SMD5050N Blue LED Datasheet - Package 5.0x5.0x1.6mm - Voltage 3.2V - Power 0.306W - English Technical Document

1. Product Overview

The SMD5050N series is a surface-mount LED designed for applications requiring high brightness and reliability in a compact 5.0mm x 5.0mm footprint. This document provides the complete technical specifications for the Blue variant, model T5A003BA. The device features a standard SMD package suitable for automated assembly processes and is intended for use in backlighting, signage, decorative lighting, and general illumination.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

The following parameters define the limits beyond which permanent damage to the device may occur. All values are specified at an ambient temperature (T_s) of 25°C.

• Forward Current (I_F): 90 mA (Continuous)
• Forward Pulse Current (I_FP): 120 mA (Pulse Width ≤10ms, Duty Cycle ≤1/10)
• Power Dissipation (P_D): 306 mW
• Operating Temperature (T_opr): -40°C to +80°C
• Storage Temperature (T_stg): -40°C to +80°C
• Junction Temperature (T_j): 125°C
• Soldering Temperature (T_sld): Reflow soldering at 200°C or 230°C for a maximum of 10 seconds.

2.2 Electrical & Optical Characteristics

Typical operating parameters are measured at T_s=25°C with a forward current (I_F) of 60mA, which is the recommended test condition.

• Forward Voltage (V_F): Typical 3.2V, Maximum 3.4V (Tolerance: ±0.08V)
• Reverse Voltage (V_R): 5 V
• Reverse Current (I_R): Maximum 10 µA at V_R=5V
• Dominant Wavelength (λ_d): 460 nm (Refer to binned values in Section 2.4)
• Viewing Angle (2θ_1/2): 120° (Wide viewing angle, lens-less design)

3. Binning System Explanation

3.1 Luminous Flux Binning

The luminous flux output is categorized into bins to ensure consistency. Measurements are taken at I_F=60mA with a tolerance of ±7%.

• Code A4: Min 1.5 lm, Typ 2.0 lm
• Code A5: Min 2.0 lm, Typ 2.5 lm
• Code A6: Min 2.5 lm, Typ 3.0 lm
• Code A7: Min 3.0 lm, Typ 3.5 lm
• Code A8: Min 3.5 lm, Typ 4.0 lm

3.2 Dominant Wavelength Binning

The blue color is precisely controlled through wavelength binning.

• Code B1: 445 nm – 450 nm
• Code B2: 450 nm – 455 nm
• Code B3: 455 nm – 460 nm
• Code B4: 460 nm – 465 nm

4. Performance Curve Analysis

The datasheet includes several key performance graphs essential for circuit design and thermal management.

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

This graph shows the non-linear relationship between voltage and current. The forward voltage increases with current and is also temperature-dependent. Designers must use this curve to calculate power dissipation (V_F * I_F) and ensure the driver can supply the necessary voltage, especially at low temperatures where V_F increases.

4.2 Relative Luminous Flux vs. Forward Current

This curve illustrates how light output scales with drive current. While output increases with current, efficiency typically decreases at higher currents due to increased thermal effects. Operating significantly above the recommended 60mA test point may reduce lifetime and shift color.

4.3 Relative Spectral Power vs. Junction Temperature

For blue LEDs, the peak wavelength can shift with junction temperature (typically 0.1-0.3 nm/°C). This graph is critical for applications requiring stable color output. Higher junction temperatures cause a redshift (longer wavelength), which must be accounted for in thermal design.

4.4 Spectral Power Distribution

This graph displays the full emission spectrum of the blue LED, showing a narrow peak around the dominant wavelength (e.g., 460nm). The full width at half maximum (FWHM) is typically 20-30nm for InGaN-based blue LEDs. Understanding the spectrum is vital for color mixing applications or when using phosphor conversion for white light.

5. Mechanical & Package Information

5.1 Package Dimensions

The SMD5050N package has nominal dimensions of 5.0mm (L) x 5.0mm (W) x 1.6mm (H). Detailed mechanical drawings with tolerances are provided: .X dimensions have a tolerance of ±0.10mm, and .XX dimensions have a tolerance of ±0.05mm.

5.2 Recommended Pad Layout & Stencil Design

For reliable soldering, a specific pad pattern is recommended. The pad design ensures proper solder fillet formation and mechanical strength. A corresponding stencil aperture design is provided to control solder paste volume, which is crucial for achieving a reliable solder joint without bridging or insufficient solder.

5.3 Polarity Identification

The LED cathode is typically marked on the package. Correct polarity must be observed during assembly to prevent reverse bias, which is limited to 5V.

6. Soldering & Assembly Guidelines

6.1 Moisture Sensitivity & Baking

The SMD5050N package is moisture-sensitive (MSL classified per IPC/JEDEC J-STD-020C).

