LTL1DETBEK5 Through Hole LED Lamp Datasheet - T-1 Package - Blue/Red - 20mA - 3.4V/2.4V - English Technical Document

1. Product Overview

This document details the specifications for a through-hole LED lamp, identified by part number LTL1DETBEK5. The device is offered in two primary color variants: Blue and Red, utilizing InGaN and AlInGaP semiconductor technologies respectively. It is designed as a general-purpose status indicator lamp suitable for a wide range of electronic applications.

1.1 Core Features

• Low Power Consumption & High Efficiency: Designed for energy-efficient operation.
• Lead-Free & RoHS Compliant: Meets environmental regulations.
• Popular T-1 Diameter: Standard 5mm (T-1 3/4) package form factor for easy integration.
• Water Clear Lens: Provides high light output and pure color perception.

1.2 Target Applications

The LED is suitable for status indication across multiple industries, including:

• Communication Equipment
• Computer Peripherals and Systems
• Consumer Electronics
• Home Appliances

2. Mechanical & Package Information

The LED is housed in a standard radial leaded, T-1 (5mm) diameter package with a water-clear epoxy lens.

2.1 Outline Dimensions

Key dimensional notes (all in mm, inches in parentheses):

• Standard T-1 package diameter.
• Lead spacing is measured where leads emerge from the package body.
• Tolerance is typically ±0.25mm (±0.010\") unless otherwise specified.
• Maximum resin protrusion under the flange is 1.0mm (0.04\").

Note: Specifications are subject to change without notice.

3. Absolute Maximum Ratings

Ratings at an ambient temperature (TA) of 25°C. Exceeding these limits may cause permanent damage.

4. Electrical & Optical Characteristics

Typical characteristics measured at TA=25°C and IF=20mA, unless otherwise noted.

4.1 Characteristic Notes

1. Luminous Intensity Measurement: Measured with a sensor/filter approximating the CIE photopic eye-response curve.
2. Viewing Angle (2θ1/2): The off-axis angle where intensity is half the axial (on-axis) intensity.
3. Dominant Wavelength (λd): Derived from the CIE chromaticity diagram, representing the perceived single wavelength of the color.
4. Intensity Tolerance: Iv specifications include a ±30% testing tolerance.
5. Reverse Operation: The device is not designed for reverse bias operation. The VR=5V condition is for IR testing only.

5. Binning System Specification

The LEDs are sorted into bins based on luminous intensity at 20mA. This ensures consistency in brightness for production applications.

5.1 Luminous Intensity Bins

Note: Tolerance on each bin limit is ±15%.

6. Packaging Specification

The standard packaging flow is as follows:

• Base Unit: 500, 200, or 100 pieces per anti-static packing bag.
• Inner Carton: 10 packing bags are placed into one inner carton, totaling 5,000 pieces.
• Outer Carton (Shipping): 8 inner cartons are packed into one outer carton, totaling 40,000 pieces.
• In every shipping lot, only the final pack may be a non-full pack.

7. Application & Handling Guidelines

7.1 Recommended Application

Suitable for indoor/outdoor signage and general electronic equipment status indication.

7.2 Storage Conditions

• Do not exceed 30°C or 70% relative humidity.
• LEDs removed from original packaging should be used within three months.
• For extended storage outside original packaging, use a sealed container with desiccant or a nitrogen ambient.

7.3 Cleaning

Use alcohol-based solvents like isopropyl alcohol if cleaning is necessary.

7.4 Lead Forming & PCB Assembly

• Bending Point: Bend leads at a point at least 3mm from the base of the LED lens. Do not use the package base as a fulcrum.
• Sequence: Perform lead forming at room temperature before soldering.
• Assembly: Use minimum clinch force on PCB to avoid mechanical stress on the LED body.

7.5 Soldering Instructions

Critical Rule: Maintain a minimum clearance of 2mm from the base of the lens to the solder point. Do not immerse the lens in solder.

Recommended Conditions:

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

7.6 Drive Circuit Design

LEDs are current-operated devices. For uniform brightness when using multiple LEDs:

• Recommended (Circuit A): Use a current-limiting resistor in series with each LED. This compensates for variations in the forward voltage (Vf) of individual LEDs.
• Not Recommended (Circuit B): Connecting multiple LEDs directly in parallel without individual resistors is discouraged. Small differences in I-V characteristics can lead to significant differences in current sharing and, therefore, brightness.

