T-1 Through Hole LED Lamp LTL-R14FEGAJHBPT Specification - Bi-Color Yellow Green/Red & White Diffused - 20mA - 52mW - English Technical Datasheet

1. Product Overview

This document details the specifications for a T-1 format through-hole LED lamp designed as a Circuit Board Indicator (CBI). The device is housed in a black plastic right-angle holder (housing) and is characterized by its bi-color emission capability (Yellow Green and Red) combined with a White Diffused lens. The primary design focus is on ease of assembly onto printed circuit boards (PCBs), making it suitable for automated placement processes.

1.1 Core Features and Advantages

• Ease of Assembly: The design is optimized for straightforward circuit board assembly.
• Enhanced Contrast: A black housing material is used to improve the visual contrast ratio of the illuminated indicator.
• Energy Efficiency: The device offers low power consumption coupled with high luminous efficiency.
• Environmental Compliance: This is a lead-free product that complies with RoHS (Restriction of Hazardous Substances) directives.
• Packaging: Supplied in tape and reel packaging compatible with automated assembly equipment.

1.2 Target Applications and Markets

This LED lamp is intended for a broad range of electronic equipment, including but not limited to:

• Computer peripherals and systems
• Communication devices
• Consumer electronics
• Industrial control and instrumentation

2. Technical Parameter Analysis

This section provides a detailed, objective interpretation of the key electrical, optical, and thermal parameters specified for the device. All data is referenced at an ambient temperature (TA) of 25°C unless otherwise stated.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

• Power Dissipation (PD): 52 mW maximum for both Red and Yellow Green LEDs. This parameter is critical for thermal management design.
• Peak Forward Current (IFP): 60 mA maximum, permissible only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms).
• Continuous DC Forward Current (IF): 20 mA maximum. This is the recommended operating current for reliable long-term performance.
• Operating Temperature Range: -40°C to +85°C. The device is rated for industrial-grade temperature environments.
• Storage Temperature Range: -40°C to +100°C.
• Lead Soldering Temperature: Withstands 260°C for a maximum of 5 seconds, measured 2.0mm from the LED body. This is compatible with standard wave or hand soldering processes.

2.2 Electrical and Optical Characteristics

The following parameters are measured under standard test conditions (IF = 10mA). Note that luminous intensity (Iv) specifications include a ±30% testing tolerance.

2.2.1 Luminous Intensity and Viewing Angle

• Yellow Green LED: Typical luminous intensity is 38 mcd, with a range from 23 mcd (Min) to 65 mcd (Max). The typical viewing angle (2θ1/2) is 120 degrees, indicating a wide, diffuse light pattern.
• Red LED: Typical luminous intensity is higher at 60 mcd, ranging from 30 mcd (Min) to 90 mcd (Max).

2.2.2 Spectral Characteristics

• Yellow Green LED: Typical peak emission wavelength (λP) is 574 nm. The typical dominant wavelength (λd) is 570 nm, with a spectral half-width (Δλ) of 20 nm.
• Red LED: Typical peak emission wavelength (λP) is 660 nm. The typical dominant wavelength (λd) is 645 nm, also with a spectral half-width (Δλ) of 20 nm.

2.2.3 Electrical Parameters

• Forward Voltage (VF): For the Yellow Green LED, the typical VF is 2.0V, ranging from 1.6V (Min) to 2.5V (Max) at 10mA. The Red LED's VF is specified within the same range.
• Reverse Current (IR): Maximum of 100 μA at a reverse voltage (VR) of 5V. It is explicitly noted that the device is not designed for reverse operation; this test condition is for leakage current verification only.

3. Bin Table Specification

The product is sorted into bins based on key optical parameters to ensure consistency within a production lot. Designers can specify bins to meet application requirements for brightness and color.

3.1 Luminous Intensity Binning

• Yellow Green (G-Codes):
  • G1: 23 - 38 mcd
  • G2: 38 - 65 mcd
• Red (R-Codes):
  • R1: 30 - 50 mcd
  • R2: 50 - 90 mcd

Tolerance on each bin limit is ±15%.

3.2 Dominant Wavelength Binning

• Yellow Green (A-Codes):
  • A1: 565.0 - 568.0 nm
  • A2: 568.0 - 570.0 nm
  • A3: 570.0 - 572.0 nm
  • A4: 572.0 - 574.0 nm
• Red (B-Code): A single broad bin, B, covering 630.0 - 660.0 nm.

Tolerance on each bin limit is ±1 nm.

4. Performance Curve Analysis

While the provided PDF excerpt references typical characteristic curves, these graphs are essential for in-depth design. They typically illustrate the relationship between forward current and luminous intensity (I-V curve), forward voltage vs. temperature, and the spectral power distribution. Designers use these to predict performance under non-standard operating conditions, such as different drive currents or ambient temperatures.

5. Mechanical and Packaging Information

5.1 Outline Dimensions and Construction

The device uses a T-1 (3mm) lamp form factor mounted in a black or dark gray plastic right-angle holder. Key mechanical notes include:

• All dimensions are in millimeters.
• Standard tolerance is ±0.25mm unless specified otherwise.
• The pin length is specified as 3.0mm.

5.2 Packing Specification

The device is supplied in a format suitable for automated assembly.

• Carrier Tape: Made from black conductive polystyrene alloy, 0.50mm thick.
• Reel: Standard 13-inch (330mm) reel.
• Quantity per Reel: 400 pieces.
• Master Packaging:
  1. One reel is packed with a desiccant and humidity indicator card inside a Moisture Barrier Bag (MBB).
  2. Two MBBs (800 pcs total) are packed in one inner carton.
  3. Ten inner cartons (8,000 pcs total) are packed in one outer carton.