• Storage: Store in original sealed bag with desiccant at <30°C and <85% RH.
• Floor Life: After opening the sealed bag, components should be used within 12 hours if stored at <30°C/<60% RH.
• Baking Required If: The bag has been opened for >12 hours, or the humidity indicator card shows high humidity.
• Baking Procedure: Bake at 60°C for 24 hours. Do not exceed 60°C. Use within 1 hour after baking or store in a dry cabinet (<20% RH).

6.2 Reflow Soldering Profile

The LED can withstand a lead-free reflow profile with a peak temperature of 200°C or 230°C for a maximum of 10 seconds. Consult the specific profile recommendations to minimize thermal stress on the silicone encapsulant and wire bonds.

7. Electrostatic Discharge (ESD) Protection

Blue LEDs are sensitive to electrostatic discharge. Failure modes include increased leakage current (reduced brightness, color shift) or catastrophic failure (dead LED).

• Prevention Measures: Use grounded anti-static workstations, floor mats, and wrist straps.
• Personnel: Operators must wear anti-static garments and gloves.
• Equipment: Use ionizers and ensure soldering irons are properly grounded.
• Packaging: Use conductive or anti-static materials for handling and transport.

8. Application Circuit Design

8.1 Driving Method

Constant Current Drive is strongly recommended. LEDs are current-driven devices; their light output is proportional to current, not voltage. A constant current source provides stable brightness and protects the LED from thermal runaway.

8.2 Current Limiting Resistor (for Constant Voltage Source)

If a constant voltage source (e.g., a regulated DC supply) must be used, a series current-limiting resistor is mandatory. The resistor value is calculated using Ohm's Law: R = (V_supply - V_F) / I_F. The power rating of the resistor must be sufficient: P_R = (I_F)² * R. This method is less efficient and less stable than constant current drive, as V_F varies with temperature.

8.3 Connection Sequence

When connecting an LED module to a driver, follow this sequence to avoid voltage spikes: 1) Identify LED and driver polarity. 2) Connect the driver output to the LED module. 3) Finally, connect the driver input to the power source. This prevents connecting a live driver to the LEDs.

9. Handling & Storage Precautions

• Avoid Direct Handling: Do not touch the LED lens with bare hands. Contaminants like skin oils can permanently stain the silicone, reducing light output.
• Use Proper Tools: Use vacuum pick-up tools or soft-tipped tweezers. Avoid excessive mechanical pressure on the lens, which can damage the wire bonds or die.
• Long-Term Storage: For opened packages, store in a dry cabinet with nitrogen purge or desiccant at 5-30°C and <60% RH.

10. Product Nomenclature & Ordering Information

The model number follows a structured code: T □□ □□ □ □ □ – □□□ □□. Key elements include:

• Package Code (5A): Denotes the 5050N package size.
• Chip Count: Indicates the number of LED dies within the package (e.g., 1, 2, 3).
• Color Code (B): B for Blue. Other codes: R (Red), Y (Yellow), G (Green), etc.
• Optics Code (00): 00 indicates no secondary lens (primary lens only).
• Flux Bin Code (e.g., A6): Specifies the luminous flux output bin.
• Wavelength Bin Code (e.g., B3): Specifies the dominant wavelength bin.

11. Typical Application Scenarios

• Backlighting: LCD TV and monitor edge-lighting, advertising light boxes.
• Decorative Lighting: Architectural accent lighting, cove lighting, signage.
• General Illumination: As a component in white LED modules using phosphor conversion.
• Automotive Interior Lighting: Dashboard, footwell, and ambient lighting.
• Consumer Electronics: Status indicators, keyboard backlights.

12. Design Considerations & FAQs

12.1 How do I select the right current?

Operate at or below the recommended test current of 60mA for optimal balance of brightness, efficiency, and lifetime. Higher currents increase light output but generate more heat, accelerating lumen depreciation and potentially shifting color.

12.2 Why is thermal management important?

LED performance and lifetime are inversely related to junction temperature. High T_j reduces light output (lumen depreciation), causes a color shift (for blue and white LEDs), and can lead to premature failure. Ensure adequate heat sinking, especially in high-power or enclosed applications.

12.3 Can I connect multiple LEDs in series or parallel?

Series connection is preferred when using a constant current driver, as the same current flows through all LEDs. Ensure the driver's compliance voltage is higher than the sum of the V_F of all LEDs in the string. Parallel connection is generally not recommended due to V_F binning variations, which can cause current imbalance and uneven brightness/overheating. If parallel connection is unavoidable, use a separate current-limiting resistor for each parallel branch.

13. Technical Comparison & Trends

The SMD5050N, with its 5.0x5.0mm footprint, offers a larger emitting area and higher potential light output than smaller packages like 3528 or 3014. It is a mature, cost-effective solution for applications not requiring the ultra-high density of newer, smaller packages. The industry trend is towards higher efficiency (lumens per watt) and improved color consistency (tighter binning). Future developments may include chip-scale packaging (CSP) and improved phosphor technologies for white LEDs derived from blue emitters.