LTLR1DEKVJNNH155T Bi-Color LED Indicator Datasheet - Right Angle Holder - Red/Green - 20mA - English Technical Document

1. Product Overview

This document details the specifications for a bi-color Circuit Board Indicator (CBI). The device consists of a black plastic right-angle housing (holder) designed to mate with a T-1 sized LED lamp. The integrated LED features two chip sources: one emitting in the red spectrum and one in the green spectrum, combined with a white diffused lens for a uniform appearance.

1.1 Core Features and Advantages

• Ease of Assembly: The design is optimized for straightforward circuit board assembly and is stackable for creating arrays.
• Enhanced Contrast: The black housing provides a high contrast ratio, improving the visibility of the illuminated indicator.
• Energy Efficiency: The device features low power consumption.
• Environmental Compliance: This is a lead-free product compliant with RoHS directives.
• Integrated Solution: The package includes a bi-color AlInGaP LED (Red: 631nm, Green: 569nm) with a white diffused lens pre-assembled in the holder.
• Automated Handling: Supplied in tape and reel packaging suitable for automated placement equipment.

1.2 Target Applications and Markets

This indicator is suitable for a broad range of electronic equipment requiring status or signal indication. Primary application markets include:

• Communication Equipment
• Computer and Peripheral Devices
• Consumer Electronics
• Industrial Control Systems

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

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

• Power Dissipation (P_d): 75 mW for both red and green chips. This is the maximum power the LED package can dissipate as heat at an ambient temperature (T_A) of 25°C.
• Forward Current:
  • Continuous DC (I_F): 30 mA maximum for both colors.
  • Peak Pulse (I_FP): 60 mA (Green) and 90 mA (Red), permissible only under strict conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms).
• Thermal Derating: The maximum allowable DC forward current must be reduced linearly by 0.4 mA for every degree Celsius the ambient temperature rises above 50°C. This is critical for reliability at elevated temperatures.
• Temperature Ranges: Operational from -40°C to +100°C; storage from -55°C to +100°C.
• Soldering Temperature: Leads can withstand 260°C for a maximum of 5 seconds, measured 1.6mm from the body.

2.2 Electro-Optical Characteristics

These parameters are measured at T_A=25°C and I_F=20mA, representing typical operating conditions.

• Luminous Intensity (I_v): The typical axial light output is 110 mcd for both colors. Minimum values are 65 mcd, and maximums are 250 mcd (Red) and 450 mcd (Green). A ±30% testing tolerance is applied to intensity guarantees.
• Viewing Angle (2θ_1/2): 45 degrees. This is the full angle at which the intensity drops to half its axial value, defining the beam width.
• Wavelength:
  • Peak Wavelength (λ_P): Approximately 639 nm (Red) and 575 nm (Green). This is the spectral point of maximum radiant power.
  • Dominant Wavelength (λ_d): 631 nm (Red) and 569 nm (Green). This is the single wavelength perceived by the human eye, defining the color point on the CIE chromaticity diagram.
• Spectral Bandwidth (Δλ): 20 nm (Red) and 11 nm (Green). This indicates the spectral purity; a narrower bandwidth means a more saturated color.
• Forward Voltage (V_F): Typically 2.0V (Red) and 2.1V (Green) at 20mA, with a maximum of 2.4V for both. This is crucial for current-limiting resistor calculation.
• Reverse Current (I_R): Maximum 10 µA at a reverse voltage (V_R) of 5V. Important: The device is not designed for reverse-bias operation; this test is for characterization only.

3. Binning System Specification

The devices are sorted (binned) based on key optical parameters to ensure consistency within a production lot.

3.1 Luminous Intensity Binning

Units: mcd @ I_F=20mA. Tolerance on bin limits is ±15%.

• Red LED:
  • Bin DE: 65 – 140 mcd
  • Bin FG: 140 – 250 mcd
• Green LED:
  • Bin DE: 65 – 140 mcd
  • Bin FG: 140 – 250 mcd
  • Bin HJ: 250 – 450 mcd

3.2 Dominant Wavelength Binning (Green Only)

Units: nm @ I_F=20mA. Tolerance on bin limits is ±1 nm.

