LED Lamp T1 3mm & T1 3/4 5mm Through Hole - Hyper Red to Green - 20mA 2.4V - English Datasheet

1. Product Overview

This document details a family of general-purpose LED lamps available in two industry-standard through-hole package sizes: T1 (3mm) and T1 3/4 (5mm). These devices are engineered to deliver higher luminous intensity levels compared to basic indicator LEDs, making them suitable for applications requiring enhanced visibility. The core light-emitting material is Aluminum Indium Gallium Phosphide (AlInGaP) grown on a Gallium Arsenide substrate, a technology known for its high efficiency and good color purity across the red to green spectrum.

1.1 Core Advantages

The primary benefits of this LED series include low power consumption, high luminous intensity output, and high efficiency. They are offered with a variety of lens tint options corresponding to different source colors, providing design flexibility. The standard 45-degree viewing angle ensures a broad and consistent light emission pattern.

1.2 Target Applications

These LEDs are designed for general-purpose indicator lights and status displays across a wide range of consumer electronics, industrial control panels, automotive interior lighting, and appliance indicators where reliable, bright signaling is required.

2. Technical Parameter Deep Dive

The following sections provide a detailed, objective analysis of the key technical parameters specified in the datasheet.

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the stress limits beyond which permanent damage to the device may occur. For all color variants in this series, the continuous forward current is rated at 30 mA at an ambient temperature (T_A) of 25°C. The power dissipation is 75 mW. A peak forward current of 90 mA (for red variants) or 60 mA (for amber, yellow, green variants) is permissible under pulsed conditions (1/10 duty cycle, 0.1ms pulse width). The maximum reverse voltage is 5V. The operating and storage temperature range is specified from -40°C to +100°C. The derating factor for forward current is 0.4 mA/°C linearly from 70°C, meaning the allowable continuous current decreases as temperature rises above this point to prevent overheating.

2.2 Electrical & Optical Characteristics

The electrical and optical characteristics are measured at T_A=25°C with a standard test current (I_F) of 20 mA. The data is presented separately for the 3mm (F Series, part numbers starting with LTL1CHJ) and 5mm (H Series, part numbers starting with LTL2F7J) packages, but the values are identical for equivalent colors.

2.2.1 Luminous Intensity (I_v)

The luminous intensity, a measure of perceived brightness, has a minimum specified value of 65 mcd for all color types. Typical values vary by color: Hyper Red (LTLxCHJDTNN/xF7JDTNN) is 120 mcd, Super Red (LTLxCHJRTNN/xF7JRTNN) is 140 mcd, while Red, Amber, Yellow, and Green variants (LTLxCHJETNN/FTNN/YTNN/STNN/GTNN) have a typical intensity of 180 mcd. The products support a two-rank classification system for luminous intensity, with the specific rank code marked on the packaging.

2.2.2 Wavelength Parameters

Three key wavelength parameters define the color output:

• Peak Emission Wavelength (λ_P): The wavelength at which the spectral power distribution is maximum. It ranges from 650 nm (Hyper Red) down to 575 nm (Green).
• Dominant Wavelength (λ_d): Derived from the CIE chromaticity diagram, this represents the single wavelength that best defines the perceived color of the LED. It is generally slightly shorter than the peak wavelength for these devices, e.g., 639 nm for Hyper Red, 624 nm for Red, 605 nm for Amber, down to 572 nm for Green.
• Spectral Line Half-Width (Δλ): The full width at half maximum (FWHM) of the emission spectrum, indicating color purity. It is 20 nm for red variants, 17 nm for amber, and 15 nm for yellow and green variants.

2.2.3 Electrical Parameters

The forward voltage (V_F) at I_F=20 mA has a maximum rating between 2.3V and 2.4V depending on the color, with typical values around 2.0V to 2.05V. The reverse current (I_R) is guaranteed to be 100 μA maximum at a reverse voltage (V_R) of 5V. The junction capacitance (C) is typically 40 pF when measured at 0V bias and 1 MHz frequency.