The series resistor value (R) can be calculated using Ohm's Law: R = (Vsupply - Vf_LED) / Idesired, where Vf_LED is the typical forward voltage from the datasheet and Idesired is the target drive current (e.g., 20mA).

7.7 ESD (Electrostatic Discharge) Precautions

These LEDs are susceptible to damage from static electricity.

• Personal Grounding: Use a conductive wrist strap or anti-static gloves when handling.
• Equipment Grounding: Ensure all workstations, tools, and storage racks are properly grounded.
• Charge Neutralization: Use an ionizer to neutralize static charge that may build up on the plastic lens.
• Training: Personnel working in ESD-sensitive areas should be properly trained and certified.

8. Performance Curve Analysis & Design Considerations

8.1 Forward Voltage (Vf) vs. Forward Current (If)

The typical curves show the exponential relationship between voltage and current for both blue and red LEDs. The blue LED (InGaN) has a higher typical Vf (~3.4V) compared to the red LED (AlInGaP, ~2.4V) at 20mA. Designers must account for this difference when calculating series resistor values or designing power supplies for multi-color applications.

8.2 Luminous Intensity vs. Forward Current

Intensity is approximately proportional to forward current in the normal operating range. Driving the LED above the recommended DC current (30mA) will increase light output but also increase power dissipation and junction temperature, potentially reducing lifetime and causing color shift.

8.3 Thermal Considerations

While the document provides maximum ratings, it's important to understand that LED performance degrades with increasing junction temperature. For the red AlInGaP LED, luminous efficiency typically decreases more significantly with temperature rise compared to the blue InGaN LED. In high-ambient-temperature environments or high-current drive scenarios, thermal management (e.g., PCB copper area) should be considered to maintain performance and reliability.

8.4 Viewing Angle and Optical Design

The 30-degree half-angle provides a reasonably wide viewing cone suitable for panel indicators. For applications requiring a very narrow beam, secondary optics (e.g., lenses) would be necessary. The water-clear lens is optimal for the purest color output but offers no diffusion; for a softer, more uniform appearance, a diffused lens variant would be required.

9. Technical Comparison & Selection Guidance

9.1 Blue vs. Red Variant Summary

9.2 Common Design Questions

Q: Can I drive this LED directly from a 5V digital logic pin?
A: No. The typical Vf is 2.4V (Red) or 3.4V (Blue). A series resistor is always required to limit the current. For a 5V supply and 20mA target: R_red ≈ (5V - 2.4V) / 0.02A = 130Ω; R_blue ≈ (5V - 3.4V) / 0.02A = 80Ω. Use the nearest standard higher value for safety.

Q: Why is the reverse current (IR) rating important if reverse operation is not allowed?
A> It is a quality and leakage test parameter. A high reverse leakage current can indicate a damaged or defective junction.

Q: How do I select the right intensity bin?
A> Choose based on application brightness requirements and required consistency. For a panel of multiple LEDs, specifying a single, tighter bin (e.g., KL for blue) ensures uniform appearance. For a single indicator, a wider bin may be acceptable for cost savings.

10. Practical Application Examples

10.1 Power-On Indicator for a 12V Device

Goal: Indicate device is powered using a red LED.
Design: Supply voltage = 12V. Target current = 15mA (for longer life).
Calculation: Vf_red_typ = 2.4V. Resistor value R = (12V - 2.4V) / 0.015A = 640Ω. Power in resistor P_R = (12V-2.4V)*0.015A = 0.144W. Use a standard 620Ω or 680Ω, 1/4W resistor.

10.2 Dual-Color Status Indicator (Microcontroller Driven)

Goal: Use one blue and one red LED to show different statuses (e.g., standby/active) controlled by MCU GPIO pins.
Design: MCU VDD = 3.3V. Drive LEDs at 10mA for lower power.
Calculation:
- Blue: R = (3.3V - 3.4V) / 0.01A = -10Ω (Invalid). This shows a problem: the typical Vf of the blue LED (3.4V) is higher than the supply (3.3V). The blue LED may not light, or will be very dim. Solution: Use a blue LED with a lower Vf bin, reduce current further, or use a charge pump/boost circuit.
- Red: R = (3.3V - 2.4V) / 0.01A = 90Ω. This works well.
This example highlights the importance of checking supply voltage against LED Vf.