Oval LED Lamp 3474BFGR/MS Datasheet - Oval Shape - 20mA Forward Current - Brilliant Green Color - English Technical Document

1. Product Overview

This document provides the complete technical specifications for the 3474BFGR/MS Oval LED Lamp. This component is a precision optical performance LED specifically engineered for applications requiring clear, defined illumination patterns, such as passenger information systems and commercial signage.

1.1 Core Features and Advantages

The primary advantages of this oval LED lamp stem from its unique design and performance characteristics:

• High Luminous Intensity Output: Delivers bright, consistent light output suitable for daylight-readable signs.
• Oval Shape with Defined Radiation Pattern: The oval lens creates a matched radiation pattern ideal for mixing with yellow, blue, or red colors in multi-color sign applications, ensuring uniform appearance.
• Wide and Asymmetric Viewing Angle: Features a 2θ1/2 viewing angle of 110° in the X-axis and 60° in the Y-axis, providing a broad horizontal coverage suitable for viewing from various angles while controlling vertical spread.
• Robust Environmental Compliance: The device is constructed with UV-resistant epoxy and complies with key environmental standards including RoHS, EU REACH, and is Halogen-free (Br <900 ppm, Cl <900 ppm, Br+Cl <1500 ppm).
• Application-Specific Design: Optimized for integration into color graphic signs, message boards, variable message signs (VMS), and commercial outdoor advertising displays.

2. Technical Parameters and Specifications

2.1 Device Selection and Absolute Maximum Ratings

The LED utilizes an InGaN (Indium Gallium Nitride) chip material to produce a Brilliant Green color, diffused through a green lens. Operating limits must not be exceeded to ensure reliability.

2.2 Electro-Optical Characteristics

All parameters are measured at an ambient temperature (T_a) of 25°C and a standard forward current (I_F) of 20mA, unless otherwise specified.

3. Binning System Explanation

To ensure consistency in brightness and color for large-scale applications, the LEDs are sorted into bins based on luminous intensity and dominant wavelength.

3.1 Luminous Intensity Binning

LEDs are categorized into four bins (GA, GB, GC, GD) with a ±10% tolerance on the nominal luminous intensity value.

3.2 Dominant Wavelength Binning

Color consistency is controlled through five wavelength bins (G1 to G5) with a tight tolerance of ±1nm.

4. Performance Curve Analysis

The datasheet includes several key performance graphs that illustrate the LED's behavior under different conditions. These are critical for robust system design.

4.1 Spectral and Angular Characteristics

The Relative Intensity vs. Wavelength curve shows a typical peak around 522nm, confirming the brilliant green color output. The Directivity plot visually represents the asymmetric 110° x 60° viewing angle, crucial for understanding the spatial light distribution in the final application.

4.2 Electrical and Thermal Behavior

The Forward Current vs. Forward Voltage (I-V Curve) is essential for driver design, showing the typical exponential relationship. The Relative Intensity vs. Forward Current curve demonstrates how light output increases with current, important for brightness tuning. The Relative Intensity vs. Ambient Temperature and Forward Current vs. Ambient Temperature graphs highlight thermal performance. Light output decreases as temperature rises, a key consideration for thermal management in enclosed signs or high-ambient environments.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED features a standard oval lamp package with two leads. Critical dimensional notes include: all unspecified dimensions are in millimeters with a standard tolerance of ±0.25mm, and the maximum protrusion of resin under the flange is 1.5mm. Designers must refer to the detailed dimensioned drawing in the original datasheet for precise PCB footprint and mechanical clearance planning.

5.2 Moisture Resistant Packing and Labeling

The components are supplied in moisture-resistant packing to prevent damage during storage and transit. They are housed on carrier tapes, which are then placed in inner and outer cartons. The packing specification is 2500 pieces per inner carton and 10 inner cartons per outside carton (25,000 pieces total). The reel label contains vital information for traceability and correct application, including Customer's Product Number (CPN), Product Number (P/N), Packing Quantity (QTY), and the specific Binning codes for Luminous Intensity (CAT), Dominant Wavelength (HUE), and Forward Voltage (REF).

6. Assembly, Handling, and Storage Guidelines

6.1 Lead Forming and Soldering

• Lead Forming: Must be performed before soldering. Bends should be made at least 3mm from the epoxy bulb base to avoid stress on the package. Cutting should be done at room temperature.
• PCB Mounting: PCB holes must align perfectly with LED leads. Misalignment causing stress on the leads can degrade the epoxy and LED performance.
• Soldering: The solder joint must be more than 3mm from the epoxy bulb. Wave or reflow soldering at 260°C should not exceed 5 seconds.

6.2 Storage Conditions

For long-term reliability, LEDs should be stored at ≤30°C and ≤70% Relative Humidity. The recommended storage life after shipment is 3 months. For storage beyond 3 months and up to one year, the components should be kept in a sealed container with a nitrogen atmosphere and moisture-absorbent material. Rapid temperature changes in humid environments must be avoided to prevent condensation.