2.2.4 Viewing Angle

The viewing angle, defined as 2θ_1/2 (twice the half-angle), is 45 degrees. θ_1/2 is the off-axis angle where the luminous intensity drops to half of its axial (on-center) value. This creates a medium-width beam suitable for general indication.

3. Binning System Explanation

The datasheet indicates the use of a binning system primarily for luminous intensity. Products are classified into two intensity ranks. The specific rank code (Iv classification code) is marked on each individual packing bag. This allows designers to select LEDs with consistent brightness levels for their applications. While not explicitly detailed for wavelength or forward voltage in this document, typical manufacturing processes for such LEDs often include bins for dominant wavelength and V_F to ensure color and electrical consistency.

4. Performance Curve Analysis

The datasheet references typical electrical/optical characteristic curves on the final page. While the specific graphs are not provided in the text content, standard curves for such LEDs would typically include:

• Forward Current vs. Forward Voltage (I-V Curve): Shows the exponential relationship, crucial for designing current-limiting circuits.
• Luminous Intensity vs. Forward Current: Demonstrates how brightness increases with current, up to the maximum rated limits.
• Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as the operating temperature increases.
• Spectral Power Distribution: A plot of relative intensity versus wavelength, showing the peak and shape of the emission spectrum for each color.

5. Mechanical & Package Information

5.1 Package Dimensions

Detailed dimensioned drawings are provided for both the T1 (LTL1CHx Series) and T1 3/4 (LTL2F7x Series) packages. Key dimensions include the body diameter (approx. 3mm and 5mm respectively), total height, and lead spacing. The leads are measured where they emerge from the package body. A maximum protrusion of resin under the flange of 1.0mm is noted. All dimensions are in millimeters with a standard tolerance of ±0.25mm unless otherwise specified.

5.2 Polarity Identification

For through-hole LEDs, polarity is typically indicated by two features: the longer lead denotes the anode (positive), and the flat side on the LED lens rim or a notch on the plastic flange often denotes the cathode (negative) side. The specific marking should be verified on the package diagram.

6. Soldering & Assembly Guidelines

The datasheet specifies a lead soldering temperature of 260°C for a maximum duration of 5 seconds, measured at a distance of 1.6mm (0.063") from the LED body. This is a critical parameter to prevent thermal damage to the internal semiconductor die and the epoxy lens. When using wave or hand soldering, care must be taken to adhere to this time-temperature profile. It is recommended to use a heat sink (e.g., tweezers) on the lead between the solder point and the LED body if prolonged heat is expected.

7. Packaging & Ordering Information

7.1 Part Numbering Rule

The part number follows the structure: LTL [Series Code] [Color/Intensity Code] TNN.

• LTL: Product family prefix.
• Series Code: 1CHJ for 3mm (F Series), 2F7J for 5mm (H Series).
• Color Code: The letter before \"TNN\" indicates color and type (e.g., D for Hyper Red, R for Super Red, E for Red, F for Amber, Y for Amber Yellow, S for Yellow, G for Green).
• TNN: Common suffix for this series.

7.2 Packing Specification

The luminous intensity rank code (Iv classification) is marked on each packing bag. Standard packaging for such components is typically on tape and reel or in bulk bags, though the specific quantities are not detailed in this excerpt.

8. Application Recommendations

8.1 Typical Application Circuits

These LEDs require a current-limiting resistor in series when connected to a voltage source. The resistor value can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F. Using the maximum V_F from the datasheet in this calculation ensures the current does not exceed the desired value even with device-to-device variation. For a 5V supply and a typical Red LED (V_F ~2.4V max) at 20mA, the resistor would be R = (5 - 2.4) / 0.02 = 130 Ω. A standard 130Ω or 150Ω resistor would be appropriate.