6. Soldering, Assembly, and Handling Guidelines

6.1 Storage Conditions

• Sealed Package (MBB): Store at ≤30°C and ≤70% RH. Use within one year of packing date.
• Opened Package: Store at ≤30°C and ≤60% RH. Components removed from the MBB should undergo IR reflow soldering within 168 hours (7 days).
• Extended Storage (Opened): For storage beyond 168 hours, store in a sealed container with desiccant or in a nitrogen desiccator. A bake-out at 60°C for at least 48 hours is required before soldering to remove absorbed moisture and prevent "popcorning" damage during reflow.

6.2 Cleaning

If cleaning is necessary after soldering, use only alcohol-based solvents such as isopropyl alcohol (IPA). Avoid aggressive or unknown chemical cleaners.

6.3 Lead Forming and PCB Assembly

• Bend leads at a point at least 3mm away from the base of the LED lens. Do not use the lens base as a fulcrum.
• All lead forming must be completed before the soldering process and at room temperature.
• During insertion into the PCB, apply the minimum clinching force necessary to secure the part, avoiding excessive mechanical stress on the LED package.

6.4 Soldering Process

The device is compatible with standard soldering techniques. Adhere to the maximum rating of 260°C for 5 seconds when the leads are soldered. Ensure the soldering iron tip or wave solder contact is at least 2.0mm from the plastic body to prevent heat damage.

7. Application Suggestions and Design Considerations

7.1 Typical Application Scenarios

This bi-color LED is ideal for status indication where multiple states need to be communicated. Common uses include:

• Power/Standby Indicators: Red for standby, Green for power-on.
• System Status: Green for normal operation, Red for fault or warning condition.
• Battery Level Indicators: Multi-segment displays using color to indicate charge level (e.g., Green=high, Red=low).
• Mode Selection Indicators: On control panels for appliances or industrial equipment.

7.2 Circuit Design Notes

• Current Limiting: Always use a series current-limiting resistor. Calculate the resistor value using R = (Vcc - VF) / IF, where VF is the forward voltage of the active color at the desired current (typically 10-20mA).
• Bi-Color Drive: This is a 2-pin, 2-chip device. The two LEDs (Red and Yellow Green) are connected in inverse parallel. Applying forward bias to one pin lights one color; reversing the polarity lights the other color. It cannot display both colors simultaneously.
• Microcontroller Interface: Can be easily driven by microcontroller GPIO pins. Ensure the pin can source/sink the required current, often requiring a transistor driver for higher currents.

8. Technical Comparison and Differentiation

Compared to single-color through-hole LEDs, this bi-color device offers significant space savings on the PCB by combining two indicator functions into one physical footprint. The right-angle holder provides a low-profile mounting solution ideal for applications with height constraints. The inclusion of a white diffused lens on the bi-color chip offers a uniform, wide viewing angle appearance, which can be preferable to clear lenses in many indicator applications.

9. Frequently Asked Questions (Based on Technical Parameters)

1. Q: What is the difference between peak wavelength and dominant wavelength?
   A: Peak wavelength (λP) is the single wavelength at which the emitted optical power is maximum. Dominant wavelength (λd) is the single wavelength perceived by the human eye, calculated from the CIE chromaticity coordinates. λd is more relevant for color indication applications.
2. Q: Can I drive this LED at 20mA continuously?
   A: Yes, 20mA is the maximum continuous DC forward current rating. For optimal longevity and reliability, driving at 10mA (the test condition) or slightly lower is common practice.
3. Q: Why is the storage and handling moisture sensitivity so important?
   A: The plastic packaging can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, causing internal delamination or cracking ("popcorning"). The prescribed baking procedure removes this moisture.
4. Q: How do I select the correct bin code?
   A: Specify a bin code based on your application's need for brightness consistency (G1/G2/R1/R2) and color consistency (A1-A4 for Yellow Green). If color matching across multiple units is critical, a tighter wavelength bin (e.g., A2) should be selected.

10. Practical Design and Usage Case

Scenario: Designing a Network Router Status Panel
A designer needs indicators for "Power," "Internet Connection," and "Wi-Fi Activity." They choose this bi-color LED for the "Internet" indicator. The circuit is designed so that a microcontroller pin drives the LED. When a valid internet connection is established (via Ethernet), the pin outputs a logic high, lighting the Yellow Green LED. If the connection is lost, the firmware switches the pin to logic low, lighting the Red LED. A single 150Ω current-limiting resistor is placed in series with the LED, calculated for a 3.3V supply and a ~2.0V forward voltage at ~10mA. This provides clear, unambiguous status using one component footprint, saving space and cost compared to using two separate single-color LEDs.

11. Operating Principle Introduction

A Light Emitting Diode (LED) is a semiconductor device that emits light when an electric current passes through it. 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 used. In this bi-color device, two different semiconductor chips (one emitting in the red spectrum, one in the yellow-green spectrum) are housed within a single package with a common cathode/anode connection in an inverse-parallel configuration. The white diffused lens is an epoxy dome that scatters the light, creating a wider, more uniform viewing angle and softening the appearance of the individual chip.

12. Technology Trends and Context

While surface-mount device (SMD) LEDs dominate modern high-density electronics, through-hole LEDs like this T-1 type remain relevant in specific sectors. Their key advantages include superior mechanical robustness, easier manual prototyping and repair, and higher permissible soldering temperatures. The trend for such components is towards higher efficiency (more light output per mA), improved color consistency through tighter binning, and enhanced reliability under harsh environmental conditions (wider temperature ranges, higher humidity resistance). The bi-color function in a single package represents an ongoing industry effort to increase functionality while minimizing board space, a principle that bridges through-hole and SMD design philosophies.