LTL17KRL6D Red LED Lamp Datasheet - T-1 (3mm) Diameter - 2.0V Forward Voltage - 75mW Power - English Technical Document

1. Product Overview

The LTL17KRL6D is a standard through-hole LED lamp designed for status indication and signaling applications. It features a popular T-1 (3mm) diameter package with a red, diffused lens. This device is characterized by low power consumption, high luminous efficiency, and is compliant with RoHS directives, making it a lead-free component suitable for modern electronic designs.

1.1 Core Advantages

• High Efficiency: Delivers high luminous intensity output relative to its power consumption.
• Design Flexibility: Available in standard T-1 package, compatible with common PCB layouts.
• Environmental Compliance: Manufactured as a lead-free product, adhering to RoHS standards.
• Reliability: Designed for stable operation across a wide temperature range.

1.2 Target Applications

This LED is versatile and finds use in numerous sectors requiring reliable visual indicators. Primary application areas include communication equipment, computer peripherals, consumer electronics, home appliances, and various industrial control systems.

2. Technical Parameter Analysis

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 (P_D): 75 mW
• DC Forward Current (I_F): 30 mA
• Peak Forward Current (I_FP): 90 mA (Pulse conditions: Duty Cycle ≤ 1/10, Pulse Width ≤ 10μs)
• 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 for a maximum of 5 seconds, measured 2.0mm from the LED body.

2.2 Electrical & Optical Characteristics

These parameters are measured at an ambient temperature (T_A) of 25°C and define the typical performance of the device.

• Luminous Intensity (I_V): 310 mcd (Min), 460 mcd (Typ), 680 mcd (Max) at I_F = 20mA. Measured with a filter approximating the CIE photopic eye response.
• Viewing Angle (2θ_1/2): 60 degrees (Typical). Defined as the off-axis angle where intensity is half the axial value.
• Peak Wavelength (λ_P): 631 nm (Typical).
• Dominant Wavelength (λ_d): 617 nm (Min), 627 nm (Typ), 637 nm (Max). This defines the perceived color.
• Spectral Half-Width (Δλ): 20 nm (Typical).
• Forward Voltage (V_F): 2.0 V (Typ), 2.4 V (Max) at I_F = 20mA.
• Reverse Current (I_R): 100 μA (Max) at V_R = 5V. Note: The LED is not designed for reverse bias operation.

3. Binning System Specification

The LTL17KRL6D is classified into bins based on luminous intensity and dominant wavelength to ensure color and brightness consistency in production applications.

3.1 Luminous Intensity Binning

Binning is performed at a test current of 20mA. Each bin has a tolerance of ±15% on its limits.

• Bin K: 310 mcd (Min) to 400 mcd (Max)
• Bin L: 400 mcd (Min) to 520 mcd (Max)
• Bin M: 520 mcd (Min) to 680 mcd (Max)

3.2 Dominant Wavelength Binning

Binning ensures color uniformity. 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
• Bin H31: 629.0 nm to 633.0 nm
• Bin H32: 633.0 nm to 637.0 nm

4. Mechanical & Packaging Information

4.1 Outline Dimensions

The LED conforms to the standard T-1 (3mm) radial leaded package. Key dimensional notes include: all dimensions are in millimeters; tolerance is ±0.25mm unless specified; maximum resin protrusion under the flange is 1.0mm; lead spacing is measured at the point where leads exit the package.

4.2 Packaging Specification

The LEDs are supplied in anti-static packing bags. Standard packing quantities are 1000, 500, 200, or 100 pieces per bag. These are then consolidated into inner and outer cartons for bulk shipment.

• Inner Carton: Contains 10 packing bags, totaling 10,000 pieces.
• Outer Carton: Contains 8 inner cartons, totaling 80,000 pieces. The last pack in a shipping lot may not be a full pack.

5. Assembly & Handling Guidelines

5.1 Storage Conditions

For optimal shelf life, LEDs should be stored in an environment not exceeding 30°C and 70% relative humidity. Components removed from their original packaging should be used within three months. For longer storage outside the original bag, use a sealed container with desiccant or a nitrogen-filled desiccator.