• Hue Bin H06: 564.0 – 568.0 nm
• Hue Bin H07: 568.0 – 571.0 nm

4. Performance Curve Analysis

The datasheet references typical performance curves which graphically represent relationships between key parameters. While the specific graphs are not reproduced in text, their implications are analyzed below.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

The I-V curve for AlInGaP LEDs typically shows an exponential relationship. The specified V_F at 20mA provides a key operating point. Designers must use a series resistor to set the current, as small changes in voltage can cause large changes in current due to the diode's exponential characteristic.

4.2 Luminous Intensity vs. Forward Current

This curve is generally linear over a significant range. Operating at the recommended 20mA ensures optimal brightness and efficiency. Exceeding the maximum DC current reduces lifetime and efficiency due to increased heat.

4.3 Luminous Intensity vs. Ambient Temperature

The light output of LEDs decreases as junction temperature increases. The thermal derating specification for current (0.4 mA/°C above 50°C) is directly related to managing this effect. For applications in high ambient temperatures, reducing drive current or improving board-level heatsinking is necessary to maintain brightness.

4.4 Spectral Distribution

The specified peak and dominant wavelengths, along with spectral bandwidth, define the color characteristics. The narrower bandwidth of the green chip (11 nm) compared to the red (20 nm) indicates higher color purity for the green emission.

5. Mechanical and Packaging Information

5.1 Outline Dimensions and Notes

• All dimensions are provided in millimeters with inches in parentheses.
• Standard tolerance is ±0.25mm unless otherwise specified.
• Holder material: Black plastic.
• Integrated LED: Bi-color (yellow-green/red) with a white diffused lens.

5.2 Polarity Identification and Lead Forming

The device has standard LED polarity (anode/cathode). During lead forming for board mounting, bends must be made at a point at least 2mm from the base of the LED lens/holder. The base of the lead frame must not be used as a fulcrum. Forming must be done at room temperature and before the soldering process.

5.3 Packing Specification

• Carrier Tape: Black conductive polystyrene alloy, 0.50 ± 0.06 mm thick.
• Reel Capacity: 450 pieces per standard 13-inch reel.
• Carton Packing:
  • 1 Reel is packed with a desiccant and humidity indicator card in a Moisture Barrier Bag (MBB).
  • 2 MBBs are packed in one Inner Carton (total 900 pcs).
  • 10 Inner Cartons are packed in one Outer Carton (total 9,000 pcs).

6. Soldering and Assembly Guidelines

6.1 Storage and Moisture Sensitivity

• Sealed Package: Store at ≤ 30°C and ≤ 70% RH. Use within one year.
• Opened Package: Store at ≤ 30°C and ≤ 60% RH. It is recommended to complete IR reflow soldering within 168 hours (1 week) of opening the MBB.
• Extended Storage/Baking: Components stored out of the original packaging for >168 hours should be baked at approximately 60°C for at least 48 hours before SMT assembly to remove absorbed moisture and prevent \"popcorning\" damage during reflow.

6.2 Cleaning

If cleaning is necessary, use alcohol-based solvents such as isopropyl alcohol. Avoid harsh or aggressive chemicals.

6.3 Soldering Process Parameters

A minimum clearance of 2mm must be maintained between the solder point and the base of the lens/holder.

• Hand Soldering (Iron):
  • Temperature: 350°C maximum.
  • Time: 3 seconds maximum per joint.
  • Limit to one soldering cycle.
• Wave Soldering:
  • Pre-heat: 120°C max for up to 100 seconds.
  • Solder Wave: 260°C max.
  • Contact Time: 5 seconds max.

7. Application Notes and Design Considerations

7.1 Typical Application Circuits

The device is driven by a simple DC circuit. A current-limiting resistor (R_series) is mandatory and is calculated using Ohm's Law: R_series = (V_supply - V_F) / I_F. Use the maximum V_F from the datasheet (2.4V) for a conservative design to ensure current does not exceed the limit. For a 5V supply and target I_F of 20mA: R_series = (5V - 2.4V) / 0.02A = 130 Ohms. A standard 130 or 150 Ohm resistor would be suitable. The bi-color functionality typically requires a 3-pin common-cathode or common-anode configuration, controlled by two separate drive signals.

7.2 Thermal Management

While the power dissipation is low (75mW), continuous operation at high ambient temperatures (>50°C) requires attention. Follow the current derating guideline. Ensure adequate ventilation and avoid placing the indicator near other heat-generating components on the PCB.

