SMD LED LTST-S06WGEBD Datasheet - Package Dimensions - White/Green/Red/Blue - 30mA - English Technical Document

1. Product Overview

The LTST-S06WGEBD is a surface-mount device (SMD) LED designed for automated printed circuit board (PCB) assembly. Its miniature size makes it suitable for space-constrained applications across a wide range of electronic equipment.

1.1 Features

• Compliant with RoHS (Restriction of Hazardous Substances) directives.
• Packaged in 12mm tape on 7-inch diameter reels for automated handling.
• Standard EIA (Electronic Industries Alliance) package outline.
• IC compatible, suitable for direct interfacing with logic circuits.
• Compatible with automatic pick-and-place assembly equipment.
• Withstands standard infrared (IR) reflow soldering processes.
• Preconditioned to JEDEC (Joint Electron Device Engineering Council) moisture sensitivity level 3.

1.2 Applications

• Telecommunication equipment (cordless/cellular phones).
• Office automation devices and notebook computers.
• Network systems and home appliances.
• Indoor signboards and status indicators.
• Front panel backlighting and signal/symbol luminaires.

2. Package Dimensions and Configuration

The LED is housed in a standard SMD package. All dimensions are in millimeters with a typical tolerance of ±0.1mm unless otherwise specified. The part number LTST-S06WGEBD incorporates multiple LED dice within a single package, allowing for different colors based on pin assignment.

3. Ratings and Characteristics

3.1 Absolute Maximum Ratings

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

3.2 Recommended IR Reflow Profile

For lead-free soldering processes, the recommended reflow profile should comply with the J-STD-020B standard. This ensures reliable solder joints without damaging the LED package due to excessive thermal stress.

3.3 Electrical and Optical Characteristics

Typical performance is measured at Ta=25°C with a forward current (IF) of 20mA, unless otherwise noted.

Notes:

• Tolerances: Luminous Flux ±10%, Dominant Wavelength ±1nm, Forward Voltage ±0.1V.
• ESD Caution: LEDs are sensitive to electrostatic discharge (ESD). Proper ESD precautions (wrist straps, grounded equipment) must be used during handling.
• Chromaticity coordinates are tested according to the CAS140B standard for each die/channel.

4. Binning Code System

The LEDs are sorted (binned) based on key optical parameters to ensure consistency in production runs.

4.1 RGB Luminous Intensity (IV) Binning

LEDs are categorized into bins based on their minimum and maximum luminous flux output at 20mA.

4.1.1 Individual Color Ranks

Green: G1 (4.00-5.65 lm), G2 (5.65-8.00 lm).
Red: R1 (1.92-2.75 lm), R2 (2.75-4.00 lm).
Blue: B1 (0.77-1.08 lm), B2 (1.08-1.58 lm).
Tolerance on each bin is ±10%.

4.1.2 Combined RGB Bin Codes

A single alphanumeric code on the product tag indicates the specific combination of Green, Red, and Blue intensity bins. For example, code A1 corresponds to G1, R1, B1.

4.2 RGB Dominant Wavelength (WD) Binning

LEDs are also binned by the peak wavelength of their emitted light.

4.2.1 Individual Wavelength Ranks

Green: AP (520-525 nm), AQ (525-530 nm).
Red: Single range (617-630 nm).
Blue: AC (465-470 nm), AD (470-475 nm).
Tolerance for each bin is ±1nm.

4.2.2 Combined RGB Wavelength Bin Codes

Similar to intensity, a code (D1-D4) specifies the combination of wavelength bins for Green, Red, and Blue dice.

4.3 White Luminous Intensity Binning

White LEDs are binned separately: W1 (4.40-5.85 lm), W2 (5.85-7.80 lm). Tolerance is ±10%.

4.4 White Chromaticity (CIE) Binning

White LEDs are further classified based on their chromaticity coordinates (x, y) on the CIE 1931 color space diagram. Bins (e.g., D1, D2, E1, E2, F1, F2) define specific quadrangular regions on this chart to ensure consistent white color appearance. Tolerance on each (x, y) coordinate is ±0.01.

5. Typical Performance Curves

The datasheet includes graphical representations of key characteristics, typically plotted against forward current or ambient temperature. These curves are essential for design engineers to predict LED behavior under non-standard conditions.

• Forward Current vs. Forward Voltage (I-V Curve): Shows the nonlinear relationship, critical for designing current-limiting circuits.
• Forward Current vs. Luminous Intensity/Flux: Demonstrates how light output increases with current, up to the maximum rating.
• Ambient Temperature vs. Relative Luminous Intensity: Illustrates the decrease in light output as junction temperature rises, highlighting the importance of thermal management.
• Spectral Power Distribution: For colored LEDs, this graph shows the relative intensity across wavelengths, defining the color purity and dominant wavelength.

6. User Guide and Handling

6.1 Cleaning

Do not use unspecified chemicals. If cleaning is necessary, immerse the LED in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute. Agitation or ultrasonic cleaning may damage the package.

6.2 Recommended PCB Pad Layout

A recommended land pattern (footprint) for the PCB is provided to ensure proper soldering, mechanical stability, and heat dissipation. Adhering to this layout prevents tombstoning and solder joint defects.