8.2 Design Considerations

• Current Drive: Always drive LEDs with a controlled current, not a fixed voltage. Use a series resistor or constant current driver.
• Thermal Management: While power dissipation is low, operating at high ambient temperatures (near 100°C) requires derating the forward current as per the 0.4 mA/°C guideline above 70°C.
• Reverse Voltage Protection: The maximum reverse voltage is only 5V. If there is any possibility of reverse bias in the circuit (e.g., in AC or multiplexed applications), an external protection diode should be used.
• Viewing Angle: The 45-degree viewing angle provides a wide beam. For more directional light, secondary optics may be required.

9. Technical Comparison & Differentiation

Compared to older technology LEDs like Gallium Phosphide (GaP), these AlInGaP-based LEDs offer significantly higher luminous efficiency, resulting in brighter output at the same current. The variety of precise colors within the red-orange-yellow-green spectrum, each with defined wavelength and purity, allows for accurate color signaling and display. The availability in two common package sizes (3mm and 5mm) provides direct drop-in compatibility with a vast array of existing PCB footprints and panel cut-outs.

10. Frequently Asked Questions (FAQs)

Q: What is the difference between Peak Wavelength and Dominant Wavelength?
A: Peak wavelength is the physical peak of the light emitted. Dominant wavelength is the perceived color point on the CIE chart. For LEDs, especially with broad spectra, they can differ. Dominant wavelength is more relevant for color matching.

Q: Can I drive this LED at 30mA continuously?
A: Yes, 30mA is the maximum continuous DC current rating at 25°C. However, if the ambient temperature exceeds 70°C, the current must be reduced according to the derating factor (0.4 mA/°C) to avoid exceeding the maximum junction temperature.

Q: The lens is described as \"Transparent\". Why are there different colors?
A: The lens material itself is clear epoxy. The color is determined by the semiconductor material (AlInGaP) which emits colored light, and sometimes by additional dopants or conversion materials in the encapsulation. The \"tinted lens\" option refers to the color of the emitted light, not a colored filter.

Q: How do I identify the anode and cathode?
A: The longer lead is the anode (+). Visually, looking at the LED from the top, the flat side on the rim of the lens or the flange typically corresponds to the cathode (-). Always refer to the package drawing for the definitive marking.

11. Practical Use Case

Scenario: Designing a multi-status indicator panel for an industrial controller. The panel requires distinct, bright colors for \"Power On\" (Green), \"Standby\" (Amber), \"Fault\" (Red), and \"Communication Active\" (Flashing Yellow). This LED series is ideal. The designer would select the LTLxCHJGTNN (Green), LTLxCHJFTNN (Amber), LTLxCHJETNN (Red), and LTLxCHJSTNN (Yellow). Using a common 20mA drive current simplifies the driver circuit design (a microcontroller with current-limiting resistors). The 45-degree viewing angle ensures the indicators are visible from a wide range of operator positions. The high luminous intensity (65-180 mcd) guarantees visibility even in well-lit industrial environments.

12. Technology Principle Introduction

These LEDs are based on Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material grown epitaxially on a Gallium Arsenide (GaAs) substrate. When a forward voltage is applied across the p-n junction, electrons and holes are injected into the active region where they recombine. This recombination process releases energy in the form of photons (light). The specific bandgap energy of the AlInGaP alloy, which can be tuned by varying the ratios of Aluminum, Indium, Gallium, and Phosphorus, determines the wavelength (color) of the emitted light. This material system is particularly efficient for producing high-brightness light in the red, orange, amber, and yellow-green portions of the visible spectrum.

13. Technology Development Trends

The general trend in LED technology is towards higher efficiency (more lumens per watt), increased reliability, and lower cost. For through-hole indicator LEDs like these, development often focuses on refining the epitaxial growth process to yield even higher luminous intensity from the same chip size and current, and improving the plastic encapsulation materials for better thermal stability and color consistency over long lifetimes. While surface-mount device (SMD) packages dominate new designs for miniaturization, through-hole LEDs remain vital for prototyping, repair, legacy systems, and applications requiring robust mechanical mounting or higher single-point brightness from a discrete component.