SMD LED 19-137/R6GHBHC-A01/2T Datasheet - Multi-Color - 20mA - English Technical Document

1. Product Overview

The 19-137 series is a compact, surface-mount LED designed for high-density applications. Its small form factor enables significant reductions in board size and equipment footprint. The series is available in multiple colors (brilliant red, green, and blue) using different semiconductor materials, offering design flexibility for various indicator and backlighting needs.

1.1 Core Advantages

• Miniaturization: Significantly smaller than lead-frame type LEDs, allowing for higher packing density and smaller end products.
• Lightweight: Ideal for miniature and portable applications.
• Compatibility: Packaged in 8mm tape on 7-inch reels for compatibility with automatic placement equipment.
• Robust Process Compatibility: Suitable for both infrared and vapor phase reflow soldering processes.
• Environmental Compliance: Pb-free and RoHS compliant. Includes ESD protection (2000V HBM).

1.2 Target Applications

• Backlighting for dashboards, switches, and symbols.
• Telecommunication equipment indicators (telephones, fax machines).
• Flat backlighting for LCD panels.
• General purpose indicator applications.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

All parameters are specified at an ambient temperature (Ta) of 25°C. Exceeding these limits may cause permanent damage.

• Reverse Voltage (V_R): 5V
• Continuous Forward Current (I_F): 25 mA
• Peak Forward Current (I_FP): 60 mA (R6/Red), 100 mA (GH/Green, BH/Blue) at 1/10 duty cycle, 1kHz.
• Power Dissipation (P_d): 60 mW (R6), 95 mW (GH, BH).
• Operating Temperature (T_opr): -40°C to +85°C
• Storage Temperature (T_stg): -40°C to +90°C
• Soldering Temperature: Reflow: 260°C for 30 seconds. Hand soldering: 350°C for 3 seconds.

2.2 Electro-Optical Characteristics

Measured at Ta=25°C and I_F=20mA, unless otherwise noted. Typical values are provided for reference; design should be based on minimum/maximum specifications.

Note on Tolerances: Luminous Intensity (±11%), Dominant Wavelength (±1nm), Forward Voltage (±0.10V).

3. Binning System Explanation

The LEDs are sorted into bins based on luminous intensity at I_F=20mA to ensure consistency within a production batch.

3.1 Luminous Intensity Binning

• R6 (Red): Q bin (72.0-112 mcd), R bin (112-180 mcd).
• GH (Green): R bin (112-180 mcd), S bin (180-285 mcd), T bin (285-450 mcd).
• BH (Blue): N bin (28.5-45.0 mcd), P bin (45.0-72.0 mcd), Q bin (72.0-112 mcd).

This binning allows designers to select the appropriate brightness grade for their application, balancing cost and performance.

4. Performance Curve Analysis

The datasheet provides typical characteristic curves for each color variant (R6, GH, BH). These curves are essential for understanding device behavior under different operating conditions.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

The curves show the exponential relationship between current and voltage. The red LED (R6) has a significantly lower typical forward voltage (~2.0V) compared to the green and blue LEDs (~3.3V), due to the different semiconductor materials (AlGaInP vs. InGaN). This is a critical parameter for driver circuit design and power consumption calculation.

4.2 Luminous Intensity vs. Forward Current

Luminous intensity increases with forward current but not linearly. The curves show that intensity tends to saturate at higher currents. Operating at the recommended 20mA provides a good balance between brightness and efficiency/lifetime. Exceeding the maximum continuous current (25mA) is not advised as it can accelerate degradation.

4.3 Luminous Intensity vs. Ambient Temperature

LED light output is temperature-dependent. The curves demonstrate a decrease in luminous intensity as the ambient temperature rises. For the red LED (R6), the drop is more pronounced at higher temperatures compared to the green/blue (GH/BH) LEDs. This thermal derating must be accounted for in designs where high ambient temperatures or poor thermal management are expected.

4.4 Forward Current Derating Curve

This curve dictates the maximum allowable continuous forward current as a function of ambient temperature. To ensure reliability, the forward current must be reduced when operating above 25°C. Adherence to this curve is mandatory to prevent overheating and premature failure.

4.5 Spectral Distribution

The spectrum plots show the narrow emission bands characteristic of LEDs. The Red (R6) peaks around 632nm, Green (GH) around 518nm, and Blue (BH) around 468nm. The spectral bandwidth (Δλ) is approximately 20nm for red, 35nm for green, and 25nm for blue, indicating color purity.

4.6 Radiation Pattern

The polar diagrams confirm a wide, Lambertian-like emission pattern with a typical 120-degree viewing angle. This provides a broad, even illumination suitable for backlighting and indicator applications where wide viewing angles are required.

5. Mechanical and Package Information

5.1 Package Dimensions

The SMD package is designed for standard pick-and-place assembly. Key dimensions (in mm) include the body size, lead spacing, and overall height. All unspecified tolerances are ±0.1mm. The exact footprint and recommended pad layout should be derived from the detailed dimension drawing to ensure proper soldering and alignment.

6. Soldering and Assembly Guidelines

• Reflow Soldering: Maximum peak temperature of 260°C for 30 seconds is specified. Standard lead-free reflow profiles (IPC/JEDEC J-STD-020) are applicable.
• Hand Soldering: If necessary, a maximum iron tip temperature of 350°C for 3 seconds is allowed. Use minimal heat to avoid damaging the plastic lens or internal bonds.
• ESD Precautions: Although the device has 2000V HBM protection, standard ESD handling procedures should be followed during assembly.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The components are supplied in moisture-resistant packaging.

