T1-3/4 Green LED Lamp Datasheet - 5mm Diameter - 4.0V Forward Voltage - 123mW Power Dissipation - English Technical Document

1. Product Overview

This document details the specifications for a high-efficiency, low-power consumption green LED lamp designed for through-hole mounting. The device utilizes InGaN (Indium Gallium Nitride) technology to produce a clear green light output. Its primary advantages include compatibility with integrated circuits due to low current requirements and versatile mounting options on printed circuit boards or panels. The popular T-1 3/4 package diameter (approximately 5mm) makes it a standard component suitable for a wide range of indicator and illumination applications in consumer electronics, instrumentation, and general-purpose signaling.

2. Technical Parameter Deep-Dive

2.1 Absolute Maximum Ratings

The device is rated for operation within strict environmental and electrical limits to ensure reliability and prevent damage. The maximum power dissipation is 123 mW at an ambient temperature (T_A) of 25°C. The DC forward current should not exceed 30 mA. For pulsed operation, a peak forward current of 100 mA is permissible under specific conditions: a 1/10 duty cycle and a pulse width of 0.1 ms. The operating temperature range is from -25°C to +80°C, while the storage temperature range extends from -30°C to +100°C. During soldering, leads can withstand 260°C for a maximum of 5 seconds, provided the soldering point is at least 1.6mm (0.063 inches) from the LED body.

2.2 Electrical & Optical Characteristics

Key performance parameters are measured at T_A=25°C. The luminous intensity (I_V) has a typical value of 8000 millicandelas (mcd) at a forward current (I_F) of 20 mA, with a minimum of 2500 mcd and a maximum of 18800 mcd. A ±15% tolerance applies to the guaranteed luminous intensity value. The viewing angle (2θ_1/2), defined as the off-axis angle where intensity drops to half its axial value, is 20 degrees. The dominant wavelength (λ_d) is 525 nm, placing it in the green spectrum, with a spectral line half-width (Δλ) of 35 nm. The forward voltage (V_F) is typically 4.0V with a maximum of 4.0V at I_F=20mA. The reverse current (I_R) is a maximum of 100 μA when a reverse voltage (V_R) of 5V is applied. It is critical to note that the device is not designed for reverse operation; this test condition is for characterization only.

3. Binning System Explanation

The luminous output of the LEDs is classified into bins to ensure consistency in applications. The bin code, marked on each packing bag, categorizes the minimum and maximum luminous intensity at 20mA. The bins range from T2 (2500-3390 mcd) to W2 (14110-18800 mcd). Each bin limit has a tolerance of ±15%. This system allows designers to select LEDs with the required brightness level for their specific application, ensuring visual uniformity when multiple LEDs are used together.

4. Performance Curve Analysis

While specific graphical data is referenced in the document (Typical Electrical/Optical Characteristics Curves on page 4), standard analysis for such components would include the Forward Current vs. Forward Voltage (I-V) curve, which shows the exponential relationship and helps in designing current-limiting circuits. The Luminous Intensity vs. Forward Current curve typically shows a near-linear relationship within the operating range. The Luminous Intensity vs. Ambient Temperature curve is crucial for understanding output degradation at higher temperatures. The spectral distribution curve would center around the 525 nm dominant wavelength with the specified 35 nm half-width.

5. Mechanical & Packaging Information

The LED features a standard T-1 3/4 round package with a water-clear lens. Key dimensional notes include: all dimensions are in millimeters (inches), with a general tolerance of ±0.25mm (.010") unless stated otherwise. The maximum protrusion of resin under the flange is 1.0mm (.04"). Lead spacing is measured at the point where the leads emerge from the package body. Correct mechanical handling is essential; leads must be formed at a point at least 3mm from the base of the LED lens before soldering and at normal temperature to avoid internal stress.

6. Soldering & Assembly Guidelines

Proper handling is critical for LED longevity. During soldering, a minimum clearance of 2mm must be maintained between the base of the lens and the soldering point. Dipping the lens into solder must be avoided. Do not reposition the LED after soldering. Avoid applying stress to the lead frame, especially when hot. For hand soldering, use an iron at a maximum temperature of 300°C for no more than 3 seconds (one time only). For wave soldering, pre-heat to a maximum of 100°C for up to 60 seconds, with the solder wave at a maximum of 260°C for up to 5 seconds. Infrared (IR) reflow is not suitable for this through-hole LED product. Excessive temperature or time can deform the lens or cause catastrophic failure.