7. Application Notes and Design Considerations

7.1 Typical Application Scenarios

This LED is expressly designed for passenger information signs, variable message signs (VMS) on highways, commercial outdoor advertising boards, and general message displays. Its oval beam pattern and high intensity make it ideal for these applications where readability from a distance and wide horizontal viewing angles are paramount.

7.2 Design and Implementation Advice

• Current Limiting: Always use a series current-limiting resistor or a constant-current driver to maintain the forward current at or below the rated 20mA. Exceeding this value reduces lifespan.
• Thermal Management: Although power dissipation is low, consider the operating environment. In enclosed signs or high ambient temperatures, ensure adequate ventilation to prevent excessive junction temperature rise, which reduces light output.
• Optical Integration: The asymmetric beam (110°x60°) is designed to mix with other colors. When designing multi-color pixel clusters, account for this pattern to achieve uniform color blending across the viewing area.
• Binning for Consistency: For large display projects, specifying tight bins (e.g., GD for highest brightness, G3 for specific green hue) is crucial to avoid visible brightness or color variations across the sign.

8. Technical Comparison and Differentiation

The primary differentiating factor of this LED is its oval lens geometry, which is not common in standard round LEDs. This shape provides a tailored radiation pattern that is inherently more suitable for rectangular pixels in signage, potentially reducing optical losses and improving efficiency compared to using a diffuser over a standard round LED. Its combination of high luminous intensity (up to 5760 mcd) and a specifically wide horizontal viewing angle targets a niche in the high-brightness display market, setting it apart from general-purpose indicator LEDs.

9. Frequently Asked Questions (FAQ)

9.1 What is the purpose of the oval shape?

The oval shape creates an asymmetric radiation pattern (110° wide, 60° tall) that naturally fits the rectangular format of most information signs and pixels, providing efficient, uniform illumination without wasted light.

9.2 How do I interpret the luminous intensity bin codes (GA, GB, etc.)?

These codes represent sorted groups based on measured brightness at 20mA. GA is the dimmest group (2781-3335 mcd), and GD is the brightest (4800-5760 mcd). Specifying a bin ensures consistency across a large installation.

9.3 Can I drive this LED with a voltage source?

No. LEDs are current-driven devices. Applying a voltage directly will cause current to rise uncontrollably (due to the diode's exponential I-V curve), likely destroying the LED. Always use a current-limiting mechanism.

9.4 What is the difference between Peak Wavelength (522nm) and Dominant Wavelength (528nm typ.)?

Peak Wavelength is the single wavelength where the spectral power is highest. Dominant Wavelength is the perceived color of the light, calculated from the entire spectrum. The human eye's sensitivity affects this value, making dominant wavelength more relevant for color specification.

10. Practical Use Case Example

Scenario: Designing a Highway Variable Message Sign (VMS)
An engineer is designing a full-color VMS panel. Each pixel comprises red, green, and blue sub-pixels. For the green sub-pixel, the 3474BFGR/MS is selected.
Implementation: The LEDs are arranged on a PCB in a matrix. A constant-current driver IC supplies 20mA to each LED string. The oval beam pattern of the green LED is aligned so its 110° wide axis corresponds to the horizontal direction of the highway, ensuring good visibility for drivers across multiple lanes. The 60° vertical axis contains the beam to avoid light pollution. To ensure color and brightness uniformity across the large sign, the procurement order specifies bins GC for luminous intensity and G3 for dominant wavelength. Proper heat sinking on the metal backplane of the sign maintains ambient temperature within limits, preserving LED output and longevity.

11. Operational Principle

This LED operates on the principle of electroluminescence in a semiconductor. When a forward voltage is applied across the InGaN (Indium Gallium Nitride) p-n junction, electrons and holes recombine, releasing energy in the form of photons. The specific composition of the InGaN alloy determines the bandgap energy, which in turn defines the wavelength of the emitted light—in this case, in the green spectrum (~522-535nm). The epoxy lens encapsulates the chip, provides mechanical protection, and is shaped (oval) to control the radiation pattern of the emitted light.

12. Industry Trends and Context

LEDs for signage and professional displays represent a specialized segment of the broader LED market. Trends include:
Increased Efficiency: Ongoing development aims for higher luminous efficacy (more light output per electrical watt), allowing for brighter displays or lower power consumption.
Enhanced Color Gamut: Improvements in phosphor and chip technology enable wider color gamuts for more vivid and accurate displays.
Miniaturization and Density: There is a constant drive towards smaller pixel pitches for higher-resolution displays, requiring LEDs with smaller footprints and precise optical control.
Intelligent Drivers: Integration of control electronics closer to the LED (e.g., COB - Chip-on-Board with integrated drivers) for smarter, addressable display modules. While this specific datasheet describes a discrete, through-hole component, the underlying performance requirements (intensity, viewing angle, color) remain fundamental to all signage LEDs, regardless of packaging evolution.