• Carrier Tape: 8mm width, on 7-inch diameter reels.
• Quantity per Reel: 2000 pieces.
• Moisture Protection: Packed with desiccant in an aluminum moisture-proof bag.

7.2 Label Explanation

The reel label contains critical information for traceability and correct application:

• P/N: Product Number (e.g., 19-137/R6GHBHC-A01/2T).
• QTY: Packing Quantity.
• CAT: Luminous Intensity Rank (Bin Code).
• HUE: Chromaticity Coordinates & Dominant Wavelength Rank.
• REF: Forward Voltage Rank.
• LOT No: Manufacturing Lot Number for traceability.

8. Application Design Considerations

8.1 Driver Circuit Design

Due to the diode's exponential I-V characteristic, current regulation (not voltage regulation) is essential for stable light output. A simple series resistor can be used for low-cost applications with a stable voltage supply. For optimal performance and efficiency, especially with varying supply voltages or temperature, a constant current driver is recommended. The forward voltage difference between red (~2.0V) and green/blue (~3.3V) LEDs must be considered when designing circuits for multi-color arrays.

8.2 Thermal Management

While SMD LEDs are efficient, a portion of the input power is converted to heat. The derating curve clearly shows the impact of temperature. For reliable operation, especially at high ambient temperatures or high drive currents, ensure adequate PCB copper area or other heat sinking methods are used to keep the junction temperature within safe limits. Poor thermal design will lead to reduced light output and shortened lifespan.

8.3 Optical Design

The 120-degree viewing angle provides wide coverage. For applications requiring more directed light, secondary optics (lenses, light guides) may be necessary. The water-clear resin color of these LEDs is suitable for applications where the true emitted color is desired without tinting from the package.

9. Technical Comparison and Differentiation

The key differentiator of this series is its multi-color capability within a single package footprint, enabled by different chip materials (AlGaInP for red, InGaN for green/blue). Compared to older through-hole LEDs, the SMD format offers substantial space savings, better suitability for automated assembly, and typically improved reliability due to the absence of bending stress on leads. The inclusion of ESD protection and compliance with RoHS and lead-free soldering standards makes it suitable for modern electronic manufacturing.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 Can I drive this LED at 30mA for more brightness?

No. The Absolute Maximum Rating for continuous forward current (I_F) is 25mA. Operating at 30mA exceeds this rating and risks immediate or long-term damage to the device. For higher brightness, select an LED from a bin with higher luminous intensity or consider a different LED model rated for higher current.

10.2 Why is the forward voltage different for the red LED?

The forward voltage is a fundamental property of the semiconductor material's bandgap. Red LEDs in this series use AlGaInP, which has a lower bandgap energy than the InGaN used for the green and blue LEDs. A lower bandgap translates to a lower forward voltage required to "turn on" the diode and cause light emission.

10.3 What does the "Bin Code" mean, and why is it important?

Due to manufacturing variations, LEDs are sorted (binned) after production based on key parameters like luminous intensity and color. The bin code (e.g., R, S, T for green) specifies the guaranteed minimum and maximum output for that group. For consistent appearance in an application (e.g., a multi-LED display), it is crucial to use LEDs from the same or adjacent bins.

11. Practical Design Case Study

Scenario: Designing a status indicator panel with red, green, and blue LEDs for a consumer device.

1. Current Setting: Choose a drive current of 20mA, which is the standard test condition and provides a good performance balance.
2. Current Limiting Resistors: Assuming a 5V supply (V_CC):
   • For Red (V_F ~2.0V): R = (5V - 2.0V) / 0.020A = 150Ω. Use the nearest standard value (e.g., 150Ω or 160Ω).
   • For Green/Blue (V_F ~3.3V): R = (5V - 3.3V) / 0.020A = 85Ω. Use 82Ω or 91Ω.
3. Brightness Matching: Check the luminous intensity bins. To achieve perceived brightness parity (human eye sensitivity varies by color), you may need to select different bins or adjust currents slightly. For example, a blue LED from the Q bin (72-112 mcd) might appear dimmer than a green LED from the T bin (285-450 mcd) at the same current.
4. Thermal Consideration: If the panel is inside an enclosed space that gets warm, consult the derating curve. At 60°C ambient, the maximum allowed continuous current is significantly lower than 25mA. You may need to reduce the drive current or improve ventilation.

12. Operating Principle

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons and holes recombine in the active region. The energy released during this recombination is emitted as photons (light). The color (wavelength) of the emitted light is determined by the bandgap energy of the semiconductor material used in the active region: AlGaInP for red/orange, and InGaN for green, blue, and white.

13. Technology Trends

The SMD LED market continues to evolve towards higher efficiency (more lumens per watt), increased power density, and improved color rendering. Miniaturization remains a key trend, enabling ever-smaller and higher-resolution displays and lighting arrays. There is also a strong focus on enhancing reliability and longevity under various operating conditions. The widespread adoption of InGaN technology has been instrumental in achieving high-brightness green and blue LEDs, which are essential for full-color displays and white LED lighting (often created by combining a blue LED with a phosphor).