6.3 Tape and Reel Packaging Specifications

The LEDs are supplied in embossed carrier tape with a protective cover tape. Key dimensions of the tape pockets, pitch, and reel are specified to be compatible with standard automated assembly equipment.

6.4 Reel Specifications

• Reel diameter: 7 inches.
• Quantity per reel: 3000 pieces.
• Minimum order quantity for remnants: 500 pieces.
• Maximum consecutive missing components in the tape: 2.
• Packaging conforms to EIA-481-1-B specifications.

7. Application Cautions and Notes

7.1 Intended Use and Reliability

These LEDs are designed for general-purpose electronic equipment. For applications requiring exceptional reliability or where failure could risk life or health (e.g., aviation, medical devices, transportation safety systems), a specific reliability assessment and consultation with the manufacturer are mandatory. The standard product may not be qualified for such safety-critical applications.

7.2 General Design Considerations

• Current Limiting: Always operate the LED with a series current-limiting resistor or a constant-current driver to prevent exceeding the absolute maximum DC forward current, which can cause rapid degradation or failure.
• Thermal Management: Although power dissipation is low, ensuring adequate PCB copper area or thermal vias helps maintain a lower junction temperature, preserving luminous output and longevity.
• Reverse Voltage Protection: The maximum reverse voltage is only 5V. Incorporate protection (like a diode in parallel) if the LED could be exposed to reverse bias conditions.
• ESD Protection: Implement ESD protection components on PCB lines connected to the LED if the assembly environment or end-use poses an ESD risk.

8. Technical Deep Dive and Comparison

8.1 Semiconductor Materials and Color

The different colors are achieved using distinct semiconductor material systems:
- InGaN (Indium Gallium Nitride): Used for Green and Blue LEDs. This material system allows for efficient emission in the blue-to-green spectrum.
- AlInGaP (Aluminum Indium Gallium Phosphide): Used for the Red LED. This material is highly efficient for red and amber wavelengths.
- White Light: Typically generated by a blue InGaN die coated with a yellow phosphor. The mix of blue and yellow light appears white to the human eye. The binning for white focuses on chromaticity coordinates to define the "whiteness" (e.g., cool white, neutral white).

8.2 Understanding Binning for Design

The extensive binning system serves a crucial purpose. For aesthetic applications (like status indicators or backlighting where multiple LEDs are used side-by-side), selecting LEDs from the same intensity and chromaticity bin ensures uniform brightness and color, preventing a patchy or uneven appearance. For color-mixing applications (like creating tunable white light with RGB LEDs), knowing the precise wavelength and intensity bins allows for more accurate color calibration and control algorithm development.

8.3 Key Differentiators

This multi-die package (combining white and individual RGB colors) offers design flexibility in a single footprint, saving PCB space compared to using four separate LEDs. The preconditioning to JEDEC Level 3 indicates it can withstand 168 hours of floor life at ≤30°C/60% RH before reflow, which is important for manufacturing logistics.

9. Frequently Asked Questions (Based on Parameters)

Q: What is the typical forward voltage for the green LED at 20mA?
A: The forward voltage (VF) for the green die ranges from 2.4V (Min) to 3.3V (Max) at 20mA. A typical value for design might be around 2.8-3.0V, but the circuit should be designed to handle the maximum.

Q: Can I drive this LED at 30mA continuously?
A: Yes, 30mA is the absolute maximum DC forward current rating. For reliable long-term operation, it is often advisable to drive LEDs at a lower current, such as 20mA, to reduce thermal stress and increase lifespan.

Q: How do I interpret the bin code "A3" on the label?
A: Referring to the cross-table, code A3 corresponds to: Green in bin G2 (5.65-8.00 lm), Red in bin R1 (1.92-2.75 lm), and Blue in bin B1 (0.77-1.08 lm).

Q: Is this LED suitable for outdoor use?
A: The operating temperature range is -40°C to +85°C, which covers many outdoor conditions. However, the datasheet does not specify an Ingress Protection (IP) rating against dust and water. For outdoor use, additional sealing or conformal coating on the PCB would be necessary to protect the LED and its solder joints from moisture and contaminants.

10. Design and Application Example

Scenario: Designing a multi-color status indicator for a network router.

1. Requirement: A single component that can show White (power on), Green (connected), Red (error), and Blue (pairing mode).
2. Component Selection: The LTST-S06WGEBD is ideal as it integrates all four colors.
3. Circuit Design:
   • Use a microcontroller GPIO pin to control each color channel via a simple NPN transistor or a MOSFET as a low-side switch.
   • Calculate a current-limiting resistor for each channel. For the Green die at 20mA with a VF(max) of 3.3V and a 5V supply: R = (5V - 3.3V) / 0.02A = 85Ω. Use the next standard value (e.g., 91Ω or 100Ω) which will provide slightly less current, which is safe.
   • Repeat for other colors using their respective VF(max) values.
4. PCB Layout: Follow the recommended pad layout. Place the LED away from other heat-generating components. Ensure the microcontroller ground and LED circuit ground are properly connected.
5. Software: Implement control logic to illuminate the appropriate die based on system status. Ensure only one die is powered at a time if the absolute maximum total power dissipation for the package could be exceeded.