraged due to variations in individual LED forward voltage (VF), which will cause significant differences in current and, consequently, brightness.

8.3 Electrostatic Discharge (ESD) Protection

The LED is susceptible to damage from static electricity or power surges. Handling precautions include using a grounded wrist strap or anti-static gloves, and working on a grounded anti-static mat.

9. Technical Comparison and Differentiation

Compared to non-diffused LEDs, the white version's diffused lens provides a wider, more uniform viewing cone, reducing hotspots. The halogen-free construction differentiates it from standard offerings, catering to applications with stricter environmental requirements. The combination of AlInGaP technology for red (offering high efficiency and stability) with a common cathode white in a single part number provides design flexibility.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED at 30mA for higher brightness?

A: No. The absolute maximum continuous DC forward current is 20mA. Exceeding this rating risks reducing the LED's lifespan or causing immediate failure due to overheating.

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

A: The forward voltage (VF) of LEDs has a manufacturing tolerance (e.g., 2.6-3.6V for white). Without individual resistors, LEDs with a lower VF will draw disproportionately more current, leading to uneven brightness and potential overstress of the lower-VF devices.

Q: What does the "±15% testing tolerance" on luminous intensity mean?

A: It means the measured intensity value for a given unit can vary by ±15% from the nominal bin value stated in the table. This is a measurement system tolerance, not an additional parameter spread.

11. Practical Design and Usage Case

Scenario: Designing a panel with ten white status indicators powered by a 5V rail.

Design Steps:

1. Determine forward current: Use the typical 20mA.

2. Determine typical forward voltage (VF) from datasheet: 3.1V for white.

3. Calculate series resistor value: R = (V_supply - VF) / IF = (5V - 3.1V) / 0.020A = 95 Ohms.

4. Calculate resistor power: P = (V_supply - VF) * IF = 1.9V * 0.020A = 0.038W. A standard 1/8W (0.125W) or 1/10W resistor is sufficient.

5. Critical: Place one 95-ohm resistor in series with each of the ten LEDs. Do not share a single resistor among multiple LEDs.

12. Operating Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light when an electric current passes through them. This phenomenon, called electroluminescence, occurs when electrons recombine with electron holes within the device, releasing energy in the form of photons. The color of the light is determined by the energy band gap of the semiconductor material. The red LED uses an AlInGaP (Aluminum Indium Gallium Phosphide) structure, while the white LED typically uses a blue InGaN (Indium Gallium Nitride) chip coated with a phosphor layer that converts some blue light to yellow and red, combining to produce white light.

13. Industry Trends and Developments

While surface-mount device (SMD) LEDs dominate new designs for miniaturization, through-hole LEDs remain relevant for prototyping, educational kits, repair markets, and applications requiring higher single-point luminance or easier manual assembly. The trend within the through-hole segment continues towards higher efficiency (more lumens per watt), improved color consistency through tighter binning, and broader adoption of environmentally friendly materials like halogen-free compounds. The demand for reliable, low-cost indication solutions in industrial and consumer sectors ensures the continued production and development of these components.