5.2 Lead Forming & PCB Assembly

• Bend leads at a point at least 3mm from the base of the LED lens. Do not use the lens base as a fulcrum.
• Lead forming must be completed before soldering and at room temperature.
• During PCB insertion, apply the minimum clinch force necessary to avoid imposing excessive mechanical stress on the component.

5.3 Soldering Recommendations

Maintain a minimum distance of 2mm from the base of the lens to the solder point. Avoid immersing the lens in solder. Do not apply stress to the leads while the LED is hot.

• Soldering Iron: Maximum temperature 350°C for a maximum of 3 seconds (one time only).
• Wave Soldering: Pre-heat to a maximum of 100°C for up to 60 seconds. Solder wave temperature maximum 260°C for up to 5 seconds.
• Important: Excessive temperature or time can deform the lens or cause failure. IR reflow soldering is NOT suitable for this through-hole LED.

5.4 Cleaning

If cleaning is necessary, use alcohol-based solvents such as isopropyl alcohol.

6. Application & Circuit Design

6.1 Drive Circuit Design

LEDs are current-operated devices. To ensure uniform brightness when driving multiple LEDs, it is strongly recommended to use a current-limiting resistor in series with each LED (Circuit A). Connecting LEDs directly in parallel (Circuit B) is not advised, as slight variations in the forward voltage (V_F) characteristic between individual LEDs will cause significant differences in current sharing and, consequently, perceived brightness.

6.2 Electrostatic Discharge (ESD) Protection

LEDs are sensitive to electrostatic discharge. Implement the following ESD control measures in the handling and assembly area:

• Operators must wear grounded wrist straps or anti-static gloves.
• All equipment, workstations, and storage racks must be properly grounded.
• Use ionizers to neutralize static charge that may accumulate on the plastic lens.
• Maintain a static-safe work area with all surfaces measuring less than 100V.

7. Performance Curves & Thermal Considerations

While specific graphs are referenced in the datasheet (e.g., Typical Characteristics Curves), the provided electrical parameters allow for key performance estimations. The forward voltage has a negative temperature coefficient, meaning V_F will decrease slightly as the junction temperature increases. The luminous output is also temperature-dependent, typically decreasing as temperature rises. Designers should consider thermal management if operating near maximum ratings or in high ambient temperatures to maintain long-term reliability and consistent light output.

8. Frequently Asked Questions (FAQ)

8.1 Can I drive this LED without a series resistor?

No. Operating an LED directly from a voltage source is not recommended and will likely destroy the device due to overcurrent. A series resistor is mandatory to limit the current to the specified value (e.g., 20mA for typical brightness).

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

Peak Wavelength (λ_P): The wavelength at which the optical output power is maximum. Dominant Wavelength (λ_d): The single wavelength perceived by the human eye, calculated from the CIE chromaticity coordinates. λ_d is more relevant for color definition in indication applications.

8.3 Is this LED suitable for outdoor use?

The datasheet lists applications including outdoor signs. However, the operating temperature range is -40°C to +85°C. For harsh outdoor environments, consider additional protection against moisture, UV radiation, and thermal cycling, which may not be provided by the LED package alone.

8.4 How do I interpret the bin codes when ordering?

Specify the required Luminous Intensity Bin (K, L, M) and Dominant Wavelength Bin (H28 to H32) to ensure you receive LEDs with consistent brightness and color. If not specified, you may receive components from any production bin within the product's overall specification range.

9. Design Considerations & Best Practices

• Current Selection: For longest lifetime, operate below the absolute maximum DC current of 30mA. The typical test condition of 20mA is a good balance of brightness and reliability.
• Heat Dissipation: Although power dissipation is low, ensure adequate spacing on the PCB and avoid enclosing the LED in a way that traps heat, especially when operating at high ambient temperatures.
• Polarity: The longer lead is typically the anode (+). Always verify polarity before soldering to prevent reverse bias application.
• Optical Design: The 60-degree viewing angle provides a wide beam. For more focused light, external lenses or light pipes may be required.