7.3 Optical Design

The 45-degree viewing angle and white diffused lens provide a wide, even illumination suitable for front-panel indicators. The black holder offers excellent contrast when unlit. For best visibility, consider the mounting height relative to the panel aperture.

8. Technical Comparison and Differentiation

This product combines several features that differentiate it from basic discrete LEDs:

• Integrated Holder vs. Discrete LED: The pre-assembled right-angle black holder eliminates the need for a separate mounting clip or light pipe, simplifying assembly and improving mechanical stability and contrast.
• Bi-Color in Single Package: Provides two indication colors (Red/Green) in one compact 3-pin package, saving board space compared to using two separate single-color LEDs.
• AlInGaP Technology: Offers high brightness and efficiency with good color saturation, particularly in the red and green spectra, compared to older technologies.
• Tape and Reel Packaging: Enables automated assembly, reducing labor costs and improving placement consistency in high-volume manufacturing.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What is the difference between Peak Wavelength and Dominant Wavelength?

Peak Wavelength (λ_P) is the point of maximum optical power output in the emission spectrum. Dominant Wavelength (λ_d) is derived from color coordinates and represents the single wavelength of pure spectral light that would be perceived as the same color by the human eye. λ_d is more relevant for color indication applications.

9.2 Why is there a current derating specification above 50°C?

LED lifetime and light output degrade with increasing junction temperature. The derating curve reduces the maximum allowable drive current as ambient temperature rises. This limits the internal power dissipation (heat) to keep the junction temperature within safe operating limits, ensuring long-term reliability.

9.3 Can I drive this LED with a voltage source without a current-limiting resistor?

No. An LED is a current-driven device. Connecting it directly to a voltage source exceeding its forward voltage will cause excessive current to flow, potentially destroying it instantly. A series resistor or constant-current driver is always required.

9.4 What does the \"Tolerance of each bin limit is ±15%\" mean?

It means the actual dividing line between intensity bins (e.g., between DE and FG) has a manufacturing tolerance of ±15%. A device measured at exactly 140 mcd, the nominal boundary, could be classified into either bin depending on test calibration and lot variation. Designers should use the minimum value of a bin for worst-case brightness calculations.

10. Practical Design and Usage Case Study

Scenario: Designing a status indicator panel for an industrial router. The panel requires a compact, dual-color (Red/Green) indicator for \"Power/Activity\" and \"System Fault.\"

Implementation:
1. The LTLR1DEKVJNNH155T is selected for its integrated right-angle holder (simplifies mounting behind a panel), bi-color capability (saves space), and black housing (provides good contrast).
2. The PCB layout includes three plated through-holes matching the device's lead spacing. The footprint is designed so the holder body sits flush against the PCB edge when bent.
3. A microcontroller GPIO pin drives each color via a simple transistor switch circuit. The current-limiting resistor is calculated as 150 Ohms for a 3.3V system drive ( (3.3V - 2.1V) / 0.008A ≈ 150 Ohms, using 8mA for reduced power and ample brightness).
4. During assembly, the leads are formed using a precision bending tool, ensuring the bend starts >2mm from the holder. The board is then wave soldered, adhering to the 5-second maximum dip time.
5. The final assembly shows a clean, professional indicator with bright, distinct red and green states visible from a wide angle.

11. Operational Principle

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons and holes recombine, releasing energy in the form of photons. The color of the emitted light is determined by the bandgap energy of the semiconductor material. This device uses Aluminum Indium Gallium Phosphide (AlInGaP) for both the red and green chips, a material system known for high efficiency in the red-to-yellow-green spectrum. The two chips are housed together under a single white diffused epoxy lens which scatters the light, creating a uniform appearance and widening the viewing angle.

12. Technology Trends and Context

Through-hole LED indicators like this one remain relevant in applications requiring high reliability, ease of manual assembly/service, or robust mechanical mounting. The trend in general LED technology continues towards higher efficiency (lumens per watt), improved color rendering, and miniaturization. For indicator applications, integration is a key trend—combining multiple colors, built-in control ICs (like flashing or RGB drivers), and smarter packaging. Environmentally, the move towards lead-free and RoHS-compliant manufacturing, as seen in this product, is now a global standard. The use of tape and reel packaging for through-hole components bridges traditional assembly methods with modern automated processes.