7. Packaging & Ordering Information

The standard packaging configuration is as follows: 500 or 250 pieces per anti-static packing bag. Ten packing bags are placed in an inner carton, totaling 5000 pieces. Eight inner cartons are packed into an outer shipping carton, resulting in 40,000 pieces per outer carton. It is noted that in every shipping lot, only the final pack may not be a full pack.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is intended for ordinary electronic equipment including office automation devices, communication equipment, and household appliances. Its high efficiency and low power consumption make it ideal for status indicators, backlighting, and panel illumination where a clear green signal is required.

8.2 Design Considerations

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

9. Technical Comparison & Differentiation

Compared to older technology like GaP (Gallium Phosphide) green LEDs, this InGaN-based device offers significantly higher luminous intensity (thousands of mcd vs. hundreds of mcd) and a more saturated, pure green color (525 nm dominant wavelength). The 20-degree viewing angle provides a more focused beam compared to wide-angle LEDs, making it suitable for applications requiring directed light. The low current requirement (20mA for typical operation) maintains compatibility with common logic-level outputs from microcontrollers and driver ICs.

10. Frequently Asked Questions (FAQ)

Q: Can I drive this LED directly from a 5V supply?
A: No. With a typical forward voltage of 4.0V, connecting it directly to 5V would cause excessive current to flow, potentially destroying the LED. You must use a series current-limiting resistor. The resistor value can be calculated as R = (V_supply - V_F) / I_F. For a 5V supply and 20mA target current: R = (5V - 4.0V) / 0.020A = 50 Ohms. A standard 51 Ohm resistor would be suitable.

Q: Why is the reverse current specification important if the LED isn't for reverse operation?
A: The I_R spec indicates the quality of the semiconductor junction. A high reverse current can be a sign of damage or manufacturing defect. Furthermore, in circuit designs where reverse voltage transients might occur (e.g., from inductive loads), understanding this parameter helps in designing protective circuitry like parallel diodes to clamp reverse voltage.

Q: What does the \"Water Clear\" lens description mean?
A: \"Water Clear\" refers to an un-diffused, transparent lens. It does not contain diffusant particles. This results in the highest possible light output from the package but produces a more focused beam pattern (as seen in the 20-degree viewing angle) compared to a diffused or milky lens which spreads the light more evenly over a wider angle.

11. Practical Use Cases

Case 1: Multi-LED Status Panel: A control panel requires ten green status indicators. To ensure uniform brightness, each LED is driven by a separate output pin of a microcontroller via a 51-ohm series resistor (for a 5V MCU supply). The narrow 20-degree viewing angle ensures the light is clearly visible from the front of the panel without excessive side glare.

Case 2: Low-Battery Indicator: In a portable device, this LED, driven by a comparator circuit, provides a bright, attention-grabbing green light to indicate normal battery status. Its high efficiency minimizes the drain on the battery itself.

12. Operational Principle

Light is produced through a process called electroluminescence within the InGaN semiconductor material. When a forward voltage exceeding the device's turn-on threshold is applied across the anode and cathode, electrons are injected from the n-type region and holes from the p-type region into the active region. When electrons and holes recombine in this active region, energy is released in the form of photons (light). The specific composition of the Indium Gallium Nitride alloy determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, green at 525 nm.

13. Technology Trends

The use of InGaN materials for green LEDs represents a significant advancement over older technologies, offering higher efficiency and brightness. The industry trend continues towards increasing luminous efficacy (lumens per watt) and improving color consistency (tighter binning). For through-hole components, there is a general market shift towards surface-mount device (SMD) packages for automated assembly, but through-hole LEDs remain vital for prototyping, educational use, repair, and applications requiring higher mechanical robustness or heat dissipation via leads. Advances in packaging also focus on improving thermal management to maintain light output and longevity at higher operating currents and ambient temperatures.